Sanofi (SNY) 20-F 4 Mar 21 2020 FY Annual report (foreign) Financial data

Cover page

Cover page	12 Months Ended
	Dec. 31, 2020shares
Entity Information [Line Items]
Document Type	20-F
Document Registration Statement	false
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Document Shell Company Report	false
Entity File Number	001-31368
Entity Registrant Name	Sanofi
Entity Incorporation, State or Country Code	I0
Entity Address, Address Line One	54, Rue La Boétie
Entity Address, Postal Zip Code	75008
Entity Address, City or Town	Paris
Entity Address, Country	FR
Contact Personnel Fax Number	33 1 53 77 43 03
Entity Common Stock, Shares Outstanding	1,250,690,553
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Accounting Standard	International Financial Reporting Standards
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0001121404
Business Contact
Entity Information [Line Items]
Entity Address, Address Line One	54, Rue La Boétie
Entity Address, Postal Zip Code	75008
Entity Address, City or Town	Paris
Entity Address, Country	FR
Contact Personnel Name	Karen Linehan
City Area Code	33
Local Phone Number	1 53 77 40 00
American Depositary Shares, each representing one half of one ordinary share, par value €2 per share
Entity Information [Line Items]
Title of 12(b) Security	American Depositary Shares, each representing one half of one ordinary share, par value €2 per share
Security Exchange Name	NASDAQ
Ordinary shares, par value €2 per share
Entity Information [Line Items]
Title of 12(b) Security	Ordinary shares, par value €2 per share
Security Exchange Name	NASDAQ

Consolidated balance sheets

Consolidated balance sheets - EUR (€) € in Millions		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Property, plant and equipment		€ 9,365	€ 9,717	€ 9,651
Right-of-use assets	[1]	1,198	1,300	0
Goodwill		44,364	44,519	44,235
Other intangible assets		18,421	16,572	21,889
Investments accounted for using the equity method		201	3,591	3,402
Other non-current assets		2,734	2,503	2,815
Non-current income tax assets		248	164	156
Deferred tax assets		4,212	5,434	4,613
Non-current assets		80,743	83,800	86,761
Inventories		8,352	7,994	7,477
Accounts receivable		7,491	7,937	7,260
Other current assets		2,737	2,445	2,023
Current income tax assets		1,208	808	894
Cash and cash equivalents		13,915	9,427	6,925
Current assets		33,703	28,611	24,579
Assets held for sale or exchange		83	325	68
Total assets		114,529	112,736	111,408
Equity and liabilities
Equity attributable to equity holders of Sanofi		63,001	58,934	58,876
Equity attributable to non-controlling interests		146	174	159
Total equity		63,147	59,108	59,035
Long-term debt		19,745	20,131	22,007
Non-current lease liabilities	[2]	931	987	0
Non-current liabilities related to business combinations and to non-controlling interests		387	508	963
Non-current provisions and other non-current liabilities		7,536	7,641	7,206
Non-current income tax liabilities		1,733	1,680	1,407
Deferred tax liabilities		1,770	2,294	3,414
Non-current liabilities		32,102	33,241	34,997
Accounts payable		5,295	5,313	5,041
Current liabilities related to business combinations and to non-controlling interests		218	292	341
Current provisions and other current liabilities		10,132	9,703	8,969
Current income tax liabilities		604	258	392
Current lease liabilities	[2]	232	261	0
Short-term debt and current portion of long-term debt		2,767	4,554	2,633
Current liabilities		19,248	20,381	17,376
Liabilities related to assets held for sale or exchange		32	6	0
Total equity and liabilities		€ 114,529	€ 112,736	€ 111,408
[1]	Includes the effects of first-time application of IFRS 16 on leases using the modified retrospective approach, effective January 1, 2019.
[2]	Includes the effects of first-time application of IFRS 16 on leases using the modified retrospective approach, effective January 1, 2019.

Consolidated income statements

Consolidated income statements - EUR (€) € in Millions, shares in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Profit (loss) [abstract]
Net sales		€ 36,041	€ 36,126	€ 34,463
Other revenues		1,328	1,505	1,214
Cost of sales		(12,157)	(11,976)	(11,435)
Gross profit		25,212	25,655	24,242
Research and development expenses		(5,529)	(6,018)	(5,894)
Selling and general expenses		(9,390)	(9,883)	(9,859)
Other operating income		696	825	484
Other operating expenses		(1,415)	(1,207)	(548)
Amortization of intangible assets		(1,681)	(2,146)	(2,170)
Impairment of intangible assets		(330)	(3,604)	(718)
Fair value remeasurement of contingent consideration		124	238	117
Restructuring costs and similar items		(1,064)	(1,062)	(1,480)
Other gains and losses, and litigation		136	327	502
Gains on disposals of investments		7,382	0	0
Operating income		14,141	3,125	4,676
Financial expenses		(390)	(444)	(435)
Financial income		53	141	164
Income before tax and investments accounted for using the equity method		13,804	2,822	4,405
Income tax expense		(1,813)	(139)	(481)
Share of profit/(loss) from investments accounted for using the equity method		359	255	499
Net income excluding the exchanged/held-for-exchange Animal Health business		12,350	2,938	4,423
Net income/(loss) of the exchanged/held-for-exchange Animal Health business	[1]	0	(101)	(13)
Net income		12,350	2,837	4,410
Net income attributable to non-controlling interests		36	31	104
Net income attributable to equity holders of Sanofi		€ 12,314	€ 2,806	€ 4,306
Average number of shares outstanding (in shares)		1,253.6	1,249.9	1,247.1
Average number of shares after dilution (in shares)		1,260.1	1,257.1	1,255.2
Basic earnings per share (in euros per share)		€ 9.82	€ 2.24	€ 3.45
Basic earnings per share excluding the exchanged/held-for-exchange Animal Health business (in euros per share)		9.82	2.33	3.46
Diluted earnings per share (in euros per share)		9.77	2.23	3.43
Diluted earnings per share excluding the exchanged/held-for-exchange Animal Health business (in euros per share)		€ 9.77	€ 2.31	€ 3.44
[1]	Net income/losses arising from the divestment of the Animal Health business are presented separately in accordance with IFRS 5 (Non-Current Assets Held for Sale and Discontinued Operations).

Consolidated statements of comp

Consolidated statements of comprehensive income - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of comprehensive income [abstract]
Net income	€ 12,350	€ 2,837	€ 4,410
Attributable to equity holders of Sanofi	12,314	2,806	4,306
Attributable to non-controlling interests	36	31	104
Other comprehensive income:
Actuarial gains/(losses)	(268)	(382)	201
Change in fair value of equity instruments included in financial assets and financial liabilities	320	106	(537)
Tax effects	(40)	113	31
Items not subsequently reclassifiable to profit or loss	12	(163)	(305)
Change in fair value of debt instruments included in financial assets	15	28	(4)
Change in fair value of cash flow hedges	4	(13)	3
Change in currency translation differences	(3,978)	751	1,194
Tax effects	(63)	47	71
Items subsequently reclassifiable to profit or loss	(4,022)	813	1,264
Other comprehensive income for the period, net of taxes	(4,010)	650	959
Comprehensive income	8,340	3,487	5,369
Comprehensive income, attributable to equity holders of Sanofi	8,324	3,457	5,269
Comprehensive income, attributable to non-controlling interests	€ 16	€ 30	€ 100

Consolidated statements of chan

Consolidated statements of changes in equity - EUR (€) € in Millions		Total		Share capital	Additional paid-in capital	Treasury shares	Reserves and retained earnings	Stock options and other share- based payments	Other comprehensive income	Attributable to equity holders of Sanofi		Attributable to non- controlling interests
Beginning balance at Dec. 31, 2017	[1]	€ 58,239		€ 2,508	€ 58	€ (14)	€ 52,804	€ 3,298	€ (584)	€ 58,070		€ 169
Other comprehensive income for the period		959					(305)		1,268	963		(4)
Net income for the period		4,410					4,306			4,306		104
Comprehensive income		5,369					4,001		1,268	5,269		100
Dividend paid out of earnings		(3,773)					(3,773)			(3,773)
Payment of dividends to non-controlling interests		(97)										(97)
Share repurchase program	[2]	(1,100)				(1,100)				(1,100)
Reduction in share capital	[2]	0		(24)	(213)	880	(643)
Exercise of stock options	[2]	59		2	57					59
Share-based payment plans:
Exercise of stock options	[2]	59		2	57					59
Issuance of restricted shares and vesting of existing restricted shares	[2],[3]	0		4	(4)	80	(80)
Employee share ownership plan	[2]	120		5	115					120
Proceeds from sale of treasury shares on exercise of stock options		1				1				1
Value of services obtained from employees		284						284		284
Tax effects of the exercise of stock options		14						14		14
Other changes arising from issuance of restricted shares	[4]	13					13			13
Change in non-controlling interests without loss of control		(65)					(68)			(68)		3
Change in non-controlling interests arising from divestment		(16)										(16)
Ending balance (Increase (decrease) due to changes in accounting policy) at Dec. 31, 2018		(13)					839		(852)	(13)
Ending balance at Dec. 31, 2018		59,035		2,495	13	(153)	53,093	3,596	(168)	58,876		159
Other comprehensive income for the period		650					(162)		813	651		(1)
Net income for the period		2,837					2,806			2,806		31
Comprehensive income		3,487					2,644		813	3,457		30
Dividend paid out of earnings		(3,834)					(3,834)			(3,834)
Payment of dividends to non-controlling interests		(14)										(14)
Share repurchase program	[2]	(12)				(12)				(12)
Exercise of stock options	[2]	147		6	141					147
Share-based payment plans:
Exercise of stock options	[2]	147		6	141					147
Issuance of restricted shares and vesting of existing restricted shares	[2],[3]	0		7	(7)	153	(153)
Proceeds from sale of treasury shares on exercise of stock options		3				3				3
Value of services obtained from employees		252						252		252
Tax effects of the exercise of stock options		15						15		15
Other changes arising from issuance of restricted shares	[4]	30					30			30
Change in non-controlling interests without loss of control		(8)					(7)			(7)		(1)
Other	[5]	7					7			7
Ending balance at Dec. 31, 2019		59,108		2,508	147	(9)	51,780	3,863	645	58,934		174
Other comprehensive income for the period		(4,010)					13		(4,003)	(3,990)		(20)
Net income for the period		12,350					12,314			12,314		36
Comprehensive income		8,340					12,327		(4,003)	8,324		16
Dividend paid out of earnings		(3,937)					(3,937)			(3,937)
Payment of dividends to non-controlling interests		(44)										(44)
Share repurchase program	[2]	(822)				(822)				(822)
Exercise of stock options	[2]	51		2	49					51
Share-based payment plans:
Exercise of stock options	[2]	51		2	49					51
Issuance of restricted shares and vesting of existing restricted shares	[2],[3]	0		3	(3)	126	(126)
Employee share ownership plan		174		5	169					174
Value of services obtained from employees		274						274		274
Tax effects of the exercise of stock options		1						1		1
Other changes arising from issuance of restricted shares		2	[4]				2			2	[4]
Ending balance at Dec. 31, 2020		€ 63,147		€ 2,518	€ 362	€ (705)	€ 60,046	€ 4,138	€ (3,358)	€ 63,001		€ 146
[1]	Includes the effects of first-time application of IFRS 15 on revenue recognition.
[2]	See Notes D.15.1., D.15.3., D.15.4. and D.15.5.
[3]	This line includes the use of existing shares to fulfill vested rights under restricted share plans.
[4]	Issuance of restricted shares to former employees of the Animal Health business and the European Generics business subsequent to the date of divestment.
[5]	This line includes the impact of the settlement of a put option granted to non-controlling interests in connection with a divestment.

Consolidated statements of ch_2

Consolidated statements of changes in equity (Parenthetical) - € / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of changes in equity [abstract]
Dividends paid, ordinary shares per share	€ 3.15	€ 3.07	€ 3.03

Consolidated statements of cash

Consolidated statements of cash flows - EUR (€) € in Millions		Feb. 14, 2020	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Statement of cash flows [abstract]
Net income attributable to equity holders of Sanofi			€ 12,314		€ 2,806		€ 4,306
Net (income)/loss of the exchanged/held-for-exchange Animal Health business	[1]		0		101		13
Non-controlling interests, excluding BMS	[2]		36		31		22
Share of undistributed earnings from investments accounted for using the equity method			(339)		(192)		(471)
Depreciation, amortization and impairment of property, plant and equipment, right-of-use assets and intangible assets(b)			3,684		7,452		4,279
Gains and losses on disposals of non-current assets, net of tax	[3]		(301)		(286)		(797)
Gain on Regeneron investment arising from transaction of May 29, 2020, net of tax(h)	[4]		(6,880)		0		0
Net change in deferred taxes			(214)		(1,753)		(727)
Net change in non-current provisions and other non-current liabilities	[5]		(142)		58		(265)
Cost of employee benefits (stock options and other share-based payments)			274		252		284
Impact of the workdown of acquired inventories remeasured at fair value			53		3		114
Other profit or loss items with no cash effect(i)	[6]		(711)		(309)		69
Operating cash flow before changes in working capital and excluding the exchanged/held-for-exchange Animal Health business			7,774		8,163		6,827
(Increase)/decrease in inventories			(593)		(547)		(701)
(Increase)/decrease in accounts receivable			(134)		(462)		(35)
Increase/(decrease) in accounts payable			86		169		270
Net change in other current assets and other current liabilities			316		421		(814)
Net cash provided by/(used in) operating activities excluding the exchanged/held-for-exchange Animal Health business	[7]		7,449		7,744		5,547
Acquisitions of property, plant and equipment and intangible assets			(2,114)		(1,816)		(1,977)
Acquisitions of consolidated undertakings and investments accounted for using the equity method	[8]		(5,336)		(488)		(12,857)
Acquisitions of other equity investments			(137)		(38)		(137)
Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax		€ 311	918	[9]	1,224	[9]	2,163	[9]
Proceeds from sales of investments accounted for using equity method			10,370		0		0
Net change in other non-current assets			(113)		(94)		(58)
Net cash provided by/(used in) investing activities excluding the exchanged/held-for-exchange Animal Health business			3,588		(1,212)		(12,866)
Net cash inflow from the exchange of the Animal Health business for BI’s Consumer Healthcare business			0		154		(6)
Issuance of Sanofi shares			203		162		177
Dividends paid:
to shareholders of Sanofi			(3,937)		(3,834)		(3,773)
to non-controlling interests, excluding BMS	[2]		(44)		(14)		(14)
Payments received/(made) on changes of ownership interest in a subsidiary without loss of control			0		(7)		(77)
Additional long-term debt contracted			2,019		1,997		9,677
Repayments of long-term debt			(3,952)		(2,067)		(787)
Repayments of lease liabilities	[10]		(234)		(267)		0
Net change in short-term debt			282		(154)		(168)
Acquisitions of treasury shares			(822)		(9)		(1,101)
Net cash provided by/(used in) financing activities excluding the exchanged/held-for-exchange Animal Health business			(6,485)		(4,193)		3,934
Impact of exchange rates on cash and cash equivalents			(64)		9		1
Net change in cash and cash equivalents			4,488		2,502		(3,390)
Cash and cash equivalents, beginning of period			9,427		6,925		10,315
Cash and cash equivalents, end of period			€ 13,915		€ 9,427		€ 6,925
[1]	Net income/losses arising from the divestment of the Animal Health business are presented separately in accordance with IFRS 5 (Non-Current Assets Held for Sale and Discontinued Operations).
[2]	See Note C.2.
[3]	Includes non-current financial assets.
[4]	The gain on the sale of Regeneron shares is presented net of taxes, including deferred taxes of €115 million.
[5]	This line item includes contributions paid to pension funds (see Note D.19.1.).
[6]	This line mainly comprises unrealized foreign exchange gains and losses arising on the remeasurement of monetary items in non-functional currencies, and on instruments used to hedge such items.
[7]	2020 2019 2018 • Income tax paid (2,051) (1,695) (2,058) • Interest paid (315) (379) (313) • Interest received 37 92 72 • Dividends received from non-consolidated entities — — 1
[8]	This line item includes payments made in respect of contingent consideration identified and recognized as a liability in business combinations.
[9]	This line item includes proceeds from disposals of investments in consolidated entities and of other non-current financial assets. For 2020, it includes the sale to Baxter of operations relating to Seprafilm ® for a selling price before taxes of €311 million and the divestment of certain established prescription products for €97 million before taxes, plus contingent consideration of €167 million before taxes relating to a past divestment. For 2019, it includes the proceeds from the divestments of Sanofi's entire equity interests in Alnylam for €706 million and in MyoKardia for €118 million (see Note D.7.1.). For 2018, it includes an amount of €1,598 million (net of transaction costs) for the divestment of the European Generics business (see Note D.2.2.).
[10]	Includes the effects of first-time application of IFRS16 on leases using the modified retrospective approach, effective January 1,2019.

Consolidated statements of ca_2

Consolidated statements of cash flows (Parenthetical) - EUR (€) € in Millions	May 29, 2020	Feb. 14, 2020	May 02, 2019	Jun. 30, 2019	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Statement [Line Items]
Income tax paid					€ (2,051)		€ (1,695)		€ (2,058)
Interest paid					(315)		(379)		(313)
Interest received					37		92		72
Dividends received from non-consolidated entities					0		0		1
Proceeds from disposals of investments		€ 311			918	[1]	1,224	[1]	2,163	[1]
Proceeds from sales of investments accounted for using equity method					10,370		0		0
Regeneron
Statement [Line Items]
Proceeds from sales of investments accounted for using equity method	€ 10,370
Deferred income tax on disposal of investments					115
Seprafilm [Member]
Statement [Line Items]
Proceeds from disposals of investments					311
Pharmaceuticals
Statement [Line Items]
Proceeds from disposals of investments					97
European generic business
Statement [Line Items]
Proceeds from disposals of investments									€ 1,598
Securities quoted in an active market | Alnylam Pharmaceuticals, Inc
Statement [Line Items]
Proceeds from sales of investments accounted for using equity method			€ 706				706
Securities quoted in an active market | MyoKardia, Inc
Statement [Line Items]
Proceeds from sales of investments accounted for using equity method				€ 118			€ 118
Contingent consideration relating to divestments
Statement [Line Items]
Proceeds from disposals of investments					€ 167
[1]	This line item includes proceeds from disposals of investments in consolidated entities and of other non-current financial assets. For 2020, it includes the sale to Baxter of operations relating to Seprafilm ® for a selling price before taxes of €311 million and the divestment of certain established prescription products for €97 million before taxes, plus contingent consideration of €167 million before taxes relating to a past divestment. For 2019, it includes the proceeds from the divestments of Sanofi's entire equity interests in Alnylam for €706 million and in MyoKardia for €118 million (see Note D.7.1.). For 2018, it includes an amount of €1,598 million (net of transaction costs) for the divestment of the European Generics business (see Note D.2.2.).

Introduction

Introduction	12 Months Ended
	Dec. 31, 2020
General Information About Financial Statements [Abstract]
Introduction	Introduction Sanofi, together with its subsidiaries (collectively “Sanofi”, “the Group” or “the Company”), is a global healthcare leader engaged in the research, development and marketing of therapeutic solutions focused on patient needs. Sanofi is listed in Paris (Euronext: SAN) and New York (Nasdaq: SNY). The consolidated financial statements for the year ended December 31, 2020, and the notes thereto, were signed off by the Sanofi Board of Directors on February 4, 2021.

Basis of preparation

Basis of preparation	12 Months Ended
	Dec. 31, 2020
Corporate Information And Statement Of IFRS Compliance [Abstract]
Basis of preparation	Basis of preparation A.1. International financial reporting standards (IFRS) The consolidated financial statements cover the twelve-month periods ended December 31, 2020, 2019 and 2018. In accordance with Regulation No. 1606/2002 of the European Parliament and Council of July 19, 2002 on the application of international accounting standards, Sanofi has presented its consolidated financial statements in accordance with IFRS since January 1, 2005. The term “IFRS” refers collectively to international accounting and financial reporting standards (IASs and IFRSs) and to interpretations of the interpretations committees (SIC and IFRIC) with mandatory application as of December 31, 2020. The consolidated financial statements of Sanofi as of December 31, 2020 have been prepared in compliance with IFRS as issued by the International Accounting Standards Board (IASB) and with IFRS as endorsed by the European Union as of December 31, 2020. Sanofi has also early adopted, with effect from January 1, 2020, the second amendment to IFRS 9 on interest rate benchmark reform, which was endorsed by the European Union between the end of the reporting period and the date on which the financial statements were closed off (see Note A.2.2.). IFRS as endorsed by the European Union as of December 31, 2020 are available under the heading “IFRS Financial Statements” via the following web link: https://www.efrag.org/Endorsement. The consolidated financial statements have been prepared in accordance with the IFRS general principles of fair presentation, going concern, accrual basis of accounting, consistency of presentation, materiality, and aggregation. A.2. New standards, amendments and interpretations A.2.1. New standards applicable from January 1, 2020 During 2018, the IASB published a number of amendments mandatorily applicable at the earliest from January 1, 2020 onwards. These include “Definition of a Business” (amendment to IFRS 3), issued October 22, 2018, which applies prospectively to business combinations from January 1, 2020 onwards. Those amendments do not have a material impact on the consolidated financial statements for the year ended December 31, 2020. On May 28, 2020, the IASB issued “Covid-19-Related Rent Concessions”, an amendment to IFRS 16. The amendment, which came into force on October 12, 2020, allows lessees not to account for rent concessions as lease modifications if they are a direct consequence of Covid-19 and meet certain conditions. The impact of first-time application of this amendment was immaterial. In its consolidated financial statements for the year ended December 31, 2019, and with no material impact, Sanofi (i) early adopted the Phase 1 amendment to IFRS 9 relating to interest rate benchmark reform and (ii) in light of the IFRIC agenda decision of November 2019, reviewed the lease term of contracts cancellable without the payment of a penalty, either by the lessor or the lessee, in order to take into account the concept of "economic penalty". A.2.2. New pronouncements issued by the IASB and applicable from 2021 or later This note describes standards, amendments and interpretations issued by the IASB that will have mandatory application in 2021 or subsequent years, and Sanofi’s position regarding future application. On January 23, 2020, the IASB issued “Classification of Liabilities as Current or Non-current”, an amendment to IAS 1. On May 14, 2020, the IASB issued “Reference to the Conceptual Framework”, an amendment to IFRS 3; “Proceeds before Intended Use”, an amendment to IAS 16; “Onerous Contracts – Cost of Fulfilling a Contract”, an amendment to IAS 37; and “Annual Improvements to IFRS standards 2018-2020”. Sanofi does not expect a material impact from those amendments, which are applicable at the earliest from January 1, 2022 (subject to endorsement by the European Union). Sanofi will not early adopt those amendments. On August 27, 2020, the IASB issued a second amendment (Phase 2) to IFRS 9, relating to interest rate benchmark reform. Sanofi has early adopted that amendment in the consolidated financial statements for the year ended December 31, 2020. The hedging instruments contracted by Sanofi affected by interest rate benchmark reform are the interest rate swaps described in note D.20b.), maturing from 2022. Fair value hedging relationships consist of swapping fixed-rate euro-denominated bonds to the overnight benchmark rate applicable in euros (Eonia), with a perfect alignment of critical terms between hedged items and hedging instruments. Consequently, those hedging relationships currently have no ineffective portion, and that will remain the case once Eonia is replaced by Ester, the new euro overnight benchmark rate. Cash flow hedging relationships consist of swapping floating-rate synthetic debt (combination of fixed-rate bonds and fixed-to-Eonia interest rate swaps) to fixed rates, with the same perfect alignment of critical terms between hedged items and hedging instruments. Sanofi expects that Eonia will be replaced by Ester simultaneously in the interest rate swap contracts affected, and hence believes that the cash flow hedging relationships in question will remain fully effective. Consequently, Sanofi does not expect the interest rate benchmark reform to have a material impact on its hedging relationships. A.3. Use of estimates and judgments The preparation of financial statements requires management to make reasonable estimates and assumptions based on information available at the date of the finalization of the financial statements. Those estimates and assumptions may affect the reported amounts of assets, liabilities, revenues and expenses in the financial statements, and disclosures of contingent assets and contingent liabilities as of the date of the review of the financial statements. Examples of estimates and assumptions include: • amounts deducted from sales for projected sales returns, chargeback incentives, rebates and price reductions (see Notes B.13 and D.23.); • impairment of property, plant and equipment, intangible assets, and investments accounted for using the equity method (see Notes B.6. and D.5.); • the valuation of goodwill and the valuation and estimated useful life of acquired intangible assets (see Notes B.3.2., B.4., D.4. and D.5.); • the measurement of equity investments in unquoted entities (see Notes B.8.5. and D.12.); • the measurement of contingent consideration receivable in connection with asset divestments (see Notes B.8.5. and D.12.) and of contingent consideration payable (see Notes B.3. and D.18.); • the measurement of financial assets at amortized cost (see Note B.8.5.); • the amount of post-employment benefit obligations (see Notes B.23. and D.19.1.); • the amount of liabilities or provisions for restructuring, litigation, tax risks and environmental risks (see Notes B.12., B.19., B.20., D.19. and D.22.); and • the amount of deferred tax assets resulting from tax losses available for carry-forward and deductible temporary differences (see Notes B.22. and D.14.). Actual results could differ from these estimates. A.4. Hyperinflation Under IAS 29, (Financial Reporting in Hyperinflationary Economies), non-monetary balance sheet items must be restated using a general price index; monetary items are not restated. Items in the income statement and the statement of comprehensive income must be restated by applying the change in the general price index from the dates when the income and expense items were initially recorded in the financial statements. In Lebanon, the cumulative inflation rate over the last three years is in excess of 100%, based on a combination of indices used to measure inflation in that country. On November 10, 2020, the IPTF (International Practices Task Force) recommended that Lebanon be treated as a hyperinflationary economy. Consequently, Sanofi decided to apply IAS 29 with effect from 2020. The resulting monetary foreign exchange loss in respect of the impact of hyperinflation in Lebanon was recognized in the Sanofi financial statements as of December 31, 2020, and is immaterial. In 2020, Sanofi continued to account for subsidiaries based in Venezuela using the full consolidation method, on the basis that the criteria for control as specified in IFRS 10 (Consolidated Financial Statements) are still met. In 2018, the Venezuelan government made further changes to the foreign exchange system. At the end of August 2018 the “DICOM” rate, which had been the compulsory rate since the end of January 2018, was abolished and replaced by the “PETRO” rate with a floating US dollar/bolivar parity. At the same time, the strong bolivar (“VEF”) was also replaced by a new currency known as the sovereign bolivar (“VES”), reflecting a 1-for-100,000 devaluation. Consequently, the contribution of the Venezuelan subsidiaries to the consolidated financial statements is immaterial. In Argentina, the cumulative rate of inflation over the last three years is in excess of 100%, based on a combination of indices used to measure inflation in that country. Consequently, Sanofi has treated Argentina as a hyperinflationary economy from July 1, 2018 onwards, and applies IAS 29. As a result, an immaterial monetary foreign exchange loss was recognized in the Sanofi financial statements as of December 31, 2020, December 31, 2019 and December 31, 2018 in respect of the impact of hyperinflation in Argentina. A.5. Withdrawal of the United Kingdom from the European Union The withdrawal of the United Kingdom from the European Union does not pose any major issues for Sanofi, and Sanofi does not expect a material impact on the consolidated financial statements. A.6. Covid-19 pandemic Covid-19, confirmed as a pandemic by the World Health Organization on March 11, 2020, has led to a global health crisis. Sanofi has assessed the impact of the uncertainties created by the pandemic. As of December 31, 2020, those uncertainties have not appreciably called into question the estimates and assumptions made by management (see Note A.3.). Sanofi will continue to reassess those estimates and assumptions as the situation evolves. Effect of the Covid-19 pandemic on the valuation of goodwill and other intangible assets In accordance with IAS 36 (Impairment of Assets), Sanofi conducts impairment tests on goodwill allocated to each of its cash generating units and on other intangible assets not yet available for use (such as capitalized in-process research and development) on an annual basis, regardless of whether there is an indication they might have become impaired (see Notes B.6. and D.5.). The impairment tests conducted as of December 31, 2020 found no indications of potential impairment. Sanofi also conducted impairment tests on certain intangible assets as a result of specific circumstances not directly related to the Covid-19 pandemic; the outcomes of those tests are described in Note D.5. Effect of the Covid-19 pandemic on accounts receivable As of December 31, 2020, Sanofi estimated the value of its accounts receivable using the expected loss method (see Note B.8.1.). Nothing was identified that would indicate a material increase in expected credit risk, especially as regards Sanofi’s principal customers (see Note D.34.). Effect of the Covid-19 pandemic on the liquidity position The Covid-19 pandemic has not had a negative impact on Sanofi’s liquidity position. Effect of the Covid-19 pandemic on the presentation of the income statement The effects of the Covid-19 pandemic are presented in the relevant line items of the income statement, according to the function or nature of the income or expense. A.7. Agreements relating to the recombinant Covid-19 vaccine candidate developed by Sanofi in collaboration with GSK On February 18, 2020, Sanofi and the US Department of Health and Human Services extended their research and development partnership to leverage Sanofi’s previous development work on a SARS vaccine to attempt to unlock a fast path forward for developing a Covid-19 vaccine. Under the terms of the collaboration, the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response within the US Department of Health and Human Services, is helping to fund the research and development undertaken by Sanofi. Sanofi has recognized the BARDA funding as a deduction from the research and development expenses incurred, in accordance with IAS 20 (Accounting for Government Grants and Disclosure of Government Assistance). The amount of government assistance received and expenses incurred in 2020 is immaterial. On April 14, 2020, Sanofi and GlaxoSmithKline (GSK) entered into a collaboration agreement to develop a recombinant Covid-19 vaccine candidate, with Sanofi contributing its S‑protein Covid-19 antigen (based on recombinant DNA technology) and GSK contributing its pandemic adjuvant technology. Sanofi is leading clinical development and the registration process for the vaccine. On July 31, 2020, the recombinant Covid-19 vaccine candidate developed by Sanofi in collaboration with GSK was selected by the US government’s Operation Warp Speed (OWS) program. Under the OWS, the US government is providing funds to support further development of the vaccine, including clinical trials and scaling-up of manufacturing capacity. The agreement also provides for the supply of 100 million doses of the vaccine, with payment due at the time vaccine doses are provided. Sanofi has recognized the funding received from the US government as a deduction from (i) the development expenses incurred or (ii) the acquisition cost of property, plant and equipment acquired, in accordance with IAS 20 (Accounting for Government Grants and Disclosure of Government Assistance). As regards delivery of the 100 million vaccine doses, Sanofi considers this to be a contract with a customer, to be accounted for in accordance with IFRS 15 (Revenue from Contracts with Customers). In September 2020, Sanofi and GSK signed pre-order contracts with the Canadian and UK governments and with the European Union for doses of the vaccine candidate. As of the date of signature, those contracts do not constitute a firm commitment to purchase since the governments and the EU can decide whether or not to proceed with their purchase based on the results of the clinical trial. If the pre-orders are confirmed, the amounts received by Sanofi on the date of signature of the pre-order contracts will be deducted from the amount due in respect of the firm order for the vaccines. In accordance with IFRS 15 (see Note B.13.1.), Sanofi recognizes revenue when control over the product is transferred to the customer (for vaccines, transfer of control is usually determined by reference to the terms of release and acceptance of batches of vaccine). The total amount received by Sanofi on signature of the vaccine pre-order contracts was €252 million. In accordance with IFRS 15, those payments are customer contract liabilities (i.e. an obligation for the entity to supply goods to a customer, for which consideration has been received from the customer). They are presented within “Customer contract liabilities” in the balance sheet (see Note D.19.5.), and within “Net change in other current assets and other current liabilities” in the statement of cash flows. On December 11, 2020, Sanofi and GSK published interim clinical trial results showing an immune response comparable to patients who recovered from Covid-19 in adults aged 18 to 49 years, but an insufficient response in older adults. The two companies reaffirmed their intention to ongoing development of the vaccine candidate but decided to initiate a Phase IIb study with an improved antigen formulation in the first quarter of 2021 in order to provide high-level immune response across all age groups. As of December 31, 2020 this new stage in the development of the vaccine candidate had not altered the funding commitments made by the US government, or the pre-orders placed by Canada, the UK and the EU.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2020
Corporate Information And Statement Of IFRS Compliance [Abstract]
Summary of significant accounting policies	Summary of significant accounting policiesBasis of consolidation In accordance with IFRS 10 (Consolidated Financial Statements), the consolidated financial statements of Sanofi include the financial statements of entities that Sanofi controls directly or indirectly, regardless of the level of the equity interest in those entities. An entity is controlled when Sanofi has power over the entity, exposure or rights to variable returns from its involvement with the entity, and the ability to affect those returns through its power over the entity. In determining whether control exists, potential voting rights must be taken into account if those rights are substantive, in other words they can be exercised on a timely basis when decisions about the relevant activities of the entity are to be taken. Entities consolidated by Sanofi are referred to as “subsidiaries”. Entities that Sanofi controls by means other than voting rights are referred to as “consolidated structured entities”. In accordance with IFRS 11 (Joint Arrangements), Sanofi classifies its joint arrangements (i.e. arrangements in which Sanofi exercises joint control with one or more other parties) either as a joint operation or a joint venture. In the case of a joint operation, Sanofi recognizes the assets and liabilities of the operation in proportion to its rights and obligations relating to those assets and liabilities. Joint ventures are accounted for using the equity method. Sanofi exercises joint control over a joint arrangement when decisions relating to the relevant activities of the arrangement require the unanimous consent of Sanofi and the other parties with whom control is shared. Sanofi exercises significant influence over an entity when it has the power to participate in the financial and operating policy decisions of that entity, but does not have the power to exercise control or joint control over those policies. In accordance with IAS 28 (Investments in Associates and Joint Ventures), the equity method is used to account for joint ventures (i.e. entities over which Sanofi exercises joint control) and for associates (i.e. entities over which Sanofi exercises significant influence). Under the equity method, the investment is initially recognized at cost, and subsequently adjusted to reflect changes in the net assets of the associate or joint venture. IAS 28 does not specify the treatment to be adopted on first-time application of the equity method to an investee following a step acquisition. Consequently, by reference to paragraph 10 of IAS 28, Sanofi has opted to apply the cost method, whereby the carrying amount of the investment represents the sum of the historical cost amounts for each step in the acquisition. As of the date on which the equity method is first applied, goodwill (which is included in the carrying amount of the investment) is determined for each acquisition step. The same applies to subsequent increases in the percentage interest in the equity-accounted investment. When the criteria of IFRS 5 are met, Sanofi recognizes the equity interest within the balance sheet line item Assets held for sale or exchange . The equity method is not applied to equity interests that are classified as held-for-sale assets. Transactions between consolidated companies are eliminated, as are intragroup profits. A list of the principal companies included in the consolidation in 2020 is presented in Note F. B.2.1. Accounting for foreign currency transactions in the financial statements of consolidated entities Non-current assets (other than receivables) and inventories acquired in foreign currencies are translated into the functional currency using the exchange rate prevailing at the acquisition date. Monetary assets and liabilities denominated in foreign currencies are translated using the exchange rate prevailing at the end of the reporting period. The gains and losses resulting from foreign currency translation are recorded in the income statement. However, foreign exchange gains and losses arising from the translation of advances between consolidated subsidiaries for which settlement is neither planned nor likely to occur in the foreseeable future are recognized in equity, in the line item Change in currency translation differences . B.2.2. Foreign currency translation of the financial statements of foreign entities Sanofi presents its consolidated financial statements in euros (€). In accordance with IAS 21 (The Effects of Changes in Foreign Exchange Rates), each subsidiary accounts for its transactions in the currency that is most representative of its economic environment (the functional currency). All assets and liabilities are translated into euros using the exchange rate of the subsidiary’s functional currency prevailing at the end of the reporting period. Income statements are translated using a weighted average exchange rate for the period, except in the case of foreign subsidiaries in a hyperinflationary economy. The resulting currency translation difference is recognized as a separate component of equity in the consolidated statement of comprehensive income, and is recognized in the income statement only when the subsidiary is sold or is wholly or partially liquidated. B.3.1. Accounting for business combinations, transactions with non-controlling interests and loss of control Business combinations are accounted for in accordance with IFRS 3 (Business Combinations) and IFRS 10 (Consolidated Financial Statements). Business combinations are accounted for using the acquisition method. Under this method, the acquiree’s identifiable assets and liabilities that satisfy the recognition criteria of IFRS 3 (Business Combinations) are measured initially at their fair values at the date of acquisition, except for (i) non-current assets classified as held for sale (which are measured at fair value less costs to sell) and (ii) assets and liabilities that fall within the scope of IAS 12 (Income Taxes) and IAS 19 (Employee Benefits). Restructuring liabilities are recognized as a liability of the acquiree only if the acquiree has an obligation as of the acquisition date to carry out the restructuring. The principal accounting rules applicable to business combinations and transactions with non-controlling interests include: • Acquisition-related costs are recognized as an expense on the acquisition date, as a component of Operating income . • Contingent consideration is recognized in equity if the contingent payment is settled by delivery of a fixed number of the acquirer’s equity instruments; otherwise, it is recognized in Liabilities related to business combinations . Contingent consideration is recognized at fair value at the acquisition date irrespective of the probability of payment. If the contingent consideration was originally recognized as a financial liability, subsequent adjustments to the liability are recognized in profit or loss in the line item Fair value remeasurement of contingent consideration , unless the adjustment is made within the twelve months following the acquisition date and relates to facts and circumstances existing as of that date. • Goodwill may be calculated on the basis of either (i) the entire fair value of the acquiree, or (ii) a share of the fair value of the acquiree proportionate to the interest acquired. This option is elected for each acquisition individually. Purchase price allocations are performed under the responsibility of management, with assistance from an independent valuer in the case of major acquisitions. IFRS 3 does not specify an accounting treatment for contingent consideration arising from a business combination made by an entity prior to the acquisition of control in that entity and carried as a liability in the acquired entity’s balance sheet. The accounting treatment applied by Sanofi to such a liability is to measure it at fair value as of the acquisition date and to report it in the line item Liabilities related to business combinations and to non-controlling interests , with subsequent remeasurements recognized in profit or loss. This treatment is consistent with the accounting applied to contingent consideration in the books of the acquirer. B.3.2. Goodwill The excess of the cost of an acquisition over Sanofi’s interest in the fair value of the identifiable assets and liabilities of the acquiree is recognized as goodwill at the date of the business combination. Goodwill arising on the acquisition of subsidiaries is shown in a separate balance sheet line item, whereas goodwill arising on the acquisition of investments accounted for using the equity method is recorded in Investments accounted for using the equity method . Goodwill arising on foreign operations is expressed in the functional currency of the country concerned and translated into euros using the exchange rate prevailing at the end of the reporting period. In accordance with IAS 36 (Impairment of Assets), goodwill is carried at cost less accumulated impairment (see Note B.6.). Goodwill is tested for impairment annually and whenever events or circumstances indicate that impairment might exist. Such events or circumstances include significant changes more likely than not to have an other-than-temporary impact on the substance of the original investment. Other intangible assets are initially measured at acquisition cost or production cost, including any directly attributable costs of preparing the asset for its intended use, or (in the case of assets acquired in a business combination) at fair value as of the date of the business combination. Intangible assets are amortized on a straight line basis over their useful lives. The useful lives of other intangible assets are reviewed at the end of each reporting period. The effect of any adjustment to useful lives is recognized prospectively as a change in accounting estimate. Amortization of other intangible assets is recognized in the income statement within Amortization of intangible assets except for amortization charged against (i) acquired or internally-developed software and (ii) other rights of an industrial or operational nature, which is recognized in the relevant classification of expense by function. Sanofi does not own any intangible assets with an indefinite useful life, other than goodwill. Intangible assets (other than goodwill) are carried at cost less accumulated amortization and accumulated impairment, if any, in accordance with IAS 36 (see Note B.6.). B.4.1. Research and development not acquired in a business combination Internally generated research and development Under IAS 38, research expenses are recognized in profit or loss when incurred. Internally generated development expenses are recognized as an intangible asset if, and only if, all the following six criteria can be demonstrated: (a) the technical feasibility of completing the development project; (b) Sanofi’s intention to complete the project; (c) Sanofi’s ability to use the project; (d) the probability that the project will generate future economic benefits; (e) the availability of adequate technical, financial and other resources to complete the project; and (f) the ability to measure the development expenditure reliably. Due to the risks and uncertainties relating to regulatory approval and to the research and development process, the six criteria for capitalization are usually considered not to have been met until the product has obtained marketing approval from the regulatory authorities. Consequently, internally generated development expenses arising before marketing approval has been obtained, mainly the cost of clinical trials, are generally expensed as incurred within Research and development expenses . Some industrial development expenses (such as those incurred in developing a second-generation synthesis process) are incurred after marketing approval has been obtained, in order to improve the industrial process for an active ingredient. To the extent that the six IAS 38 criteria are considered as having been met, such expenses are recognized as an asset in the balance sheet within Other intangible assets as incurred. Similarly, some clinical trials, for example those undertaken to obtain a geographical extension for a molecule that has already obtained marketing approval in a major market, may in certain circumstances meet the six capitalization criteria under IAS 38, in which case the related expenses are recognized as an asset in the balance sheet within Other intangible assets . Separately acquired research and development Payments for separately acquired research and development are capitalized within Other intangible assets provided that they meet the definition of an intangible asset: a resource that is (i) controlled by Sanofi, (ii) expected to provide future economic benefits for Sanofi, and (iii) identifiable (i.e. it is either separable or arises from contractual or legal rights). Under paragraph 25 of IAS 38, the first condition for capitalization (the probability that the expected future economic benefits from the asset will flow to the entity) is considered to be satisfied for separately acquired research and development. Consequently, upfront and milestone payments to third parties related to pharmaceutical products for which marketing approval has not yet been obtained are recognized as intangible assets, and amortized on a straight line basis over their useful lives beginning when marketing approval is obtained. Payments under research and development arrangements relating to access to technology or to databases, and payments made to purchase generics dossiers, are also capitalized, and amortized over the useful life of the intangible asset. Subcontracting arrangements, payments for research and development services, and continuous payments under research and development collaborations which are unrelated to the outcome of that collaboration, are expensed over the service term. B.4.2. Other intangible assets not acquired in a business combination Licenses other than those related to pharmaceutical products and research projects, in particular software licenses, are capitalized at acquisition cost, including any directly attributable cost of preparing the software for its intended use. Software licenses are amortized on a straight line basis over their useful lives for Sanofi ( three Internally generated costs incurred to develop or upgrade software are capitalized if the IAS 38 recognition criteria are satisfied, and amortized on a straight line basis over the useful life of the software from the date on which the software is ready for use. B.4.3. Other intangible assets acquired in a business combination Other intangible assets acquired in a business combination which relate to in-process research and development and currently marketed products and are reliably measurable are identified separately from goodwill, measured at fair value, and capitalized within Other intangible assets in accordance with IFRS 3 (Business Combinations) and IAS 38 (Intangible Assets). The related deferred tax liability is also recognized if a deductible or taxable temporary difference exists. In-process research and development acquired in a business combination is amortized on a straight line basis over its useful life from the date of receipt of marketing approval. Rights to products currently marketed by Sanofi are amortized on a straight line basis over their useful lives, determined on the basis of cash flow forecasts which take into account the patent protection period of the marketed product. B.5.1. Property, plant and equipment owned Property, plant and equipment is initially measured and recognized at acquisition cost, including any directly attributable cost of preparing the asset for its intended use, or (in the case of assets acquired in a business combination) at fair value as of the date of the business combination. The component-based approach to accounting for property, plant and equipment is applied. Under this approach, each component of an item of property, plant and equipment with a cost which is significant in relation to the total cost of the item and which has a different useful life from the other components must be depreciated separately. After initial measurement, property, plant and equipment is carried at cost less accumulated depreciation and impairment, except for land which is carried at cost less impairment. Subsequent costs are not recognized as assets unless (i) it is probable that future economic benefits associated with those costs will flow to Sanofi and (ii) the costs can be measured reliably. Borrowing costs attributable to the financing of items of property, plant and equipment, and incurred during the construction period, are capitalized as part of the acquisition cost of the item. Government grants relating to property, plant and equipment are deducted from the acquisition cost of the asset to which they relate. The depreciable amount of items of property, plant and equipment, net of any residual value, is depreciated on a straight line basis over the useful life of the asset. The useful life of an asset is usually equivalent to its economic life. The customary useful lives of property, plant and equipment are as follows: Buildings 15 to 40 years Fixtures 10 to 20 years Machinery and equipment 5 to 15 years Other 3 to 15 years Useful lives and residual values of property, plant and equipment are reviewed annually. The effect of any adjustment to useful lives or residual values is recognized prospectively as a change in accounting estimate. Depreciation of property, plant and equipment is recognized as an expense in the income statement, in the relevant classification of expense by function. B.5.2. Property, plant and equipment leased Effective from January 1, 2019 leases contracted by Sanofi have been accounted for in accordance with IFRS 16 (Leases). Sanofi recognizes a right-of-use asset and a lease liability for all of its lease contracts, except for (i) leases relating to low-value assets and (ii) short-term leases (12 months or less). Payments made in respect of leases not recognized on the balance sheet are recognized as an operating expense on a straight line basis over the lease term. On commencement of a lease, the liability for future lease payments is discounted at the incremental borrowing rate, which is a risk-free rate adjusted to reflect the specific risk profile of each Sanofi entity. Because lease payments are spread over the lease term, Sanofi applies a discount rate based on the duration of those payments. The payments used to determine the liability for future lease payments exclude non-lease components, but include fixed payments that Sanofi expects to make to the lessor over the estimated lease term. After commencement of the lease, the liability for future lease payments is reduced by the amount of the lease payments made, and increased to reflect interest on the liability. In the event of a reassessment or modification of future lease payments, the lease liability is remeasured. The right-of-use asset - which is initially measured at cost including direct costs of the lessee, prepayments made at or prior to the commencement date, less lease incentives received and restoration costs - is depreciated on a straight line basis over the lease term, and tested for impairment as required. Sanofi recognizes deferred taxes in respect of right-of-use assets and lease liabilities. Leasehold improvements are depreciated over their economic life, which is capped at the lease term as determined under IFRS 16. B.6.1. Impairment of property, plant and equipment and intangible assets In accordance with IAS 36 (Impairment of Assets), assets that generate separate cash flows and assets included in cash-generating units (CGUs) are assessed for impairment when events or changes in circumstances indicate that the asset or CGU may be impaired. A CGU is the smallest identifiable group of assets that generates cash inflows that are largely independent of the cash inflows from other assets or groups of assets. Under IAS 36, each CGU or group of CGUs to which goodwill is allocated must (i) represent the lowest level within the entity at which the goodwill is monitored for internal management purposes, and (ii) not be larger than an operating segment determined in accordance with IFRS 8 (Operating Segments), before application of the IFRS 8 aggregation criteria (see Note B.26.). Quantitative and qualitative indications of impairment (primarily relating to the status of the research and development portfolio, pharmacovigilance, patent litigation, and the launch of competing products) are reviewed at the end of each reporting period. If there is any internal or external indication of impairment, Sanofi estimates the recoverable amount of the asset or CGU. Other intangible assets not yet available for use (such as capitalized in-process research and development), and CGUs or groups of CGUs that include goodwill, are tested for impairment annually whether or not there is any indication of impairment, and more frequently if any event or circumstance indicates that they might be impaired. Such assets are not amortized. When there is an internal or external indication of impairment, Sanofi estimates the recoverable amount of the asset and recognizes an impairment loss if the carrying amount of the asset exceeds its recoverable amount. The recoverable amount of the asset is the higher of its fair value less costs to sell or its value in use. To determine value in use, Sanofi uses estimates of future cash flows generated by the asset or CGU, prepared using the same methods as those used in the initial measurement of the asset or CGU on the basis of medium-term strategic plans. In the case of goodwill, estimates of future cash flows are based on a five-year strategic plan, an extrapolation of the cash flows over a further five-year period, and a terminal value. In the case of other intangible assets, the period used is based on the economic life of the asset. Estimated cash flows are discounted at long-term market interest rates that reflect the best estimate by Sanofi of the time value of money, the risks specific to the asset or CGU, and economic conditions in the geographical regions in which the business activity associated with the asset or CGU is located. Certain assets and liabilities that are not directly attributable to a specific CGU are allocated between CGUs on a basis that is reasonable, and consistent with the allocation of the corresponding goodwill. Impairment losses arising on property, plant and equipment, on software and on certain rights are recognized in the relevant classification of expense by function. Impairment losses arising on other intangible assets are recognized within Impairment of intangible assets in the income statement. B.6.2. Impairment of investments accounted for using the equity method In accordance with IAS 28 (Investments in Associates and Joint Ventures), Sanofi determines whether investments accounted for using the equity method may be impaired based on indicators such as default in contractual payments, significant financial difficulties, probability of bankruptcy, or a prolonged or significant decline in quoted market price. If an investment is impaired, the amount of the impairment loss is determined by applying IAS 36 (see Note B.6.1.) and recognized in Share of profit/(loss) from investments accounted for using the equity method . B.6.3. Reversals of impairment losses charged against property, plant and equipment, intangible assets, and investments accounted for using the equity method At the end of each reporting period, Sanofi assesses whether events or changes in circumstances indicate that an impairment loss recognized in a prior period in respect of an asset (other than goodwill) or an investment accounted for using the equity method can be reversed. If this is the case, and the recoverable amount as determined based on the revised estimates exceeds the carrying amount of the asset, Sanofi reverses the impairment loss only to the extent of the carrying amount that would have been determined had no impairment loss been recognized for the asset. Reversals of impairment losses in respect of other intangible assets are recognized within the income statement line item Impairment of intangible assets , while reversals of impairment losses in respect of investments accounted for using the equity method are recognized within the income statement line item Share of profit/(loss) from investments accounted for using the equity method . Impairment losses taken against goodwill are never reversed, unless the goodwill is part of the carrying amount of an investment accounted for using the equity method. In accordance with IFRS 5 (Non-Current Assets Held for Sale and Discontinued Operations), non-current assets and groups of assets are classified as held for sale in the balance sheet if their carrying amount will be recovered principally through a sale transaction rather than through continuing use. Within the meaning of IFRS 5, the term “sale” also includes exchanges for other assets. Non-current assets or asset groups held for sale must be available for immediate sale in their present condition, subject only to terms that are usual and customary for sales of such assets, and a sale must be highly probable. Criteria used to determine whether a sale is highly probable include: • the appropriate level of management must be committed to a plan to sell; • an active program to locate a buyer and complete the plan must have been initiated; • the asset must be actively marketed for sale at a price that is reasonable in relation to its current fair value; • completion of the sale should be foreseeable within the twelve months following the date of reclassification to Assets held for sale or exchange ; and • actions required to complete the plan should indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Before initial reclassification of the non-current asset (or asset group) to Assets held for sale or exchange , the carrying amounts of the asset (or of all the assets and liabilities in the asset group) must be measured in accordance with the applicable standards. Subsequent to reclassification to Assets held for sale or exchange , the non-current asset (or asset group) is measured at the lower of carrying amount or fair value less costs to sell, with any write-down recognized by means of an impairment loss. Once a non-current asset has been reclassified as held for sale or exchange, it is no longer depreciated or amortized. In a disposal of an equity interest leading to loss of control, all the assets and liabilities of the entity involved are classified as held-for-sale assets or liabilities within the balance sheet line items Assets held for sale or exchange or Liabilities related to assets held for sale or exchange , provided that the disposal satisfies the IFRS 5 classification criteria. The profit or loss generated by a held-for-sale asset group is reported in a separate line item in the income statement for the current period and for the comparative periods presented, provided that the asset group: • represents a separate major line of business or geographical area of operations; or, • is part of a single coordinated plan to dispose of a separate major line of business or geographical area of operations; or, • is a subsidiary acquired exclusively with a view to resale. In accordance with IFRS 10, transactions between companies that are held for sale or treated as discontinued operations and other consolidated companies are eliminated. Events or circumstances beyond Sanofi’s control may extend the period to complete the sale or exchange beyond one year without precluding classification of the asset (or disposal group) in Assets held for sale or exchange provided that there is sufficient evidence that Sanofi remains committed to the planned sale or exchange. Finally, in the event of changes to a plan of sale that requires an asset no longer to be classified as held for sale, IFRS 5 specifies the following treatment: • The assets and liabilities previously classified as held for sale are reclassified to the appropriate balance sheet line items, with no restatement of comparative periods. • Each asset is measured at the lower of (a) its carrying amount before the asset was reclassified as held for sale, adjusted for any depreciation, amortization or revaluation that would have been recognized if the asset had not been reclassified as held for sale, or (b) its recoverable amount at the date of reclassification. • The backlog of depreciation, amortization and impairment not recognized while non-current assets were classified as held for sale must be reported in the same income statement line item that was used to report impairment losses arising on initial reclassification of assets as held for sale and gains or losses arising on the sale of such assets. In the consolidated income statement, those impacts are reported within the line item Other gains and losses, and litigation . • The net income of a business previously classified as discontinued or as held for sale or exchange and reported on a separate line in the income statement must be reclassified and included in net income from continuing operations, for all periods presented. • In addition, segment information relating to the income statement and the statement of cash flows (acquisitions of non-current assets) must be disclosed in the notes to the financial statements in accordance with IFRS 8 (Operating Segments), and must also be restated for all prior periods presented. B.8.1. Non-derivative financial assets In accordance with IFRS 9 (Financial Instruments) and IAS 32 (Financial Instruments: Presentation), Sanofi has adopted the classification of non-derivative financial assets described below. The classification used depends on (i) the characteristics of the contractual cash flows (i.e. whether they represent interest or principal) and (ii) the business model for managing the asset applied at the time of initial recognition. Financial assets at fair value through other comprehensive income These mainly comprise: • quoted and unquoted equity investments that Sanofi does not hold for trading purposes and that management has designated at “fair value through other comprehensive income” on initial recognition. Gains and losses arising from changes in fair value are recognized in equity within the statement of comprehensive income in the period in which they occur. When such instruments are derecognized, the previously-recognized changes in fair value remain within Other comprehensive income , as does the gain or loss on divestment. Dividends received are recognized in profit or loss for the period, within the line item Financial income ; and • debt instruments whose contractual cash flows represent payments of interest or repayments of principal, and which are managed with a view to collecting cash flows and selling the asset. Gains and losses arising from changes in fair value are recognized in equity within the statement of comprehensive income in the period in which they occur. When such assets are derecognized, the cumulative gains and losses previously recognized in equity are reclassified to profit or loss for the period within the line items Financial income or Financial expenses . Financial assets at fair value through profit or loss These mainly comprise: • contingent consideration already carried in the books of an acquired entity or granted in connection with a business combination; • instruments whose contractual cash flows represent payments of interest and repayments of principal, which are managed with a view to selling the asset; • instruments that management has designated at “fair value through profit or loss” on initial recognition; and • quoted and unquoted equity investments: equity instruments that are not held for trading and which management did not designate at “fair value through other comprehensive income” on initial recognition, and instruments that do not meet the IFRS definition of “equity instruments”. Gains and losses arising from changes in fair value are recognized in profit or loss within the line items Financial income or Financial expenses . Dividends received are recognized in profit or loss for the period, within the line item Financial income . Fair value of equity investments in unquoted entities On initial recognition of an equity investment in an entity not quoted in an active market, the fair value

Principal alliances

Principal alliances	12 Months Ended
	Dec. 31, 2020
Related Party [Abstract]
Principal alliances	Principal alliances C.1. Alliance arrangements with Regeneron Pharmaceuticals, Inc. (Regeneron) Collaboration agreements on human therapeutic antibodies In November 2007, Sanofi and Regeneron signed two agreements (amended in November 2009) relating to human therapeutic antibodies: (i) the Discovery and Preclinical Development Agreement, and (ii) the License and Collaboration Agreement, relating to clinical development and commercialization. Under the License and Collaboration Agreement, Sanofi had an option to develop and commercialize antibodies discovered by Regeneron under the Discovery and Preclinical Development Agreement. Discovery and development Under the 2009 amended agreements, Sanofi funded the discovery and pre-clinical development of fully human therapeutic antibodies up to a maximum of $160 million per year through 2017. Because Sanofi decided not to exercise its option to extend the Discovery and Preclinical Development Agreement, that agreement expired on December 31, 2017. Upon Sanofi’s exercise of an option on an antibody under the Discovery and Preclinical Development Agreement, the antibody became a Licensed Product under the License and Collaboration Agreement, pursuant to which Sanofi and Regeneron co-develop the antibody with Sanofi initially being wholly responsible for funding the development program. On receipt of the first positive Phase III trial results for any antibody being developed under the License and Collaboration Agreement, the subsequent Phase III costs for that antibody are split 80% Sanofi, 20% Regeneron. Amounts received from Regeneron under those arrangements are recognized by Sanofi as a reduction in the line item Research and development expenses . Co-development with Regeneron of the antibodies Dupixent ® , Kevzara ® and REGN3500 (SAR440340 - itepekimab) is ongoing under the License and Collaboration Agreement at this time. Once a product begins to be commercialized, and provided that the share of quarterly results under the agreement represents a profit, Sanofi is entitled to an additional portion of Regeneron’s profit-share (capped at 10% of Regeneron’s share of quarterly profits) until Regeneron has paid 50% of the cumulative development costs incurred by the parties in the collaboration (see footnote g(ii) to the table provided in Note D.21.1., "Off balance sheet commitments relating to operating activities"). On the later of (i) 24 months before the scheduled launch date or (ii) the first positive Phase III trial results, Sanofi and Regeneron share the commercial expenses of the antibodies co-developed under the License and Collaboration Agreement. Commercialization Sanofi is the lead party with respect to the commercialization of all co-developed antibodies, and Regeneron has certain option rights to co-promote the antibodies. Sanofi recognizes all sales of the antibodies. Profits and losses arising from commercial operations in the United States are split 50/50. Outside the United States, Sanofi is entitled to between 55% and 65% of profits depending on sales of the antibodies, and bears 55% of any losses. The share of profits and losses due to or from Regeneron under the agreement is recognized within the line items Other operating income or Other operating expenses , which are components of Operating income . In addition, Regeneron is entitled to receive payments of up to $250 million contingent on the attainment of specified levels of aggregate sales on all antibodies outside the United States, on a rolling twelve-month basis. As of September 30, 2020, sales of antibodies outside the United States exceeded $1.0 billion on a rolling twelve-month basis, triggering a payment by Sanofi to Regeneron of $50.0 million for the first sales milestone. Amendments to the collaboration agreements In January 2018, Sanofi and Regeneron signed a set of amendments to their collaboration agreements, including an amendment that allowed for the funding of additional programs on Dupixent ® and REGN3500 (SAR440340) with an intended focus on extending the current range of indications, finding new indications, and improving co-morbidity between multiple pathologies. Effective April 1, 2020, Sanofi and Regeneron signed a Cross License and Commercialization Agreement for Praluent ® , whereby Sanofi obtained sole ex-US rights to Praluent ® , and Regeneron obtained sole US rights to Praluent ® along with a right to 5% royalties on Sanofi’s sales of Praluent ® outside the United States. Each party is solely responsible for the development, manufacturing and commercialization of Praluent ® in their respective territories. Although each company has responsibility for supplying Praluent ® in its respective territory, the companies have entered into agreements to support manufacturing needs for each other. Sanofi and Regeneron continue to investigate restructuring their collaboration for Kevzara ® . The Zaltrap ® Manufacturing and Supply Agreement terminates on December 31, 2021. Regeneron and Sanofi are discussing a potential extension of such agreement. The terms of the collaboration relating to Dupixent ® (dupilumab) and to SAR440340 (REGN3500) are unchanged. Immuno-oncology (IO) collaboration agreements On July 1, 2015, Sanofi and Regeneron signed two agreements - the IO Discovery and Development Agreement and the IO License and Collaboration Agreement (IO LCA) - relating to new antibody cancer treatments in the field of immuno-oncology. As part of the agreements, Sanofi made an upfront payment of $640 million to Regeneron. The two companies agreed to invest approximately $1 billion from discovery through proof of concept (POC) development (usually a Phase IIa study) of monotherapy and novel combinations of immuno-oncology antibody candidates to be funded 25% by Regeneron ($250 million) and 75% by Sanofi ($750 million). The two companies also agreed to reallocate $75 million (spread over three years) to immuno-oncology antibody research and development from Sanofi’s $160 million annual contribution under their existing antibody Discovery and Preclinical Development Agreement. An Amended IO Discovery Agreement, effective from December 31, 2018, was signed on January 2, 2019. It narrows the scope of the existing discovery and development activities conducted by Regeneron ("IO Development Activities") under the original 2015 IO Discovery and Development Agreement to developing therapeutic bispecific antibodies targeting (i) BCMA and CD3 (the "BCMAxCD3 Program") and (ii) MUC16 and CD3 (the "MUC16xCD3 Program") through clinical proof-of-concept. Under the terms of the Amended IO Discovery Agreement, Sanofi paid Regeneron $462 million as consideration for (i) the termination of the 2015 IO Discovery Agreement, (ii) the prepayment for certain IO Development Activities regarding the BCMAxCD3 Program and the MUC16xCD3 Program, and (iii) the reimbursement of costs incurred by Regeneron under the 2015 IO Discovery Agreement during the fourth quarter of 2018. This gives Sanofi increased flexibility to advance its early-stage immuno-oncology pipeline independently, while Regeneron retains all rights to its other immuno-oncology discovery and development programs. The ongoing development and commercialization collaboration on Libtayo ® (cemiplimab) is unaffected by the amendments to the IO Discovery and Development Agreement. Upon establishment of POC, or when the allocated funding has been expended, whichever is earlier, Sanofi can exercise its opt-in rights to further develop and commercialize under the IO LCA the two candidates derived from the amended IO Discovery Agreement. Sanofi has decided to opt-out with respect to the MUC16xCD3 program. If Sanofi exercises its opt-in rights with respect to the BCMAxCD3 program, Sanofi will lead the development and global commercialization of the BCMAxCD3 candidate antibody and fund the development costs in full; Regeneron will refund 50% of those costs provided that the share of quarterly results under the IO LCA represents a profit, subject to a cap set at 10% of Regeneron’s profit-share. Libtayo ® (cemiplimab) Under the 2015 IO LCA as amended in January 2018, Sanofi and Regeneron committed funding of no more than $1,640 million, split on a 50/50 basis ($820 million per company), for the development of REGN2810 (cemiplimab, trademark Libtayo ® ), a PD-1 inhibitor antibody. Regeneron is responsible for the commercialization of Libtayo ® in the United States, and Sanofi in all other territories. Sanofi has exercised its option to co-commercialize Libtayo ® in the United States. The IO LCA also provided for a one-time milestone payment of $375 million by Sanofi to Regeneron in the event that sales of a PD-1 product and any other collaboration antibody sold for use in combination with a PD-1 product were to exceed, in the aggregate, $2 billion in any consecutive 12-month period. Under the IO LCA Sanofi and Regeneron share equally in profits and losses in connection with the commercialization of collaboration products, except that Sanofi is entitled to an additional share of profits capped at 10% of the share of Regeneron’s quarterly profits in order to reimburse Sanofi for up to 50% of the clinical development costs funded by Sanofi under the IO Discovery Agreement, as amended. In September 2018, the US Food and Drug Administration (FDA) approved Libtayo ® (cemiplimab) for the treatment of patients with metastatic cutaneous squamous cell carcinoma (CSCC) or locally advanced CSCC who are not candidates for curative surgery or curative radiation. Libtayo ® is a fully human monoclonal antibody targeting the immune checkpoint receptor PD-1 (programmed cell death protein-1) and is the first and only treatment specifically approved and available for advanced CSCC in the US. In July 2019, the European Medicines Agency (EMA) granted marketing authorization for Libtayo ® for patients with metastatic or locally advanced CSCC who are not candidates for surgery. In addition to advanced CSCC, clinical trials are ongoing to investigate cemiplimab in non-small cell lung cancer, basal cell carcinoma, cervical cancer, head and neck squamous cell carcinoma, melanoma, colorectal cancer, prostate cancer, multiple myeloma, Hodgkin’s disease and non-Hodgkin lymphoma. Those potential indications are still investigational, and the safety and efficacy of Libtayo ® have not been evaluated by any regulatory authority for any of them. Investor agreement In January 2014, Sanofi and Regeneron amended the investor agreement that had existed between the two companies since 2007. Under the terms of the amendment, Sanofi accepted various restrictions. Sanofi is bound by certain “standstill” provisions, which contractually prohibit Sanofi from seeking to directly or indirectly exert control of Regeneron or acquiring more than 30% of Regeneron’s capital stock (consisting of the outstanding shares of common stock and the shares of Class A stock). This prohibition remains in place until the earlier of (i) the later of the fifth anniversaries of the expiration or earlier termination of the Zaltrap ® collaboration agreement with Regeneron (related to the development and commercialization of Zaltrap ® ) or the collaboration agreement with Regeneron on monoclonal antibodies (see “Collaboration agreements on human therapeutic antibodies” above), each as amended and (ii) other specified events. Sanofi also agreed to vote as recommended by Regeneron’s Board of Directors, except that it could elect to vote proportionally with the votes cast by all of Regeneron’s other shareholders with respect to certain change-of-control transactions, and to vote in its sole discretion with respect to liquidation or dissolution, stock issuances equal to or exceeding 20% of the outstanding shares or voting rights of Regeneron’s Class A Stock and Common Stock (taken together), and new equity compensation plans or amendments if not materially consistent with Regeneron’s historical equity compensation practices. As soon as it had passed the threshold of 20% ownership of the capital stock, Sanofi exercised its right to designate an independent director, who was appointed to the Board of Directors of Regeneron. Sanofi began to account for its interest in Regeneron using the equity method in April 2014. On the conditions set out in the Amended Investor Agreement of January 2014, Sanofi’s right to designate a Regeneron board member was contingent on Sanofi maintaining its percentage share of Regeneron’s outstanding capital stock (measured on a quarterly basis) at a level no lower than the highest percentage level previously achieved, with the maximum requirement capped at 25%. In addition, Sanofi’s interest in Regeneron was subject to a lock-up clause. Those restrictions were amended by the letter agreement of January 2018 (see below). At Sanofi’s request, pursuant to the Amended Investor Agreement, Regeneron appointed a new independent director, N. Anthony “Tony” Coles, M.D. to its Board of Directors in January 2017 as a Sanofi designee. The Amended Investor Agreement also gave Sanofi the right to receive certain reasonable information as might be agreed upon by the parties and which was a factor in Sanofi’s ability to account for its investment in Regeneron using the equity method of accounting under IFRS. In January 2018, Sanofi and Regeneron announced (i) amendments to their collaboration agreements on human therapeutic antibodies; (ii) amendments to the IO LCA on the development of cemiplimab (REGN2810); and (iii) a limited waiver and amendment of the Amended Investor Agreement (the Amended and Restated Investor Agreement) pursuant to a letter agreement (the “2018 Letter Agreement”). Pursuant to the 2018 Letter Agreement, Regeneron agreed to grant a limited waiver of the lock-up clause and the obligation to maintain the “Highest Percentage Threshold” in the Amended and Restated Investor Agreement between the companies, so that Sanofi could elect to sell a small percentage of the Regeneron common stock it owns to fund a portion of the cemiplimab and dupilumab development expansion. This waiver allowed Sanofi to sell up to an aggregate of 1.4 million shares of Regeneron common stock to Regeneron in private transactions through the end of 2020. If Regeneron decided not to purchase the shares, Sanofi would be allowed to sell those shares on the open market, subject to certain volume and timing limitations. Upon expiration of the limited waiver under the 2018 Letter Agreement, the Amended and Restated Investor Agreement would be amended to define “Highest Percentage Threshold” as the lower of (i) 25% of Regeneron outstanding shares of Class A Stock and Common Stock (taken together) and (ii) the higher of (a) Sanofi’s percentage ownership of Class A Stock and Common Stock (taken together) on such termination date and (b) the highest percentage ownership of Regeneron outstanding shares of Class A Stock and Common Stock (taken together) Sanofi attains following such termination date. As of December 31, 2019, Sanofi had sold Regeneron 530,172 shares of Regeneron stock out of the 1.4 million shares covered by the 2018 Letter Agreement. In December 2019, Sanofi announced that on expiration of the lock-up term and as defined in the Amended and Restated Investor Agreement as amended by the 2018 Letter Agreement (i.e. in principle after December 20, 2020), Sanofi could dispose of its entire interest in Regeneron or of some of the shares of common stock held, on any single occasion or from time to time, via public offering or market transactions or a private sale, using derivatives or other means, at prices and on other terms acceptable to Sanofi depending on Sanofi’s capital allocation priorities and alternative investment opportunities, market conditions, the price of Regeneron common stock, and any other factors judged relevant by Sanofi with respect to its investment in Regeneron. Those provisions were to be implemented in accordance with the Amended and Restated Investor Agreement as amended by the 2018 Letter Agreement, including the restrictions contained in Section 5 of the Amended and Restated Investor Agreement. On May 29, 2020, Sanofi announced the closing of its sale of 13 million shares of Regeneron common stock in a registered offering and a private sale to Regeneron. As a result, Sanofi sold its entire equity investment in Regeneron, except for 400,000 Regeneron shares retained by Sanofi to partially fund investments allocated to the development programs for cemiplimab and dupilumab pursuant to the 2018 Letter Agreement (see Note D.1.). On May 29, 2020, an amendment to the Investor Agreement became effective, which stipulates inter alia that (i) the “standstill” provisions in the Investor Agreement, which contractually prohibit Sanofi from seeking to directly or indirectly exert control of Regeneron, will continue to apply; (ii) Sanofi will no longer have the right to designate an independent board member on the Regeneron Board of Directors (but with no effect on the term of office of the current Sanofi designee); (iii) the voting commitments contained in the Investor Agreement will continue to apply to shares held by Sanofi. The registered offering and share repurchase will not affect the ongoing collaboration between Sanofi and Regeneron: the two companies have had a successful and long-standing clinical and commercial collaboration dating back to 2003 that has resulted in five approved treatments to date, with additional candidates currently in clinical development. As of December 31, 2020, Sanofi had sold an additional 120,234 shares of Regeneron stock out of the 400,000 shares retained as of May 29, 2020, per above, and consequently still holds 279,766 shares of Regeneron stock. C.2. Alliance arrangements with Bristol-Myers Squibb (BMS) Two of Sanofi’s leading products were jointly developed with BMS: the anti-hypertensive agent irbesartan (Aprovel ® /Avapro ® /Karvea ® ) and the anti-atherothrombosis treatment clopidogrel bisulfate (Plavix ® /Iscover ® ). On September 27, 2012, Sanofi and BMS signed an agreement relating to their alliance following the loss of exclusivity of Plavix ® and Avapro ® /Avalide ® in many major markets. Under the terms of this agreement, effective January 1, 2013, BMS returned to Sanofi its rights to Plavix ® and Avapro ® /Avalide ® in all markets worldwide with the exception of Plavix ® in the United States and Puerto Rico (“Territory B”), giving Sanofi sole control and freedom to operate commercially in respect of those products. In exchange, BMS received royalty payments on Sanofi’s sales of branded and unbranded Plavix ® and Avapro ® /Avalide ® worldwide (except for Plavix ® in Territory B) until 2018, and also received a payment of $200 million from Sanofi in December 2018, part of which is for buying out the non-controlling interests (see Note D.18.). Rights to Plavix ® in Territory B remained unchanged and continued to be governed by the terms of the original agreement until February 28, 2020. In all of the territories managed by Sanofi (including the United States and Puerto Rico for Avapro ® /Avalide ® ) as defined in the new agreement, Sanofi recognized in its consolidated financial statements the revenue and expenses generated by its own operations. Since January 2019 onwards, there has no longer been any share of profits reverting to BMS (previously presented within Net income attributable to non-controlling interests in the income statement). In Territory B for Plavix ® , which was managed by BMS, the Plavix ® business was conducted through the Territory B partnerships, which were jointly owned by BMS and Sanofi. Sanofi recognized its share of profits and losses within the line item Share of profit/(loss) from investments accounted for using the equity method . On February 28, 2020, Sanofi purchased all BMS’s interests (50.1%) in each of the Territory B partnerships for a cumulative purchase price of $12 million. Following a transition period, Sanofi has been commercializing Plavix ® under its own label since July 1, 2020.

Changes in the scope of consoli

Changes in the scope of consolidation in 2020	12 Months Ended
	Dec. 31, 2020
Business Combinations 1 [Abstract]
Changes in the scope of consolidation in 2020	Presentation of the financial statementsChanges in the scope of consolidation in 2020 Acquisition of Principia On August 17, 2020, Sanofi and Principia Biopharma Inc. ("Principia"), a late-stage biopharmaceutical company focused on developing treatments for autoimmune diseases, entered into a definitive agreement under which Sanofi was to acquire all the outstanding shares of Principia for $100 per share. The transaction was approved unanimously by the Boards of Directors of Sanofi and Principia. Sanofi's acquisition of Principia was completed on September 28, 2020, with Sanofi holding the entire share capital of Principia upon expiration of the squeeze-out procedure. The provisional purchase price allocation, as presented in the table below, led to the recognition of goodwill of €913 million: (€ million) Fair value at acquisition date Intangible assets other than goodwill 2,534 Other current and non-current assets and liabilities (38) Cash and cash equivalents 186 Net deferred tax position (437) Net assets of Principia 2,245 Goodwill 913 Purchase price 3,158 Intangible assets other than goodwill mainly comprise: • rilzabrutinib (PRN 1008), a molecule undergoing clinical trials for various indications in immuno-inflammatory diseases and rare blood disorders; and • tolebrutinib (PRN 2246/SAR442168), a molecule currently undergoing clinical trials for the treatment of multiple sclerosis and other diseases of the central nervous system. Goodwill represents (i) the pipeline of future products in pre-clinical research and development; (ii) the capacity to draw on a specialized structure to refresh the existing product portfolio; and (iii) the competencies of Principia staff . The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes . Principia has no commercial operations, and has made a negative contribution of € 45 million to Sanofi’s consolidated net income since the acquisition date . Acquisition-related costs recognized in profit or loss in 2020 were recorded within the line item Other operating expenses , and amounted to € 13 million. The cash outflow on this acquisition amounted to €2,972 million , and was recorded in the line item Acquisitions of consolidated undertakings and investments accounted for using the equity method within the consolidated statement of cash flows . Acquisition of Synthorx On December 9, 2019, Sanofi and Synthorx Inc. (“Synthorx”), a clinical-stage biotechnology company focused on prolonging and improving the lives of people suffering from cancer and autoimmune disorders, entered into a definitive agreement under which Sanofi was to acquire all of the outstanding shares of Synthorx for $68 per share. The transaction was unanimously approved by both the Sanofi and Synthorx Boards of Directors. On December 23, 2019, Sanofi launched a public tender offer to acquire all of the outstanding ordinary shares of Synthorx for $68 per share in cash, without interest and net of any applicable withholding taxes. The acquisition of Synthorx was completed on January 23, 2020, with Sanofi holding the entire share capital of Synthorx upon expiration of the squeeze-out procedure . The final purchase price allocation, as presented in the table below, led to the recognition of goodwill of € 930 million : (€ million) Fair value at acquisition date Intangible assets other than goodwill 1,549 Other current and non-current assets and liabilities 36 Net deferred tax position (269) Net assets of Synthorx 1,316 Goodwill 930 Purchase price 2,246 Intangible assets other than goodwill mainly comprise THOR-707, a molecule currently in Phase I clinical trials that stimulates T lymphocytes, and as such has potential as a cancer immunotherapy. Goodwill represents (i) the pipeline of future products in pre-clinical research and development; (ii) the capacity to draw on a specialized structure to refresh the existing product portfolio; (iii) the competencies of Synthorx staff; (iv) benefits derived from the creation of new growth platforms; and (v) expected future synergies and other benefits from the combination of Synthorx and Sanofi. The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes. Synthorx has no commercial operations, and has made a negative contribution of € 106 million to Sanofi’s consolidated net income since the acquisition date. Acquisition-related costs were recognized in profit or loss mainly in the year ended December 31, 2019 within the line item Other operating expenses , and amounted to € 8 million . The cash outflow on this acquisition amounted to € 2,245 million , and was recorded in the line item Acquisitions of consolidated undertakings and investments accounted for using the equity method within the consolidated statement of cash flows . Transaction related to the equity-accounted investment in Regeneron From the beginning of April 2014, Sanofi accounted for its investment in Regeneron using the equity method. As from that date, in accordance with the Investor Agreement as amended in early 2014, Sanofi had the right to designate a member of the Regeneron Board of Directors. On May 29, 2020, Sanofi closed the transaction announced on May 25, 2020 involving the sale of its equity investment in Regeneron (with the exception of 400,000 shares), through (i) a registered public offering in the United States and internationally and (ii) a share repurchase by Regeneron. Sanofi sold 13 million shares of Regeneron common stock (of which 10.6 million were sold by Sanofi) through the public offering at a price of $515 per share, raising a total amount of $6,703 million; and Regeneron repurchased 9.8 million of its own shares of common stock directly from Sanofi for $5,000 million, at the offer price less a subscription discount ($509.85 per share). The total sale proceeds (before transaction-related costs) amounted to €10,575 million. At the same time, Sanofi as a result of this transaction lost the right to designate a member of the Regeneron Board of Directors under the amended Investor Agreement. Finally, as of May 29, 2020 Sanofi retained ownership of 400,000 Regeneron shares in order to continue to partially fund its commitments to invest in the development programs for cemiplimab (REGN2810) and dupilumab, in line with the 2018 Letter Agreement under which Sanofi is permitted to sell up to 1.4 million shares through the end of 2020. As of December 31, 2020, Sanofi had sold 779,320 Regeneron shares under that agreement. The number of Regeneron shares retained by Sanofi is 279,766 as of December 31, 2020 (see Note C.1.). Sanofi’s equity investment in Regeneron was accounted for by the equity method until May 29, 2020. As of that date, the carrying amount of the investment was €3,668 million; that amount was reversed out on closing of the transaction. Before tax effects, the gain on the divestment amounted to €7,382 million, including (i) a gain of €318 million arising on the currency translation reserve associated with Regeneron, which was taken to profit or loss in accordance with IAS 21; (ii) the deduction of transaction-related costs of €64 million; and (iii) a gain of €157 million on the remeasurement of the 400,000 retained shares at their quoted market price as of May 29, 2020 ($612.81). In accordance with IFRS 9 (Financial Instruments), the retained shares were classified in the “Equity instruments at fair value through other comprehensive income” category on the transaction date, at a value of €221 million (see Note D.7.). The tax charge arising on the transaction was €502 million. Given the material impact of this transaction, and to facilitate users’ understanding of the financial statements, the pre-tax gain on this transaction is presented as a separate line item in the consolidated income statement, Gain on Regeneron investment arising from the transaction of May 29, 2020 . The net cash inflow from the transaction was €10,370 million, which (for the reason cited above) is presented as a separate line item in the consolidated statement of cash flows, Net proceeds from sale of Regeneron shares on May 29, 2020. Sale of Seprafilm ® On November 27, 2019, Sanofi entered into a definitive agreement to sell Seprafilm ® to Baxter. The sale was completed on February 14, 2020. Sanofi recognized a pre-tax gain of €129 million. The impact of this sale, reflected in the line item Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax within the consolidated statement of cash flows, was a net cash inflow before tax of €311 million. D.2.1. Principal changes in the scope of consolidation in 2019 The impacts of the acquisitions carried out in 2019 are not material to the Sanofi consolidated financial statements, and Sanofi did not divest any material operations or companies during the year. Regeneron Pharmaceuticals, Inc. (Regeneron) Changes in the equity interest held by Sanofi in Regeneron during 2019 and 2018 are set forth below: (€ million) 2019 2018 Carrying amount (a) 3,342 3,055 Equity interest 21.2 % 21.7 % Acquisitions of shares — — Disposals of shares (b) 33 24 (a) See Note D.6. ® , Dupixent ® and REGN3500 (SAR440340) (see Note C.1.). As mentioned in Note D.1., following the sale of 22.8 million shares of Regeneron common stock on May 29, 2020, Sanofi ceased to exercise significant influence over Regeneron, as a result of which Sanofi's interest in Regeneron is no longer accounted for using the equity method (see Note D.6.). D.2.2. Principal changes in the scope of consolidation in 2018 Acquisition of Bioverativ Following a public tender offer, on March 8, 2018 Sanofi acquired the entire share capital of Bioverativ, a biotechnology company specializing in the development of treatments for hemophilia and other rare blood disorders, for a total consideration of $11.6 billion (€9.4 billion). The final purchase price allocation resulted in the recognition of goodwill amounting to €2,676 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 8,113 Inventories 145 Cash and cash equivalents 422 Other current and non-current assets and liabilities 16 True North Therapeutics contingent consideration liability (226) Net deferred tax position (1,792) Net assets of Bioverativ 6,678 Goodwill 2,676 Purchase price 9,354 The other intangible assets recognized mainly comprise the marketed hemophilia products Eloctate ® and Alprolix ® , and development projects relating to treatments for rare blood disorders. Goodwill represents (i) the pipeline of future products in early-stage research and development not identified individually at the acquisition date; (ii) the capacity to draw on a specialized structure to refresh the existing product portfolio; (iii) the competencies of Bioverativ staff; (iv) the benefits derived from the creation of new growth platforms; and (v) the expected future synergies and other benefits from the combination of Bioverativ and Sanofi. The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes . No material adjustment was required on completion of the final purchase price allocation. Acquisition of Ablynx On May 14, 2018, following a public tender offer, Sanofi acquired 95.60% of the share capital of Ablynx, a biopharmaceutical company specializing in the discovery and development of Nanobodies ® . On June 19, 2018, following the expiration of the squeeze-out procedure, Sanofi announced that it held the entire share capital of Ablynx, representing a total investment of €3,897 million. The final purchase price allocation resulted in the recognition of goodwill amounting to €1,360 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 2,409 Cash and cash equivalents 258 Other current and non-current assets and liabilities 131 Net deferred tax position (261) Net assets of Ablynx 2,537 Goodwill 1,360 Purchase price 3,897 The other intangible assets acquired mainly comprise rights to (i) Cablivi ® , a medicine for the treatment of adults who have experienced an episode of acquired thrombotic thrombocytopenic purpura (aTTP) and (ii) the exploitation of technology developed by Ablynx that uses camelid antibody fragments (Nanobodies ® ) to discover and identify multi-specific molecules targeting multiple diseases in various therapeutic fields. Goodwill represents the pipeline of future products in early-stage research and development not identified individually at the acquisition date, and the potential for those products to replace the existing product portfolio over the long term using resources and competencies specific to Ablynx, together with the expected future synergies and other benefits from the combination of Ablynx and Sanofi. The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes . No material adjustments were required further to the final purchase price allocation. Divestment of the European Generics business On September 30, 2018, Sanofi finalized the divestment of its European Generics business. Sanofi recognized a gain of €510 million before taxes. An analysis of the assets and liabilities divested is set forth below: (€ million) September 30, 2018 Assets Property, plant and equipment 120 Goodwill 913 Other intangible assets 75 Other non-current assets 1 Deferred tax assets 83 Inventories 129 Accounts receivable 107 Other current assets 40 Cash and cash equivalents 122 Total assets of the divested European Generics business 1,590 Liabilities Non-current provisions and other non-current liabilities 27 Deferred tax liabilities 14 Accounts payable 91 Other current liabilities 216 Short-term debt and current portion of long-term debt 46 Total liabilities of the divested European Generics business 394 The cash inflow on this divestment amounted to €1,598 million, and was recorded in the line item Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax within the consolidated statement of cash flows.

Principal changes in the scope

Principal changes in the scope of consolidation in 2019 and 2018	12 Months Ended
	Dec. 31, 2020
Business Combinations 1 [Abstract]
Changes in the scope of consolidation in 2019 and 2018	Presentation of the financial statementsChanges in the scope of consolidation in 2020 Acquisition of Principia On August 17, 2020, Sanofi and Principia Biopharma Inc. ("Principia"), a late-stage biopharmaceutical company focused on developing treatments for autoimmune diseases, entered into a definitive agreement under which Sanofi was to acquire all the outstanding shares of Principia for $100 per share. The transaction was approved unanimously by the Boards of Directors of Sanofi and Principia. Sanofi's acquisition of Principia was completed on September 28, 2020, with Sanofi holding the entire share capital of Principia upon expiration of the squeeze-out procedure. The provisional purchase price allocation, as presented in the table below, led to the recognition of goodwill of €913 million: (€ million) Fair value at acquisition date Intangible assets other than goodwill 2,534 Other current and non-current assets and liabilities (38) Cash and cash equivalents 186 Net deferred tax position (437) Net assets of Principia 2,245 Goodwill 913 Purchase price 3,158 Intangible assets other than goodwill mainly comprise: • rilzabrutinib (PRN 1008), a molecule undergoing clinical trials for various indications in immuno-inflammatory diseases and rare blood disorders; and • tolebrutinib (PRN 2246/SAR442168), a molecule currently undergoing clinical trials for the treatment of multiple sclerosis and other diseases of the central nervous system. Goodwill represents (i) the pipeline of future products in pre-clinical research and development; (ii) the capacity to draw on a specialized structure to refresh the existing product portfolio; and (iii) the competencies of Principia staff . The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes . Principia has no commercial operations, and has made a negative contribution of € 45 million to Sanofi’s consolidated net income since the acquisition date . Acquisition-related costs recognized in profit or loss in 2020 were recorded within the line item Other operating expenses , and amounted to € 13 million. The cash outflow on this acquisition amounted to €2,972 million , and was recorded in the line item Acquisitions of consolidated undertakings and investments accounted for using the equity method within the consolidated statement of cash flows . Acquisition of Synthorx On December 9, 2019, Sanofi and Synthorx Inc. (“Synthorx”), a clinical-stage biotechnology company focused on prolonging and improving the lives of people suffering from cancer and autoimmune disorders, entered into a definitive agreement under which Sanofi was to acquire all of the outstanding shares of Synthorx for $68 per share. The transaction was unanimously approved by both the Sanofi and Synthorx Boards of Directors. On December 23, 2019, Sanofi launched a public tender offer to acquire all of the outstanding ordinary shares of Synthorx for $68 per share in cash, without interest and net of any applicable withholding taxes. The acquisition of Synthorx was completed on January 23, 2020, with Sanofi holding the entire share capital of Synthorx upon expiration of the squeeze-out procedure . The final purchase price allocation, as presented in the table below, led to the recognition of goodwill of € 930 million : (€ million) Fair value at acquisition date Intangible assets other than goodwill 1,549 Other current and non-current assets and liabilities 36 Net deferred tax position (269) Net assets of Synthorx 1,316 Goodwill 930 Purchase price 2,246 Intangible assets other than goodwill mainly comprise THOR-707, a molecule currently in Phase I clinical trials that stimulates T lymphocytes, and as such has potential as a cancer immunotherapy. Goodwill represents (i) the pipeline of future products in pre-clinical research and development; (ii) the capacity to draw on a specialized structure to refresh the existing product portfolio; (iii) the competencies of Synthorx staff; (iv) benefits derived from the creation of new growth platforms; and (v) expected future synergies and other benefits from the combination of Synthorx and Sanofi. The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes. Synthorx has no commercial operations, and has made a negative contribution of € 106 million to Sanofi’s consolidated net income since the acquisition date. Acquisition-related costs were recognized in profit or loss mainly in the year ended December 31, 2019 within the line item Other operating expenses , and amounted to € 8 million . The cash outflow on this acquisition amounted to € 2,245 million , and was recorded in the line item Acquisitions of consolidated undertakings and investments accounted for using the equity method within the consolidated statement of cash flows . Transaction related to the equity-accounted investment in Regeneron From the beginning of April 2014, Sanofi accounted for its investment in Regeneron using the equity method. As from that date, in accordance with the Investor Agreement as amended in early 2014, Sanofi had the right to designate a member of the Regeneron Board of Directors. On May 29, 2020, Sanofi closed the transaction announced on May 25, 2020 involving the sale of its equity investment in Regeneron (with the exception of 400,000 shares), through (i) a registered public offering in the United States and internationally and (ii) a share repurchase by Regeneron. Sanofi sold 13 million shares of Regeneron common stock (of which 10.6 million were sold by Sanofi) through the public offering at a price of $515 per share, raising a total amount of $6,703 million; and Regeneron repurchased 9.8 million of its own shares of common stock directly from Sanofi for $5,000 million, at the offer price less a subscription discount ($509.85 per share). The total sale proceeds (before transaction-related costs) amounted to €10,575 million. At the same time, Sanofi as a result of this transaction lost the right to designate a member of the Regeneron Board of Directors under the amended Investor Agreement. Finally, as of May 29, 2020 Sanofi retained ownership of 400,000 Regeneron shares in order to continue to partially fund its commitments to invest in the development programs for cemiplimab (REGN2810) and dupilumab, in line with the 2018 Letter Agreement under which Sanofi is permitted to sell up to 1.4 million shares through the end of 2020. As of December 31, 2020, Sanofi had sold 779,320 Regeneron shares under that agreement. The number of Regeneron shares retained by Sanofi is 279,766 as of December 31, 2020 (see Note C.1.). Sanofi’s equity investment in Regeneron was accounted for by the equity method until May 29, 2020. As of that date, the carrying amount of the investment was €3,668 million; that amount was reversed out on closing of the transaction. Before tax effects, the gain on the divestment amounted to €7,382 million, including (i) a gain of €318 million arising on the currency translation reserve associated with Regeneron, which was taken to profit or loss in accordance with IAS 21; (ii) the deduction of transaction-related costs of €64 million; and (iii) a gain of €157 million on the remeasurement of the 400,000 retained shares at their quoted market price as of May 29, 2020 ($612.81). In accordance with IFRS 9 (Financial Instruments), the retained shares were classified in the “Equity instruments at fair value through other comprehensive income” category on the transaction date, at a value of €221 million (see Note D.7.). The tax charge arising on the transaction was €502 million. Given the material impact of this transaction, and to facilitate users’ understanding of the financial statements, the pre-tax gain on this transaction is presented as a separate line item in the consolidated income statement, Gain on Regeneron investment arising from the transaction of May 29, 2020 . The net cash inflow from the transaction was €10,370 million, which (for the reason cited above) is presented as a separate line item in the consolidated statement of cash flows, Net proceeds from sale of Regeneron shares on May 29, 2020. Sale of Seprafilm ® On November 27, 2019, Sanofi entered into a definitive agreement to sell Seprafilm ® to Baxter. The sale was completed on February 14, 2020. Sanofi recognized a pre-tax gain of €129 million. The impact of this sale, reflected in the line item Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax within the consolidated statement of cash flows, was a net cash inflow before tax of €311 million. D.2.1. Principal changes in the scope of consolidation in 2019 The impacts of the acquisitions carried out in 2019 are not material to the Sanofi consolidated financial statements, and Sanofi did not divest any material operations or companies during the year. Regeneron Pharmaceuticals, Inc. (Regeneron) Changes in the equity interest held by Sanofi in Regeneron during 2019 and 2018 are set forth below: (€ million) 2019 2018 Carrying amount (a) 3,342 3,055 Equity interest 21.2 % 21.7 % Acquisitions of shares — — Disposals of shares (b) 33 24 (a) See Note D.6. ® , Dupixent ® and REGN3500 (SAR440340) (see Note C.1.). As mentioned in Note D.1., following the sale of 22.8 million shares of Regeneron common stock on May 29, 2020, Sanofi ceased to exercise significant influence over Regeneron, as a result of which Sanofi's interest in Regeneron is no longer accounted for using the equity method (see Note D.6.). D.2.2. Principal changes in the scope of consolidation in 2018 Acquisition of Bioverativ Following a public tender offer, on March 8, 2018 Sanofi acquired the entire share capital of Bioverativ, a biotechnology company specializing in the development of treatments for hemophilia and other rare blood disorders, for a total consideration of $11.6 billion (€9.4 billion). The final purchase price allocation resulted in the recognition of goodwill amounting to €2,676 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 8,113 Inventories 145 Cash and cash equivalents 422 Other current and non-current assets and liabilities 16 True North Therapeutics contingent consideration liability (226) Net deferred tax position (1,792) Net assets of Bioverativ 6,678 Goodwill 2,676 Purchase price 9,354 The other intangible assets recognized mainly comprise the marketed hemophilia products Eloctate ® and Alprolix ® , and development projects relating to treatments for rare blood disorders. Goodwill represents (i) the pipeline of future products in early-stage research and development not identified individually at the acquisition date; (ii) the capacity to draw on a specialized structure to refresh the existing product portfolio; (iii) the competencies of Bioverativ staff; (iv) the benefits derived from the creation of new growth platforms; and (v) the expected future synergies and other benefits from the combination of Bioverativ and Sanofi. The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes . No material adjustment was required on completion of the final purchase price allocation. Acquisition of Ablynx On May 14, 2018, following a public tender offer, Sanofi acquired 95.60% of the share capital of Ablynx, a biopharmaceutical company specializing in the discovery and development of Nanobodies ® . On June 19, 2018, following the expiration of the squeeze-out procedure, Sanofi announced that it held the entire share capital of Ablynx, representing a total investment of €3,897 million. The final purchase price allocation resulted in the recognition of goodwill amounting to €1,360 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 2,409 Cash and cash equivalents 258 Other current and non-current assets and liabilities 131 Net deferred tax position (261) Net assets of Ablynx 2,537 Goodwill 1,360 Purchase price 3,897 The other intangible assets acquired mainly comprise rights to (i) Cablivi ® , a medicine for the treatment of adults who have experienced an episode of acquired thrombotic thrombocytopenic purpura (aTTP) and (ii) the exploitation of technology developed by Ablynx that uses camelid antibody fragments (Nanobodies ® ) to discover and identify multi-specific molecules targeting multiple diseases in various therapeutic fields. Goodwill represents the pipeline of future products in early-stage research and development not identified individually at the acquisition date, and the potential for those products to replace the existing product portfolio over the long term using resources and competencies specific to Ablynx, together with the expected future synergies and other benefits from the combination of Ablynx and Sanofi. The goodwill generated on this acquisition did not give rise to any deduction for income tax purposes . No material adjustments were required further to the final purchase price allocation. Divestment of the European Generics business On September 30, 2018, Sanofi finalized the divestment of its European Generics business. Sanofi recognized a gain of €510 million before taxes. An analysis of the assets and liabilities divested is set forth below: (€ million) September 30, 2018 Assets Property, plant and equipment 120 Goodwill 913 Other intangible assets 75 Other non-current assets 1 Deferred tax assets 83 Inventories 129 Accounts receivable 107 Other current assets 40 Cash and cash equivalents 122 Total assets of the divested European Generics business 1,590 Liabilities Non-current provisions and other non-current liabilities 27 Deferred tax liabilities 14 Accounts payable 91 Other current liabilities 216 Short-term debt and current portion of long-term debt 46 Total liabilities of the divested European Generics business 394 The cash inflow on this divestment amounted to €1,598 million, and was recorded in the line item Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax within the consolidated statement of cash flows.

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2020
Property, plant and equipment [abstract]
Property, plant and equipment	Property, plant and equipment D.3.1. Property, plant and equipment owned Property, plant and equipment owned by Sanofi (including property, plant and equipment acquired under finance leases for 2018, prior to the application of IFRS 16) is comprised of the following items: (€ million) Land Buildings Machinery Fixtures, Property, plant Total Gross value at January 1, 2018 318 6,768 10,145 2,450 2,297 21,978 Changes in scope of consolidation — 6 11 4 1 22 Acquisitions and other increases — 22 48 71 1,318 1,459 Disposals and other decreases (23) (227) (272) (127) (20) (669) Currency translation differences — 57 26 17 11 111 Transfers (a) (12) 257 510 164 (1,123) (204) Gross value at December 31, 2018 283 6,883 10,468 2,579 2,484 22,697 Acquisitions and other increases — 10 50 56 1,145 1,261 Disposals and other decreases (3) (42) (148) (114) (12) (319) Currency translation differences 6 80 64 17 33 200 Transfers (a) (31) 351 619 49 (1,259) (271) Gross value at December 31, 2019 255 7,282 11,053 2,587 2,391 23,568 Changes in scope of consolidation — 6 3 1 — 10 Acquisitions and other increases — 16 40 46 1,208 1,310 Disposals and other decreases (11) (173) (177) (123) (3) (487) Currency translation differences (13) (264) (276) (67) (91) (711) Transfers (a) 5 (39) 484 80 (1,051) (521) Gross value at December 31, 2020 236 6,828 11,127 2,524 2,454 23,169 Accumulated depreciation & impairment at January 1, 2018 (20) (3,612) (6,885) (1,804) (78) (12,399) Depreciation expense — (351) (595) (191) — (1,137) Impairment losses, net of reversals (8) (24) (40) (11) (12) (95) Disposals and other decreases 8 170 235 110 3 526 Currency translation differences — (29) (15) (14) — (58) Transfers (a) 1 50 70 (4) — 117 Accumulated depreciation & impairment at December 31, 2018 (19) (3,796) (7,230) (1,914) (87) (13,046) Depreciation expense — (357) (586) (194) — (1,137) Impairment losses, net of reversals (4) (33) (4) (2) (55) (98) Disposals and other decreases 2 54 140 106 11 313 Currency translation differences — (40) (40) (12) — (92) Transfers (a) 10 107 60 32 — 209 Accumulated depreciation & impairment at December 31, 2019 (11) (4,065) (7,660) (1,984) (131) (13,851) Depreciation expense — (356) (605) (182) — (1,143) Impairment losses, net of reversals — (24) (12) (7) — (43) Disposals and other decreases 1 168 166 117 8 460 Currency translation differences — 127 169 49 — 345 Transfers (a) — 252 150 26 — 428 Accumulated depreciation & impairment at December 31, 2020 (10) (3,898) (7,792) (1,981) (123) (13,804) Carrying amount at December 31, 2018 264 3,087 3,238 665 2,397 9,651 Carrying amount at December 31, 2019 244 3,217 3,393 603 2,260 9,717 Carrying amount at December 31, 2020 226 2,930 3,335 543 2,331 9,365 (a) This line mainly comprises property, plant and equipment in process brought into service during the period, but also includes the effect of the reclassification of assets to Assets held for sale or exchange , and for 2019 the reclassification of assets held under finance leases to Right-of-use assets on first-time application of IFRS 16. The table below sets forth acquisitions and capitalized interest by operating segment for the years ended December 31, 2020, 2019 and 2018: (€ million) 2020 2019 2018 Acquisitions 1,310 1,261 1,459 Pharmaceuticals 831 846 1,014 Industrial facilities 634 682 769 Research sites 152 87 14 Other 45 77 231 Vaccines 384 405 440 Consumer Healthcare 95 10 5 Capitalized interest 11 14 21 Off balance sheet commitments relating to property, plant and equipment as of December 31, 2020, 2019 and 2018 are set forth below: (€ million) 2020 2019 2018 Firm orders of property, plant and equipment 708 398 535 Property, plant and equipment pledged as security for liabilities — 107 123 Impairment tests of property, plant and equipment conducted using the method described in Note B.6. resulted in the recognition of the following net impairment losses in each of the last three financial periods: (€ million) 2020 2019 2018 Net impairment losses on property, plant and equipment 43 98 94 Due to the first-time application of IFRS 16 effective January 1, 2019, future minimum lease payments due under finance leases have since that date been recognized as part of the lease liability. Because Sanofi used the modified retrospective approach for transition, historical information has not been restated. However, as the prior standard (IAS 17) was applicable in preceding periods, finance lease assets and future minimum lease payments due under finance leases are shown in the tables below. The table below shows amounts for items of property, plant and equipment held under finance leases: (€ million) 2018 Buildings 73 Other property, plant and equipment 14 Total gross value 87 Accumulated depreciation and impairment (64) Carrying amount 23 Future minimum lease payments due under finance leases are shown in the table below: (€ million) 2018 Future minimum lease payments due under finance leases 25 of which interest 3 D.3.2. Property, plant and equipment leased - right-of-use assets On first-time application of IFRS 16 effective January 1, 2019, Sanofi used the modified retrospective approach for transition, and the historical information was not restated. Right-of-use assets relating to property, plant and equipment leased by Sanofi are analyzed in the table below: (€ million) Right-of-use assets Gross value at January 1, 2019 1,439 Acquisitions and other increases 157 Disposals and other decreases (31) Currency translation differences 18 Gross value at December 31, 2019 1,583 Changes in scope of consolidation 15 Acquisitions and other increases 340 Disposals and other decreases (121) Currency translation differences (85) Transfers (a) (21) Gross value at December 31, 2020 1,711 Accumulated depreciation & impairment at January 1, 2019 (8) Depreciation and amortization expense (b) (282) Disposals and other decreases 7 Accumulated depreciation & impairment at December 31, 2019 (283) Depreciation and amortization expense (b) (299) Disposals and other decreases 44 Currency translation differences 22 Transfers (a) 3 Accumulated depreciation & impairment at December 31, 2020 (513) Carrying amount at January 1, 2019 (c) 1,431 Carrying amount at December 31, 2019 1,300 Carrying amount at December 31, 2020 1,198 (a) This line also includes the effect of the reclassification of assets to Assets held for sale or exchange as of December 31, 2020. (b) Impairment losses against right of use assets amounted to €31 million as of December 31, 2020. and were immaterial as of December 31, 2019. (c) Sanofi elected the simplified retrospective method for first-time application of IFRS 16 (Leases), which involved recognizing a right-of-use asset equal to the lease liability, adjusted by the amount of any prepaid or accrued lease payments; impacts of the adoption of IFRS 16 on the balance sheet primarily included the recognition of right-of-use assets of €1,431 million, the recognition of current and non-current lease liabilities of €1,346 million, and an increase in provisions and other current and non-current liabilities of €73 million. Leased assets mainly comprise office and industrial premises (92%) and the vehicle fleet (8%) as of December 31, 2020. Annual lease costs on short term leases and low value asset leases amounted to €27 million in the year ended December 31, 2020, and to €50 million in the year ended December 31, 2019. Variable lease payments, sub-leasing activities, and sale-and-leaseback transactions were immaterial. Total cash outflows on leases (excluding annual lease costs on short term leases and low value asset leases) amounted to €269 million in the year ended December 31, 2020 and to €302 million in the year ended December 31, 2019. For information purposes, as the previous standard (IAS 17) was applicable in previous years, lease expense amounted to €345 million in 2018. A maturity analysis of the lease liability is disclosed in Note D.17.2. Commitments related to short-term leases and low value asset leases, including future payments for lease contracts committed but not yet commenced, are disclosed in Note D.21.

Goodwill and other intangible a

Goodwill and other intangible assets	12 Months Ended
	Dec. 31, 2020
Intangible Assets [Abstract]
Goodwill and other intangible assets	Goodwill and other intangible assets Movements in goodwill comprise: (€ million) Goodwill Balance at January 1, 2018 40,264 Acquisitions during the period 4,039 Other movements during the period (a) (1,006) Currency translation differences 938 Balance at December 31, 2018 44,235 Acquisitions during the period — Other movements during the period (a) (244) Currency translation differences 528 Balance at December 31, 2019 44,519 Acquisitions during the period 1,843 Other movements during the period (a) (75) Currency translation differences (1,923) Balance at December 31, 2020 44,364 (a) This line includes the amount of goodwill allocated to divested operations in accordance with paragraph 86 of IAS 36. In 2018, it mainly comprises the goodwill allocated to the European Generics business when it was divested (see Note D.2.2.). Acquisition of Principia (2020) The provisional purchase price allocation for Principia resulted in the recognition of intangible assets (other than goodwill) of €2,534 million as of the acquisition date (September 28, 2020), and of goodwill provisionally measured at €913 million as of the acquisition date (see Note D.1.). Acquisition of Synthorx (2020) The final purchase price allocation for Synthorx resulted in the recognition of intangible assets (other than goodwill) totaling €1,549 million as of the acquisition date (January 23, 2020), and of goodwill measured at €930 million as of the acquisition date (see Note D.1.). Acquisition of Bioverativ (2018) The final purchase price allocation for Bioverativ resulted in the recognition of intangible assets (other than goodwill) totaling €8,113 million at the acquisition date (March 8, 2018), and of goodwill measured at €2,676 million at the acquisition date (see Note D.2.2.). Acquisition of Ablynx (2018) The final purchase price allocation for Ablynx resulted in the recognition of intangible assets (other than goodwill) totaling €2,409 million at the acquisition date (May 14, 2018), and of goodwill measured at €1,360 million at the acquisition date (see Note D.2.2.). Movements in other intangible assets comprise: (€ million) Acquired R&D Products, Software Total other Gross value at January 1, 2018 3,679 53,638 1,368 58,685 Changes in scope of consolidation 3,632 6,889 2 10,523 Acquisitions and other increases 367 16 251 634 Disposals and other decreases (44) (920) (75) (1,039) Currency translation differences 218 1,757 10 1,985 Transfers (a) (430) 420 3 (7) Gross value at December 31, 2018 7,422 61,800 1,559 70,781 Acquisitions and other increases 272 19 184 475 Disposals and other decreases (236) (569) (50) (855) Currency translation differences 86 889 10 985 Transfers (a) (1,814) 1,814 (5) (5) Gross value at December 31, 2019 5,730 63,953 1,698 71,381 Changes in scope of consolidation 3,951 132 — 4,083 Acquisitions and other increases 654 58 137 849 Disposals and other decreases (44) (243) (46) (333) Currency translation differences (593) (2,926) (39) (3,558) Transfers (a) (98) 100 (2) — Gross value at December 31, 2020 9,600 61,074 1,748 72,422 Accumulated amortization & impairment at January 1, 2018 (2,204) (42,476) (925) (45,605) Amortization expense — (2,188) (115) (2,303) Impairment losses, net of reversals (b) (456) (264) (10) (730) Disposals and other decreases 36 840 68 944 Currency translation differences (54) (1,146) (6) (1,206) Transfers (a) — 6 2 8 Accumulated amortization & impairment at December 31, 2018 (2,678) (45,228) (986) (48,892) Amortization expense — (2,167) (134) (2,301) Impairment losses, net of reversals (b) (847) (2,757) (23) (3,627) Disposals and other decreases 158 488 51 697 Currency translation differences (31) (648) (8) (687) Transfers (a) 2 (2) 1 1 Accumulated amortization & impairment at December 31, 2019 (3,396) (50,314) (1,099) (54,809) Amortization expense — (1,707) (125) (1,832) Impairment losses, net of reversals (b) (328) (2) — (330) Disposals and other decreases 44 232 45 321 Currency translation differences 158 2,460 31 2,649 Transfers (a) 14 (14) — — Accumulated amortization & impairment at December 31, 2020 (3,508) (49,345) (1,148) (54,001) Carrying amount at December 31, 2018 4,744 16,572 573 21,889 Carrying amount at December 31, 2019 2,334 13,639 599 16,572 Carrying amount at December 31, 2020 6,092 11,729 600 18,421 (a) The “Transfers” line mainly relates to acquired R&D that came into commercial use during the period and is being amortized from the date of marketing approval. (b) See Note D.5. “Products, trademarks and other rights” mainly comprise: • "marketed products", with a carrying amount of €11.4 billion as of December 31, 2020 (versus €13.3 billion as of December 31, 2019 and €15.5 billion as of December 31, 2018) and a weighted average amortization period of approximately 10 years; and • "technological platforms", with a carrying amount of €0.2 billion as of December 31, 2020 (versus €0.2 billion as of December 31, 2019 and €0.2 billion as of December 31, 2018) and a weighted average amortization period of approximately 10 years. • "trademarks", with a carrying amount of €0.1 billion as of December 31, 2020 (versus €0.1 billion as of December 31, 2019 and €0.1 billion as of December 31, 2018) and a weighted average amortization period of approximately 12 years. The table below provides information about the principal "marketed products", which were recognized in connection with business combinations and represented 91% of the carrying amount of that item as of December 31, 2020: (€ million) Gross Accumulated Carrying amount at December 31, 2020 Amortization period (years) (a) Residual amortization period (years) (b) Carrying amount at December 31, 2019 Carrying amount at December 31, 2018 Genzyme 9,823 (8,338) 1,485 10 3 2,095 2,988 Boehringer Ingelheim 3,687 (1,198) 2,489 16 14 2,699 3,237 Aventis 32,474 (32,364) 110 9 7 219 409 Chattem 1,192 (590) 602 23 13 711 748 Protein Sciences 751 (197) 554 13 10 667 715 Ablynx 2,279 (418) 1,861 13 11 2,029 376 Bioverativ 6,516 (3,276) 3,240 13 11 3,788 6,385 Total: principal marketed products 56,722 (46,381) 10,341 12,208 14,858 (a) Weighted averages. The amortization periods for these products vary between 1 and 25 years. (b) Weighted averages. Acquisitions of other intangible assets (excluding software) during 2020 amounted to €692 million. During 2020, some of the acquired research and development came into commercial use, and started being amortized from the date of marketing approval; the main items involved were Sarclisa ® , indicated for the treatment of relapsed refractory multiple myeloma, and the meningococcal vaccine MenQuadfi ™ . During 2019, some of the acquired research and development came into commercial use, and started being amortized from the date of marketing approval; the item involved was the acquired thrombotic thrombocytopenic purpura (aTTP) treatment Cablivi ® . During 2018, some of the acquired research and development came into commercial use, and started being amortized from the date of marketing approval. The main item involved was the immuno-oncology product Libtayo ® (€348 million). Amortization of other intangible assets is recognized in the income statement within the line item Amortization of intangible assets , except for amortization of software and other rights of an industrial or operational nature which is recognized in the relevant classification of expense by function. An analysis of amortization of software is shown in the table below: (€ million) 2020 2019 2018 Cost of sales 19 11 21 Research and development expenses 2 3 4 Selling and general expenses 100 114 87 Other operating expenses 4 6 3 Total 125 134 115

Impairment of intangible assets

Impairment of intangible assets and property, plant and equipment	12 Months Ended
	Dec. 31, 2020
Impairment Of Assets [Abstract]
Impairment of intangible assets and property, plant and equipment	Impairment of intangible assets and property, plant and equipment Goodwill In accordance with IAS 36, goodwill is allocated to groups of cash generating units (CGUs) at a level corresponding to the Pharmaceuticals, Consumer Healthcare and Vaccines segments. When testing goodwill annually for impairment, the recoverable amount is determined for each segment on the basis of value in use, determined using discounted estimates of the future cash flows in accordance with the policies described in Note B.6.1. The allocation of goodwill as of December 31, 2020 is shown below: (€ million) Pharmaceuticals Consumer Healthcare Vaccines Total Goodwill 36,682 6,425 1,257 44,364 The value in use of each segment was determined by applying an after-tax discount rate to estimated future after-tax cash flows. A separate discount rate is used for each segment to reflect the specific economic conditions of that segment. The rates used for impairment testing in 2020 were 7.25% for the Pharmaceuticals segment, 7.00% for the Consumer Healthcare segment and 7.25% for the Vaccines segment; an identical value in use for Sanofi as a whole would be obtained by applying a uniform 7.2% rate to all three segments. The pre-tax discount rates applied to estimated pre-tax cash flows are calculated by iteration from the previously-determined value in use. Those pre-tax discount rates were 9.5% for the Pharmaceuticals segment, 8.9% for the Consumer Healthcare segment and 9.7% for the Vaccines segment, and equate to a uniform rate of 9.5% for Sanofi as a whole. The assumptions used in testing goodwill for impairment are reviewed annually. Apart from the discount rate, the principal assumptions used in 2020 were as follows: • The perpetual growth rates applied to future cash flows were zero for the Pharmaceuticals and Vaccines segments, and 1% for the Consumer Healthcare segment. • Sanofi also applies assumptions on the probability of success of current research and development projects, and more generally on its ability to renew the product portfolio in the longer term. Value in use (determined as described above) is compared with the carrying amount, and this comparison is then subjected to sensitivity analyses by reference to the principal parameters, including: • changes in the discount rate; • changes in the perpetual growth rate; and • fluctuations in operating margin. No impairment of goodwill would need to be recognized in the event of a reasonably possible change in the assumptions used in 2020. A value in use calculation for each of the segments would not result in an impairment loss using: • a discount rate up to 4.5 percentage points above the rates actually used; or • a perpetual growth rate up to 20.1 percentage points below the rates actually used; or • an operating margin up to 9.4 percentage points below the rates actually used. No impairment losses were recognized against goodwill in the years ended December 31, 2020, 2019 or 2018. Other intangible assets When there is evidence that an asset may have become impaired, the asset’s value in use is calculated by applying an after-tax discount rate to the estimated future after-tax cash flows from that asset. For the purposes of impairment testing, the tax cash flows relating to the asset are determined using a notional tax rate incorporating the notional tax benefit that would result from amortizing the asset if its value in use were regarded as its depreciable amount for tax purposes. Applying after-tax discount rates to after-tax cash flows gives the same values in use as would be obtained by applying pre-tax discount rates to pre-tax cash flows. The after-tax discount rates used in 2020 for impairment testing of other intangible assets in the Pharmaceuticals, Consumer Healthcare and Vaccines segments were obtained by adjusting Sanofi’s weighted average cost of capital to reflect specific country and business risks, giving after-tax discount rates in a range from 7.25% to 8.25%. In most instances, there are no market data that would enable fair value less costs to sell to be determined other than by means of developing a similar estimate based on future cash flows. Consequently, recoverable amount is in substance equal to value in use. The estimates used to determine value in use are sensitive to assumptions specific to the nature of the asset and to Sanofi's activities. Apart from the discount rate, the principal assumptions used in 2020 were as follows: • mid-term and long-term sales forecasts; • perpetual growth or attrition rates, when applicable; and • probability of success of current research and development projects. The assumptions used in testing intangible assets for impairment are reviewed at least annually. In 2020, 2019 and 2018, impairment testing of other intangible assets (excluding software) resulted in the recognition of net impairment losses as shown below: (€ million) 2020 2019 2018 Impairment of other intangible assets (excluding software) 330 3,604 720 Marketed products 2 2,757 264 Pharmaceuticals (a) 2 2,405 258 Vaccines — — 6 CHC (b) — 352 — Research and development projects (c) 328 847 454 Other (d) — — 2 (a) Impairment tests conducted on other intangible assets as of December 31, 2019 led to (i) the recognition of an impairment loss of €2,236 million on the product Eloctate ® (as part of the broader Eloctate ® franchise) and (ii) an impairment loss of €163 million on the marketed product Lemtrada ® , compared with €183 million as of December 31, 2018. (b) Impairment tests conducted on other intangible assets as of December 31, 2019 led to the recognition of an impairment loss of €352 million on assets related to Zantac ® . (c) For 2020, this line mainly comprises impairment losses taken against R&D programs within the Specialty Care GBU, and the discontinuation of certain R&D programs and collaboration agreements in Diabetes. For 2019, it relates mainly to (i) the allocation of the impairment loss recognized for the Eloctate ® franchise to the BIVV001 project (see (a) above), and (ii) the termination of the development program for sotagliflozin (€275 million). For 2018, this line relates mainly to intangible assets of Ablynx and to other R&D intellectual property assets, including the MyoKardia and efpeglenatide programs in Diabetes. (d) Not included within the line item Impairment of intangible assets in the consolidated income statements (see Note B.4.). Property, plant and equipment Impairment losses taken against property, plant and equipment are disclosed in Note D.3.

Investments accounted for using

Investments accounted for using the equity method	12 Months Ended
	Dec. 31, 2020
Interests In Other Entities [Abstract]
Investments accounted for using the equity method	Investments accounted for using the equity method Investments accounted for using the equity method comprise associates and joint ventures (see Note B.1.), and are set forth below. (€ million) % interest 2020 2019 2018 Regeneron Pharmaceuticals, Inc. (a) — — 3,342 3,055 Onduo LLC (b) 19.9 — — 108 Infraserv GmbH & Co. Höchst KG (c) 31.2 72 70 73 Entities and companies managed by Bristol-Myers Squibb (d) 100.0 — 37 40 Other investments — 129 142 126 Total 201 3,591 3,402 (a) Following the transaction of May 29, 2020 as described in Note D.1. above, which resulted in the divestment of 22.8 million Regeneron shares, Sanofi no longer exercises significant influence over Regeneron. As of that date, Sanofi retained 0.4 million Regeneron shares, classified in the “Equity instruments at fair value through other comprehensive income” category (see Note D.7.1.). As of December 31, 2020, Sanofi held 279,766 Regeneron shares. (b) As a result of the restructuring of Onduo LLC, finalized November 11, 2019, Sanofi lost significant influence over that entity on that date; this did not have a material impact on profit or loss in the year ended December 31, 2019. As of that date, Sanofi held a 19.9% equity interest in Onduo. As of December 31, 2020, Sanofi still held a 19.9% equity interest in Onduo. (c) Joint venture. (d) On February 28, 2020, Sanofi acquired from Bristol-Myers Squibb the remaining 50.1% equity interest not yet held by Sanofi in the three partnerships that organize the commercialization of Plavix ® in the United States and Puerto Rico, for a total consideration of $12 million. The acquisition was accounted for in accordance with IFRS 3 (Business Combinations). The table below shows Sanofi’s overall share of (i) profit or loss and (ii) other comprehensive income from investments accounted for using the equity method, showing the split between associates and joint ventures in accordance with IFRS 12 (the amounts for each individual associate or joint venture are not material): 2020 2019 2018 (€ million) Joint ventures Associates Joint ventures Associates Joint ventures Associates Share of profit/(loss) from investments accounted for using the equity method 4 355 (a) 15 240 17 482 Share of other comprehensive income from investments accounted for using the equity method 8 (311) (7) 90 (7) 105 Total 12 44 8 330 10 587 (a) Includes €343 million for Sanofi's share of the net income of Regeneron up to and including May 29, 2020 (see Note D.1.) The financial statements include arm’s length commercial transactions between Sanofi and some equity-accounted investments that are classified as related parties. The principal transactions and balances with related parties are summarized below: (€ million) 2020 2019 2018 Sales 75 24 35 Royalties and other income (a) 97 270 116 Accounts receivable and other receivables 50 151 89 Purchases and other expenses (including research expenses) (a) 747 1,334 1,143 Accounts payable and other payables 15 342 544 (a) For 2020, these amounts include transactions between Sanofi and Regeneron for the period from January 1 through May 29, 2020. The table above does not include the repurchase by Regeneron of its own shares from Sanofi (see Note D.1.). There were no funding commitments to associates and joint ventures as of December 31, 2020, compared with €67 million as of December 31, 2019. For off balance sheet commitments of an operational nature involving joint ventures, see Note D.21.1. Regeneron As mentioned in Note D.1., as a result of the sale of 22.8 million shares of Regeneron common stock on May 29, 2020, Sanofi ceased to exercise significant influence over Regeneron, and this investment is no longer accounted for using the equity method. Key items from the 2018 and 2019 consolidated financial statements of Regeneron, after adjustments to comply with IFRS (including those required to align on elective accounting treatments adopted by Sanofi) but before fair value remeasurements, are set forth below: (€ million) 2019 2018 Net sales and other revenues 7,023 5,680 Net income 1,882 2,476 Other comprehensive income for the period, net of taxes 113 (33) Comprehensive income 1,995 2,443 (€ million) December 31, 2019 December 31, 2018 Current assets 6,858 5,621 Non-current assets 6,627 4,731 Total assets 13,485 10,352 Current liabilities 1,870 1,258 Non-current liabilities 925 772 Total liabilities 2,795 2,030 Consolidated shareholders’ equity of Regeneron 10,690 8,322 The table below shows a reconciliation to the carrying amount of the investment: (€ million) December 31, 2019 December 31, 2018 % interest 21 % 22 % Share of equity attributable to Sanofi 2,263 1,806 Goodwill 839 858 Fair value remeasurements of assets and liabilities at the acquisition date 811 873 Other items (a) (571) (482) Carrying amount of the investment in Regeneron 3,342 3,055 (a) Mainly comprises the difference arising from Sanofi’s share of the accumulated profits and losses and other changes in the net assets of Regeneron for the periods prior to first-time application of the equity method, and thereafter (i) Sanofi’s share of the stock option expense recognized against equity in the books of Regeneron, and of the deferred taxes recognized against equity in respect of that expense in accordance with IAS 12 paragraph 68.C. and (ii) the effects of the elimination of internal profits between Sanofi and Regeneron. The market value of Sanofi’s investment in Regeneron as of December 31, 2019 and 2018, based on the quoted stock market price per share in US dollars, is shown below: 2019 2018 Quoted stock market price per share ($) 375.48 373.50 Market value of investment in Regeneron ($ million) 8,767 8,835 Market value of investment in Regeneron (€ million) 7,820 7,702

Other non-current assets

Other non-current assets	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Other non-current assets	Other non-current assets Other non-current assets comprise: (€ million) 2020 2019 2018 Equity instruments at fair value through other comprehensive income (D.7.1.) 588 380 1,037 Debt instruments at fair value through other comprehensive income (D.7.2.) 426 403 359 Other financial assets at fair value through profit or loss (D.7.3.) 890 892 733 Pre-funded pension obligations (Note D.19.1.) 177 155 77 Long-term prepaid expenses 92 115 126 Long-term loans and advances and other non-current receivables 537 521 464 Derivative financial instruments (Note D.20.) 24 37 19 Total 2,734 2,503 2,815 D.7.1. Equity instruments at fair value through other comprehensive income Quoted equity investments The main changes in the quoted equity investments included in the “Equity instruments at fair value through other comprehensive income” category during the year ended December 31, 2020 are described below: • As mentioned in Note D.1., following the sale of 22.8 million shares of Regeneron common stock on May 29, 2020, Sanofi ceased to exercise significant influence over Regeneron, and this investment is no longer accounted for using the equity method (see Note D.6.). In accordance with IFRS 9 (Financial Instruments), the 400,000 shares retained by Sanofi were classified in the "Equity instruments at fair value through other comprehensive income" category as of May 29, 2020, at a carrying amount of €221 million. As of December 31, 2020, Sanofi held 279,766 Regeneron shares with a carrying amount of €111 million. • An equity injection was made into Translate Bio under the terms of the collaboration and license agreement announced on June 23, 2020, with a carrying amount of €74 million as of December 31, 2020 and representing an equity interest of approximately 8% of Translate Bio as of that date. • Sanofi owns equity interests in quoted biotechnology companies. Movements in the quoted market prices of the shares held in those companies generated a net gain of €357 million, recognized in "Equity instruments at fair value through other comprehensive income" . The main changes in the quoted equity investments included in the “Equity instruments at fair value through other comprehensive income” category during the year ended December 31, 2019 are described below: • On May 2, 2019, further to the announcement on April 8, 2019 of amendments to the terms of the agreement governing Sanofi’s equity interest in Alnylam, Sanofi divested its entire holding of 10.6 million Alnylam shares, representing approximately 10% of Alnylam's equity capital. Proceeds from the divestment amounted to €706 million, net of taxes. The loss on the divestment was recognized in full in Other comprehensive income . This equity interest had a carrying amount of €671 million as of December 31, 2018. • The entire equity interest held by Sanofi in MyoKardia, Inc. was divested during the first half of 2019. Proceeds from the divestment amounted to €118 million, net of taxes. The gain arising on the divestment was recognized in full in Other comprehensive income . This equity interest had a carrying amount of €178 million as of December 31, 2018. • Following the restructuring of Onduo LLC, finalized November 11, 2019, Sanofi received from Onduo a dividend in the form of DexCom shares valued at $122 million. As of December 31, 2020, those shares had a carrying amount of €90 million, versus €104 million as of December 31, 2019. A 10% decline in stock prices of the quoted equity investments included within “Equity instruments at fair value through other comprehensive income” would have had a negative pre-tax impact of €44 million on Other comprehensive income as of December 31, 2020. Unquoted equity investments The line item “Equity instruments at fair value through other comprehensive income” also includes equity investments not quoted in an active market. The carrying amount of those investments was €149 million as of December 31, 2020 and €266 million as of December 31, 2019. D.7.2. Debt instruments at fair value through other comprehensive income The “Debt instruments at fair value through other comprehensive income” category includes quoted euro-denominated senior bonds amounting to €426 million as of December 31, 2020, including €172 million of securities obtained in exchange for financial assets held to meet obligations to employees under post-employment benefit plans. Sanofi held €403 million of quoted senior bonds as of December 31, 2019 and €359 million as of December 31, 2018. As regards debt instruments held to meet obligations to employees under post-employment benefit plans, a reduction of 10 basis points in market interest rates as of December 31, 2020 would have had a pre-tax impact of €3 million on Other comprehensive income . As regards other quoted debt instruments, a reduction of 10 basis points in market interest rates as of December 31, 2020 would have had a pre-tax impact of €1 million on Other comprehensive income . Other comprehensive income recognized in respect of “Equity instruments at fair value through other comprehensive income” and “Debt instruments at fair value through other comprehensive income” represented unrealized after-tax gains of €200 million as of December 31, 2020, versus unrealized after-tax losses of €80 million as of December 31, 2019 and € 148 million as of December 31, 2018. An analysis of the change in gains and losses recognized in Other comprehensive income , and of items reclassified to profit or loss, is presented in Note D.15.7. D.7.3. Other financial assets at fair value through profit or loss The “Other financial assets at fair value through profit or loss” category includes: • Contingent consideration receivable by Sanofi following the dissolution of the Sanofi Pasteur MSD (SPMSD) joint venture, based on a percentage of MSD’s future sales during the 2017-2024 period of specified products previously distributed by SPMSD (see Notes B.1. and D.12.). The fair value of the MSD contingent consideration was determined by applying the royalty percentage stipulated in the contract to discounted sales projections. A reduction of one percentage point in the discount rate would increase the fair value of the MSD contingent consideration by approximately 2%. Changes in the fair value of this contingent consideration are recognized in the income statement within the line item Fair value remeasurement of contingent consideration (see Note B.18.). As of December 31, 2020, the contingent consideration asset amounted to €483 million (including a non-current portion of €374 million), versus €492 million (non-current portion: €398 million) as of December 31, 2019 and €373 million as of December 31, 2018. • A portfolio of financial investments (amounting to €453 million as of December 31, 2020) held to fund a deferred compensation plan provided to certain employees (versus €442 million as of December 31, 2019 and €363 million as of December 31, 2018). • Unlisted securities not meeting the definition of equity instruments totaling €63 million as of December 31, 2020 (versus €52 million as of December 31, 2019 and €61 million as of December 31, 2018).

Assets held for sale or exchang

Assets held for sale or exchange and liabilities related to assets held for sale or exchange	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Assets held for sale or exchange and liabilities related to assets held for sale or exchange	Assets held for sale or exchange and liabilities related to assets held for sale or exchange Assets held for sale or exchange, and liabilities related to assets held for sale or exchange, comprise: (€ million) December 31, 2020 December 31, 2019 December 31, 2018 Assets held for sale or exchange 83 325 68 Liabilities related to assets held for sale or exchange 32 6 — As of December 31, 2020, assets held for sale mainly related to the planned divestment of an industrial facility in North America. As of December 31, 2019, assets held for sale mainly comprised assets associated with the sale of Seprafilm ® , which was completed in the first half of 2020.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Inventories	Inventories Inventories comprise the following: 2020 2019 2018 (€ million) Gross Allowances Carrying Gross Allowances Carrying Gross Allowances Carrying Raw materials 1,051 (76) 975 1,163 (76) 1,087 1,099 (83) 1,016 Work in process 5,398 (542) 4,856 5,104 (582) 4,522 4,637 (549) 4,088 Finished goods 2,739 (218) 2,521 2,629 (244) 2,385 2,533 (160) 2,373 Total 9,188 (836) 8,352 8,896 (902) 7,994 8,269 (792) 7,477 Allowances include write-downs of products on hand pending marketing approval. Inventories pledged as security for liabilities amounted to €17 million as of December 31, 2020 (versus €15 million as of December 31, 2019 and €18 million as of December 31, 2018).

Accounts receivable

Accounts receivable	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Accounts receivable	Accounts receivable Accounts receivable break down as follows: (€ million) December 31, 2020 December 31, 2019 December 31, 2018 Gross value 7,633 8,090 7,430 Allowances (142) (153) (170) Carrying amount 7,491 7,937 7,260 The impact of allowances against accounts receivable in 2020 was a net expense of €30 million (versus a net gain of €5 million in 2019 and a net expense of €15 million in 2018). The gross value of overdue receivables was €549 million as of December 31, 2020, compared with €642 million as of December 31, 2019 and €547 million as of December 31, 2018. Overdue accounts Overdue by Overdue by Overdue by Overdue by Overdue by (€ million) gross value <1 month 1 to 3 months 3 to 6 months 6 to 12 months > 12 months December 31, 2020 549 271 97 52 34 95 December 31, 2019 642 269 171 61 36 105 December 31, 2018 547 257 172 36 21 61 Amounts overdue by more than one month relate mainly to public-sector customers. Some Sanofi subsidiaries have assigned receivables to factoring companies or banks without recourse. The amount of receivables derecognized was €18 million as of December 31, 2020 (€214 million as of December 31, 2019 and €385 million as of December 31, 2018). The €18 million derecognized in 2020 related to Europe. The residual guarantees relating to such transfers were immaterial as of December 31, 2020.

Other current assets

Other current assets	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Other current assets	Other current assets An analysis of Other current assets is set forth below: (€ million) 2020 2019 2018 Tax receivables, other than corporate income taxes 687 603 564 Other receivables 567 735 627 Prepaid expenses 525 493 469 Interest rate derivatives measured at fair value (see Note D.20.) — 4 30 Currency derivatives measured at fair value (see Note D.20.) 58 184 134 Other current financial assets (a) 900 426 199 Total 2,737 2,445 2,023

Financial assets and liabilitie

Financial assets and liabilities measured at fair value	12 Months Ended
	Dec. 31, 2020
Fair Value Measurement [Abstract]
Financial assets and liabilities measured at fair value	Financial assets and liabilities measured at fair value Under IFRS 7 (Financial Instruments: Disclosures), fair value measurements must be classified using a fair value hierarchy with the following levels: • level 1: quoted prices in active markets for identical assets or liabilities (without modification or repackaging); • level 2: quoted prices in active markets for similar assets and liabilities, or valuation techniques in which all important inputs are derived from observable market data; • level 3: valuation techniques in which not all important inputs are derived from observable market data. The valuation techniques used are described in Note B.8.5. The table below shows the balance sheet amounts of assets and liabilities measured at fair value. 2020 2019 2018 Level in the fair value hierarchy Level in the fair value Level in the fair value (€ million) Note Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Financial assets measured at fair value Quoted equity investments D.7.1. 439 — — 114 — — 859 — — Unquoted equity investments D.7.1. — — 149 — — 290 — — 197 Quoted debt securities D.7.2. 426 — — 403 — — 359 — — Unquoted debt securities not meeting the definition of equity instruments D.7.3. — — 63 — — 52 — — 61 Contingent consideration relating to divestments D.7.3. — — 483 — — 492 — — 373 Financial assets held to meet obligations under deferred compensation plans D.7.3. and D.11. 454 — — 442 — — 364 — — Non-current derivatives D.7. — 24 — — 37 — — 19 — Current derivatives D.11. — 58 — — 188 — — 164 — Mutual fund investments D.13. 8,703 — — 5,304 — — 3,189 — — Total financial assets measured at fair value 10,022 82 695 6,263 225 834 4,771 183 631 Financial liabilities measured at fair value CVRs issued in connection with the acquisition of Genzyme D.18. — — — — — — 99 — — Bayer contingent purchase consideration arising from the acquisition of Genzyme D.18. — — 104 — — 156 — — 472 MSD contingent consideration (European vaccines business) D.18. — — 312 — — 385 — — 410 Other contingent consideration arising from business combinations D.18. — — 189 — — 259 — — 301 Liabilities related to non-controlling interests D.18. — — — — — — — — 22 Non-current derivatives D.19. — 92 — — 10 — — 7 — Current derivatives D.19.5 — 205 — — 89 — — 90 — Total financial liabilities measured at fair value — 297 605 — 99 800 99 97 1,205 No transfers between the different levels of the fair value hierarchy occurred during 2020. In connection with the dissolution of the Sanofi Pasteur MSD (SPMSD) joint venture, finalized on December 31, 2016, Sanofi recognized contingent consideration receivable as a financial asset at fair value through profit or loss (see Note D.7.3.), and contingent consideration payable in Liabilities related to business combinations and to non-controlling interests (see Note D.18.). As of December 31, 2020: • the financial asset relating to contingent consideration receivable by Sanofi based on a percentage of MSD’s future sales during the 2017-2024 period of specified products previously distributed by SPMSD amounted to €483 million; and • the financial liability relating to contingent consideration payable to MSD based on a percentage of future sales made by Sanofi Pasteur during the 2017-2024 period of specified products previously distributed by SPMSD amounted to €312 million.

Cash and cash equivalents

Cash and cash equivalents	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Cash and cash equivalents	Cash and cash equivalents (€ million) 2020 2019 2018 Cash 1,144 701 661 Cash equivalents (a) 12,771 8,726 6,264 Cash and cash equivalents 13,915 9,427 6,925 (a) As of December 31, 2020, cash equivalents mainly comprised the following: (i) €8,703 million invested in euro and US dollar denominated money-market mutual funds (December 31, 2019: €5,304 million; December 31, 2018: €3,189 million); (ii) €3,259 million of term deposits (December 31, 2019: €2,211 million; December 31, 2018: €2,014 million) and (iii) €74 million in commercial paper (December 31, 2019: €446 million; December 31, 2018: €357 million). Cash equivalents also include €425 million held by captive insurance and reinsurance companies in accordance with insurance regulations (December 31, 2019: €456 million; December 31, 2018: €505 million).

Net deferred tax position

Net deferred tax position	12 Months Ended
	Dec. 31, 2020
Income Taxes [Abstract]
Net deferred tax position	Net deferred tax position An analysis of the net deferred tax position is set forth below: (€ million) 2020 2019 2018 Deferred taxes on: Consolidation adjustments (intragroup margin in inventory) 1,142 1,270 1,195 Provision for pensions and other employee benefits 1,213 1,327 1,166 Remeasurement of other acquired intangible assets (3,083) (a) (2,656) (3,740) Recognition of acquired property, plant and equipment at fair value (27) (33) (31) Equity interests in subsidiaries and investments in other entities (b) (522) (421) (437) Tax losses available for carry-forward 1,327 1,323 1,341 Stock options and other share-based payments 88 142 110 Accrued expenses and provisions deductible at the time of payment (c) 1,399 1,405 1,394 Other (d) 905 783 201 Net deferred tax asset/(liability) 2,442 3,140 1,199 (a) As of December 31, 2020, includes remeasurements of the acquired intangible assets of Bioverativ ( €1,021 million), Principia (€547 million), Genzyme (€367 million) and Synthorx (€315 million). (b) In some countries, Sanofi is liable for withholding taxes and other tax charges when dividends are distributed. Consequently, Sanofi recognizes a deferred tax liability on the reserves of French and foreign subsidiaries (approximately €47.8 billion) which it regards as likely to be distributed in the foreseeable future. In determining the amount of the deferred tax liability as of December 31, 2020, Sanofi took into account changes in the ownership structure of certain subsidiaries, and the effects of changes in the taxation of dividends in France following the ruling of the Court of Justice of the European Union in the Steria case and the resulting amendments to the 2015 Finance Act. (c) Includes deferred tax assets related to restructuring provisions, amounting to €307 million as of December 31, 2020, €259 million as of December 31, 2019, and €218 million as of December 31, 2018. (d) The 2019 movement in the "Other" line mainly comprises the recognition of a deferred tax asset on an internal transfer of intangible assets. The reserves of Sanofi subsidiaries that would be taxable if distributed but for which no distribution is planned, and for which no deferred tax liability has therefore been recognized, totaled €11.5 billion as of December 31, 2020, compared with €10.9 billion as of December 31, 2019 and €10.2 billion as of December 31, 2018. Most of Sanofi’s tax loss carry-forwards are available indefinitely. For a description of policies on the recognition of deferred tax assets, refer to Note B.22. For each tax consolidation, the recognition of deferred tax assets is determined on the basis of profit forecasts that are consistent with Sanofi’s medium-term strategic plan, and taking into consideration the tax consequences of the strategic opportunities available to Sanofi within the period of availability of tax loss carry-forwards and the specific circumstances of each tax consolidation. Deferred tax assets relating to tax loss carry-forwards as of December 31, 2020 amounted to €1,658 million, of which €331 million were not recognized. This compares with €1,640 million as of December 31, 2019 (of which €317 million were not recognized) and €1,651 million as of December 31, 2018 (of which €310 million were not recognized). The table below shows when tax losses available for carry-forward are due to expire: (€ million) Tax losses available for carry-forward (a) 2021 53 2022 37 2023 36 2024 10 2025 38 2026 and later 6,341 Total as of December 31, 2020 6,515 Total as of December 31, 2019 6,401 Total as of December 31, 2018 6,100 (a) Excluding tax loss carry-forwards on asset disposals. Such carry-forwards amounted to €6 million as of December 31, 2020, and €1 million as of December 31, 2019 and December 31, 2018. Use of tax loss carry-forwards is limited to the entity in which they arose. In jurisdictions where tax consolidations are in place, tax losses can be netted against taxable income generated by entities in the same tax consolidation. Deferred tax assets not recognized because their future recovery was not regarded as probable given the expected results of the entities in question amounted to €346 million in 2020, €340 million in 2019 and €298 million in 2018.

Consolidated shareholders_ equi

Consolidated shareholders’ equity	12 Months Ended
	Dec. 31, 2020
Share Capital, Reserves And Other Equity Interest [Abstract]
Consolidated shareholders' equity	Consolidated shareholders’ equity D.15.1. Share capital As of December 31, 2020, the share capital was €2,517,943,476, consisting of 1,258,971,738 shares with a par value of €2. Treasury shares held by Sanofi are as follows: Number of shares (million) % of share capital for the period December 31, 2020 8.28 0.658 % December 31, 2019 0.02 0.002 % December 31, 2018 1.94 0.156 % January 1, 2018 0.17 0.014 % Treasury shares are deducted from shareholders’ equity. Gains and losses on disposals of treasury shares are recorded directly in equity and are not recognized in net income for the period. Movements in the share capital of the Sanofi parent company over the last three years are set forth below: Date Transaction Number of shares December 31, 2017 1,254,019,904 During 2018 Capital increase by exercise of stock subscription options (a) 1,168,808 During 2018 Capital increase by issuance of restricted shares (b) 2,152,183 Board meeting of April 26, 2018 Reduction in share capital by cancellation of treasury shares (7,239,803) Board meeting of July 27, 2018 Capital increase reserved for employees 2,401,184 Board meeting of December 18, 2018 Reduction in share capital by cancellation of treasury shares (5,106,804) December 31, 2018 1,247,395,472 During 2019 Capital increase by exercise of stock subscription options (a) 2,745,853 During 2019 Capital increase by issuance of restricted shares (b) 3,704,786 December 31, 2019 1,253,846,111 During 2020 Capital increase by exercise of stock subscription options (a) 868,655 During 2020 Capital increase by issuance of restricted shares (b) 1,666,256 Board meeting of July 28, 2020 Capital increase reserved for employees 2,590,716 December 31, 2020 1,258,971,738 (a) Shares issued on exercise of Sanofi stock subscription options. (b) Shares vesting under restricted share plans and issued in the period. For the disclosures about the management of capital required under IFRS 7, refer to Note B.27. D.15.2. Restricted share plans Restricted share plans are accounted for in accordance with the policies described in Note B.24.3. The principal characteristics of those plans are as follows: 2020 2019 2018 Type of plan Performance Performance Performance Performance Performance Date of Board meeting approving the plan April 28, 2020 October 28, 2020 April 30, 2019 July 30, 2018 May 2, 2018 Service period 3 years 3 years 3 years 3 years 3 years Total number of shares awarded in 2018 and 2019 3,797,582 141,669 4,390,216 Fair value per share awarded (€) (a) 67.90 64.35 56.59 Total number of shares awarded in 2020 3,340,501 73,027 Of which with no market condition 2,536,893 — Fair value per share awarded (€) (a) 82.36 — Of which with market condition 803,608 73,027 Fair value per share awarded (€) (b) 76.11 63.18 Fair value of plan at the date of grant (€ million) 270 5 258 9 248 (a) Market price of Sanofi shares at the date of grant, adjusted for dividends expected during the vesting period. (b) Weighting between (i) fair value determined using the Monte Carlo model and (ii) market price of Sanofi shares at the date of grant, adjusted for dividends expected during the vesting period. The total expense recognized for all restricted share plans, and the number of restricted shares not yet fully vested, are shown in the table below: 2020 2019 2018 Total expense for restricted share plans (€ million) 222 247 248 Number of shares not yet fully vested 10,546,612 10,908,503 13,576,464 Under 2020 plans 3,284,558 — — Under 2019 plans 3,375,717 3,662,806 — Under 2018 plans 3,886,337 4,117,795 4,406,593 Under 2017 plans — 3,127,902 3,314,391 Under 2016 plans — — 3,690,226 Under 2015 plans — — 2,165,254 D.15.3. Capital increases The characteristics of the employee share ownership plans awarded in the form of a capital increase reserved for employees in 2020 and 2018 are summarized in the table below; there were no capital increases reserved for employees in 2019. 2020 2018 Date of Board meeting approving the plan February 5, 2020 March 6, 2018 Subscription price (€) (a) 70.67 52.66 Subscription period June 8-26, 2020 June 11-29, 2018 Number of shares subscribed 2,467,101 2,298,783 Number of shares issued immediately as employer’s contribution 123,615 102,401 (a) Subscription price representing 80% of the average of the opening quoted market prices of Sanofi shares during the 20 trading days preceding June 2, 2020 and June 9, 2018, respectively. The table below sets forth the expense recognized for each plan: (€ million) 2020 2018 Expense recognized 52 32 of which employer’s contribution 11 7 D.15.4. Repurchase of Sanofi shares The Annual General Meetings of Sanofi shareholders held on April 28 2020, April 30, 2019, May 2, 2018 and May 10, 2017 each authorized a share repurchase program for a period of 18 months. The following repurchases have been made under those programs: (in number of shares and € million) Year of authorization 2020 2019 2018 Number of shares Value Number of shares Value Number of shares Value 2020 program 5,685,426 461 — — — — 2019 program 3,982,939 361 — — — — 2018 program — — 147,793 12 6,884,792 501 2017 program — — — — 8,489,873 602 D.15.5. Reductions in share capital Reductions in share capital for the accounting periods presented are described in the table included at Note D.15.1. above. Those reductions have no impact on shareholders’ equity. D.15.6. Currency translation differences Currency translation differences comprise the following: (€ million) 2020 2019 2018 Attributable to equity holders of Sanofi (3,386) 632 (167) Attributable to non-controlling interests (55) (36) (36) Total (3,441) 596 (203) The balance as of December 31, 2020 includes an after-tax amount of €(136) million relating to hedges of net investments in foreign operations (refer to Note B.8.3. for a description of the relevant accounting policy), versus €(260) million as of December 31, 2019 and €(145) million as of December 31, 2018. The movement in Currency translation differences is mainly attributable to the US dollar. D.15.7. Other comprehensive income Movements within other comprehensive income are shown below: (€ million) 2020 2019 2018 Actuarial gains/(losses): • Actuarial gains/(losses) excluding investments accounted for using the equity method (see Note D.19.1.) (267) (377) 201 • Actuarial gains/(losses) of investments accounted for using the equity method, net of taxes (1) (5) — • Tax effects 45 161 (69) Equity instruments included in financial assets and financial liabilities: • Change in fair value (excluding investments accounted for using the equity method) 358 30 (529) • Change in fair value (investments accounted for using the equity method, net of taxes) (14) 80 (8) • Equity risk hedging instruments designated as fair value hedges (24) (4) — • Tax effects (85) (48) 100 Items not subsequently reclassifiable to profit or loss 12 (163) (305) Debt instruments included in financial assets: • Change in fair value (excluding investments accounted for using the equity method) (a) 15 28 (4) • Change in fair value (investments accounted for using the equity method, net of taxes) — — — • Tax effects (3) (5) — Cash flow hedges: • Change in fair value (excluding investments accounted for using the equity method) (b) 4 (13) 3 • Change in fair value (investments accounted for using the equity method, net of taxes) — — — ▪ Tax effects (2) 4 (1) Change in currency translation differences: • Currency translation differences on foreign subsidiaries (excluding investments accounted for using the equity method) (b) (3,872) 850 1,273 • Currency translation differences (investments accounted for using the equity method) (b) 32 64 106 • Currency translation differences related to the investment in Regeneron and reclassified to profit or loss (c) (318) — — • Hedges of net investments in foreign operations (b) 180 (163) (185) • Tax effects (c) (58) 48 72 Items subsequently reclassifiable to profit or loss (4,022) 813 1,264 (a) Amounts reclassified to profit or loss: €5 million in 2020, and immaterial in 2019 and 2018. (b) Amounts reclassified to profit or loss: €1 million in 2020, €27 million in 2019 and €(7) million in 2018. (c) Relates to the translation reserve arising on the investment in Regeneron, which was reclassified to profit or loss in accordance with IAS 21 (The Effects of Changes in Foreign Exchange Rates), of which €2 million (net of tax) related to hedges of net investments in foreign operations. D.15.8. Stock options Stock option plans awarded and measurement of stock option plans No stock options were awarded during 2020. Stock options granted by the Board of Directors in 2019 and 2018 are summarized below, with the assumptions used to determine their fair value: 2019 2018 Date of Board meeting approving the plan April 30, 2019 May 2, 2018 Total number of options granted 220,000 220,000 Exercise price (€) 76.71 65.84 Vesting period 4 years 4 years Plan expiry date April 30, 2029 May 2, 2028 Fair value of the plan (€ million) 2 1 Fair value per option granted (€) 7.80 6.32 Assumptions used to determine fair value Dividend yield 4.31 % 4.87 % Volatility of Sanofi shares, computed on a historical basis 22.48 % 23.10 % Risk-free interest rate 0.15 % 0.36 % Plan maturity 8 years 7 years The expense recognized through equity for stock option plans is immaterial. Stock subscription option plans Details of the terms of exercise of stock subscription options granted under the various plans are presented below in Sanofi share equivalents. These plans were awarded to certain corporate officers and employees of Sanofi companies. The table shows all Sanofi stock subscription option plans still outstanding or under which options were exercised in the year ended December 31, 2020: Source Date of grant Number of Start date of Expiry date Exercise Number of options outstanding as of 12/31/2020 Sanofi-aventis 03/01/2010 8,121,355 03/03/2014 02/28/2020 54.12 — Sanofi-aventis 03/09/2011 874,500 03/10/2015 03/09/2021 50.48 32,448 Sanofi-aventis 03/05/2012 814,050 03/06/2016 03/05/2022 56.44 173,867 Sanofi 03/05/2013 788,725 03/06/2017 03/05/2023 72.19 380,256 Sanofi 03/05/2014 1,009,250 03/06/2018 03/05/2024 73.48 634,265 Sanofi 06/24/2015 435,000 06/25/2019 06/24/2025 89.38 339,964 Sanofi 05/04/2016 402,750 05/05/2020 05/04/2026 75.90 284,250 Sanofi 05/10/2017 378,040 05/11/2021 05/10/2027 88.97 294,220 Sanofi 05/02/2018 220,000 05/03/2022 05/02/2028 65.84 220,000 Sanofi 04/30/2019 220,000 05/02/2023 04/30/2029 76.71 220,000 Total 2,579,270 The exercise of all outstanding stock subscription options would increase shareholders’ equity by approximately €195 million. The exercise of each option results in the issuance of one share. Summary of stock option plans A summary of stock options outstanding at each balance sheet date, and of movements during the relevant periods, is presented below: Number of Weighted average Total Options outstanding at January 1, 2018 7,889,020 60.08 474 Options exercisable 5,812,165 52.93 308 Options granted 220,000 65.84 14 Options exercised (1,192,838) 50.02 (60) Options cancelled (a) (66,609) 82.03 (5) Options outstanding at December 31, 2018 6,849,573 61.81 423 Options exercisable 5,468,214 56.80 311 Options granted 220,000 76.71 17 Options exercised (2,816,123) 53.18 (150) Options cancelled (a) (48,005) 72.84 (3) Options forfeited (383,425) 44.90 (17) Options outstanding at December 31, 2019 3,822,020 70.58 270 Options exercisable 2,650,375 67.14 178 Options exercised (868,655) 59.20 (52) Options cancelled (a) (91,305) 87.73 (8) Options forfeited (282,790) 54.12 (15) Options outstanding at December 31, 2020 2,579,270 75.61 195 Options exercisable 1,845,050 74.51 137 (a) Mainly due to the grantees leaving Sanofi. The table below provides summary information about options outstanding and exercisable as of December 31, 2020: Outstanding Exercisable Range of exercise prices per share Number of Weighted Weighted Number of Weighted From €50.00 to €60.00 per share 206,315 1.02 55.50 206,315 55.50 From €60.00 to €70.00 per share 220,000 7.34 65.84 — — From €70.00 to €80.00 per share 1,518,771 4.08 74.08 1,298,771 73.63 From €80.00 to €90.00 per share 634,184 5.35 89.19 339,964 89.38 Total 2,579,270 1,845,050 D.15.9. Number of shares used to compute diluted earnings per share Diluted earnings per share is computed using the number of shares outstanding plus stock options with dilutive effect and restricted shares. (million) 2020 2019 2018 Average number of shares outstanding 1,253.6 1,249.9 1,247.1 Adjustment for stock options with dilutive effect 0.4 0.8 1.3 Adjustment for restricted shares 6.1 6.4 6.8 Average number of shares used to compute diluted earnings per share 1,260.1 1,257.1 1,255.2 In 2020, 0.6 million stock options were not taken into account in computing diluted earnings per share because they had no dilutive effect, compared with 0.8 million in 2019 and 2.5 million in 2018.

Non-controlling interests

Non-controlling interests	12 Months Ended
	Dec. 31, 2020
Interests In Other Entities [Abstract]
Non-controlling interests	Non-controlling interestsNon-controlling interests did not represent a material component of Sanofi’s consolidated financial statements in the years ended December 31, 2020, 2019 and 2018

Debt, cash and cash equivalents

Debt, cash and cash equivalents and lease liabilities	12 Months Ended
	Dec. 31, 2020
Financial Instruments [Abstract]
Debt, cash and cash equivalents and lease liabilities	Debt, cash and cash equivalents and lease liabilities D.17.1. Debt, cash and cash equivalents Changes in Sanofi's financial position during the period were as follows: (€ million) 2020 2019 2018 Long-term debt 19,745 20,131 22,007 Short-term debt and current portion of long-term debt 2,767 4,554 2,633 Interest rate and currency derivatives used to manage debt 119 (117) (54) Total debt 22,631 24,568 24,586 Cash and cash equivalents (13,915) (9,427) (6,925) Interest rate and currency derivatives used to manage cash and cash equivalents 74 (34) (33) Net debt (a) 8,790 15,107 17,628 (a) Following the first-time application of IFRS 16 effective January 1, 2019, net debt does not include lease liabilities, which amounted to €1,163 million as of December 31, 2020 and € 1,248 million as of December 31, 2019 (see the maturity analysis at Note D.17.2.). “Net debt” is a non-GAAP financial measure used by management and investors to measure Sanofi’s overall net indebtedness. Reconciliation of carrying amount to value on redemption Value on redemption (€ million) Carrying amount at December 31, 2020 Amortized Adjustment December 31, 2020 December 31, 2019 December 31, 2018 Long-term debt 19,745 70 (21) 19,794 20,180 22,071 Short-term debt and current portion of long-term debt 2,767 (2) 2 2,767 4,553 2,613 Interest rate and currency derivatives used to manage debt 119 23 142 (86) (12) Total debt 22,631 68 4 22,703 24,647 24,672 Cash and cash equivalents (13,915) (13,915) (9,427) (6,925) Interest rate and currency derivatives used to manage cash and cash equivalents 74 74 (34) (33) Net debt 8,790 68 4 8,862 15,186 17,714 a) Principal financing transactions during the year The table below shows the movement in total debt during the period: Cash flows from Non-cash items (€ million) December 31, 2019 Repayments New Other Currency Reclassification Other items (a) December 31, 2020 Long-term debt 20,131 — 2,019 — (152) (2,285) 32 19,745 Short-term debt and current portion of long-term debt 4,554 (3,952) — 86 (219) 2,285 13 2,767 Interest rate and currency derivatives used to manage debt (117) — — 196 (14) — 54 119 Total debt 24,568 (3,952) 2,019 282 (385) — 99 22,631 (a) Includes fair value remeasurements. Sanofi carried out one bond issue of €1.5 billion in March 2020 under the Sanofi EMTN program, in two tranches: • €750 million maturing April 2025 and bearing interest at an annual fixed rate of 1.000%; and • €750 million maturing April 2030 and bearing interest at an annual fixed rate of 1.500%. Sanofi also carried out two tap issues in April 2020 of €500 million: • €250 million on the tranche maturing April 2025 bearing interest at an annual fixed rate of 1.000%; and • €250 million on the tranche maturing April 2030 bearing interest at an annual fixed rate of 1.500%. Five bond issues were redeemed in 2020: • €1 billion issued in September 2016, redeemed on maturity on January 13, 2020; • €500 million issued in March 2018, redeemed on maturity on March 21, 2020; • €1 billion issued in March 2018, redeemed on maturity on March 21, 2020; • €1 billion issued in September 2013 and maturing September 2020, redeemed early on June 4, 2020; and • €500 million issued by Genzyme Corp in June 2010, redeemed on maturity on June 15, 2020 On December 8, 2020, Sanofi agreed its first two sustainability-linked revolving credit facilities, involving: • amendments to the existing credit facility expiring December 2021, by adding two extension options each of one year; and • a new syndicated credit facility of €4 billion expiring December 2025 and including two extension options each of one year; this new facility, which took effect on December 8, 2020, replaced an existing €4 billion facility cancelled on the same day. In line with Sanofi's commitment to embed sustainable development in the "Play to Win" strategy, the two revolving credit facilities build in an adjustment mechanism that links the credit spread to the attainment of two sustainable development performance indicators: Sanofi's contribution to polio eradication, and the reduction in Sanofi's carbon footprint. Consequently, as of December 31, 2020 Sanofi had two syndicated credit facilities of €4 billion each available for the purposes of current operations, both of them linked to environmental and social indicators and both them having two one-year extension options. b) Net debt by type, at value on redemption 2020 2019 2018 (€ million) Non- current Current Total Non- Current Total Non- Current Total Bond issues 19,698 2,280 21,978 20,128 4,079 24,207 21,983 2,181 24,164 Other bank borrowings 96 200 296 40 156 196 57 176 233 Finance lease obligations (b) – – – – – – 18 4 22 Other borrowings – 2 2 13 12 25 13 3 16 Bank credit balances – 285 285 – 305 305 – 249 249 Interest rate and currency derivatives used to manage debt 57 85 142 – (86) (86) – (12) (12) Total debt 19,851 2,852 22,703 20,181 4,466 24,647 22,071 2,601 24,672 Cash and cash equivalents – (13,915) (13,915) – (9,427) (9,427) – (6,925) (6,925) Interest rate and currency derivatives used to manage cash and cash equivalents 6 68 74 (6) (28) (34) – (33) (33) Net debt (a) 19,857 (10,995) 8,862 20,175 (4,989) 15,186 22,071 (4,357) 17,714 (a) Following the first-time application of IFRS 16 effective January 1, 2019, net debt does not include lease liabilities (see the maturity schedule in Note D.17.2.). (b) Following the first-time application of IFRS 16 effective January 1, 2019, the finance lease obligation as of that date was reclassified to Lease liabilities . Bond issues carried out by Sanofi under the Euro Medium Term Note (EMTN) program are as follows: Issuer ISIN code Issue date Maturity Annual interest rate Amount (€ million) Sanofi FR0011625433 November 2013 November 2023 2.5 % 1,000 Sanofi FR0012146777 September 2014 March 2022 1.125 % 1,000 Sanofi FR0012146801 September 2014 September 2026 1.75 % 1,510 Sanofi FR0012969020 September 2015 September 2021 0.875 % 500 Sanofi FR0012969038 September 2015 September 2025 1.5 % 750 Sanofi FR0013143997 April 2016 April 2024 0.625 % 600 Sanofi FR0013144003 April 2016 April 2028 1.125 % 700 Sanofi FR0013201621 September 2016 September 2022 - % 850 Sanofi FR0013201639 September 2016 January 2027 0.5 % 1,150 Sanofi FR0013505104 March 2020 April 2025 1 % 1,000 Sanofi FR0013505112 March 2020 April 2030 1.5 % 1,000 Sanofi FR0013324332 March 2018 March 2023 0.5 % 1,750 Sanofi FR0013324340 March 2018 March 2026 1 % 1,500 Sanofi FR0013324357 March 2018 March 2030 1.375 % 2,000 Sanofi FR0013324373 March 2018 March 2038 1.875 % 1,250 Sanofi FR0013409836 March 2019 March 2022 - % 850 Sanofi FR0013409844 March 2019 March 2029 0.875 % 650 Sanofi FR0013409851 March 2019 March 2034 1.25 % 500 Bond issues carried out by Sanofi under the public bond issue program (shelf registration statement) registered with the US Securities and Exchange Commission (SEC) comprise: Issuer ISIN code Issue date Maturity Annual interest rate Amount ($ million) Sanofi US80105NAG07 March 2011 March 2021 4 % 2,000 Sanofi US801060AC87 June 2018 June 2023 3.375 % 1,000 Sanofi US801060AD60 June 2018 June 2028 3.625 % 1,000 The “Other borrowings” line mainly comprises participating shares issued between 1983 and 1987, of which 76,986 remain outstanding, with a nominal amount of €12 million. In order to manage its liquidity needs for current operations, Sanofi has: • a syndicated credit facility of €4 billion, drawable in euros and in US dollars, due to expire on December 5, 2021 following the exercise of a second extension option in November 2016, and with two further one-year extension options still available; and • a syndicated credit facility of €4 billion, drawable in euros and in US dollars, due to expire on December 8, 2025, with two one Sanofi also has a €6 billion Negotiable European Commercial Paper program in France and a $10 billion Commercial Paper program in the United States. During 2020 only the US program was used, with an average drawdown of $1.5 billion and a maximum drawdown of $4.0 billion. As of December 31, 2020, neither of those programs was being utilized. The financing in place as of December 31, 2020 at the level of the holding company (which manages most of Sanofi’s financing needs centrally) is not subject to any financial covenants, and contains no clauses linking fees to the credit rating. c) Debt by maturity, at value on redemption December 31, 2020 Current Non-current (€ million) Total 2021 2022 2023 2024 2025 2026 and later Bond issues 21,978 2,280 2,700 3,569 600 1,750 11,079 Other bank borrowings 296 200 73 6 2 6 9 Finance lease obligations (b) – – – – – – – Other borrowings 2 2 – – – – – Bank credit balances 285 285 – – – – – Interest rate and currency derivatives used to manage debt 142 85 57 – – – – Total debt 22,703 2,852 2,830 3,575 602 1,756 11,088 Cash and cash equivalents (13,915) (13,915) – – – – – Interest rate and currency derivatives used to manage cash and cash equivalents 74 68 6 – – – – Net debt (a) 8,862 (10,995) 2,836 3,575 602 1,756 11,088 (a) Following the first-time application of IFRS 16 effective January 1, 2019, net debt does not include lease liabilities, which amounted to €1,163 million as of December 31, 2020 and €1,248 million as of December 31, 2019 (see the maturity analysis at Note D.17.2.). (b) Following the first-time application of IFRS 16 effective January 1, 2019, the finance lease obligation as of that date was reclassified to Lease liabilities . December 31, 2019 Current Non-current (€ million) Total 2020 2021 2022 2023 2024 2025 and later Bond issues 24,207 4,079 2,284 2,700 3,642 600 10,902 Other bank borrowings 196 156 6 6 23 5 – Finance lease obligations – – – – – – – Other borrowings 25 12 – – – – 13 Bank credit balances 305 305 – – – – – Interest rate and currency derivatives used to manage debt (86) (86) – – – Total debt 24,647 4,466 2,290 2,706 3,665 605 10,915 Cash and cash equivalents (9,427) (9,427) – – – – – Interest rate and currency derivatives used to manage cash and cash equivalents (34) (28) (6) – – – – Net debt 15,186 (4,989) 2,284 2,706 3,665 605 10,915 December 31, 2018 Current Non-current (€ million) Total 2019 2020 2021 2022 2023 2024 and later Bond issues 24,164 2,181 3,936 2,243 1,850 3,622 10,332 Other bank borrowings 233 176 15 3 3 28 8 Finance lease obligations 22 4 3 3 3 4 5 Other borrowings 16 3 — — — — 13 Bank credit balances 249 249 — — — — — Interest rate and currency derivatives used to manage debt (12) (12) — — — — — Total debt 24,672 2,601 3,954 2,249 1,856 3,654 10,358 Cash and cash equivalents (6,925) (6,925) — — — — — Interest rate and currency derivatives used to manage cash and cash equivalents (33) (33) — — — — — Net debt 17,714 (4,357) 3,954 2,249 1,856 3,654 10,358 As of December 31, 2020, the main undrawn confirmed general-purpose credit facilities at holding company level amounted to €8 billion, of which half expires in 2021 and half in 2025. As of December 31, 2020, no single counterparty represented more than 6% of Sanofi’s undrawn confirmed credit facilities. d) Debt by interest rate, at value on redemption The table below splits net debt between fixed and floating rate, and by maturity, as of December 31, 2020. The figures shown are values on redemption, before the effects of derivative instruments: (€ million) Total 2021 2022 2023 2024 2025 2026 and later Fixed-rate debt 21,978 2,280 2,700 3,569 600 1,750 11,079 of which euro 18,703 of which US dollar 3,275 % fixed-rate 97 % Floating-rate debt 584 488 73 6 2 6 9 of which euro 35 of which US dollar 69 % floating-rate 3 % Debt 22,562 2,768 2,773 3,575 602 1,756 11,088 Cash and cash equivalents (13,915) (13,915) – – – – – of which euro (9,192) of which US dollar (4,278) % floating-rate 100 % Net debt 8,647 (11,147) 2,773 3,575 602 1,756 11,088 Sanofi issues debt in two currencies, the euro and the US dollar, and also invests its cash and cash equivalents in those currencies. Sanofi also operates cash pooling arrangements to manage the surplus cash and short-term liquidity needs of foreign subsidiaries located outside the euro zone. To optimize the cost of debt or reduce the volatility of debt and manage its exposure to financial foreign exchange risk, Sanofi uses derivative instruments (interest rate swaps, currency swaps, foreign exchange swaps and forward contracts) that alter the fixed/floating rate split and the currency split of its net debt: (€ million) Total 2021 2022 2023 2024 2025 2026 and later Fixed-rate debt 20,713 2,358 1,357 3,569 600 1,750 11,079 of which euro 17,752 of which US dollar 2,960 % fixed-rate 91 % Floating-rate debt 1,990 494 1,473 6 2 6 9 of which euro 415 of which US dollar 69 of which Japanese yen 215 % floating-rate 9 % Debt 22,703 2,852 2,830 3,575 602 1,756 11,088 Cash and cash equivalents (13,841) (13,847) 6 of which euro (4,442) of which US dollar (6,333) of which Singapore dollar (2,250) % floating-rate 100 % Net debt 8,862 (10,995) 2,836 3,575 602 1,756 11,088 The table below shows the fixed/floating rate split of net debt at value on redemption after taking account of derivative instruments as of December 31, 2019 and December 31, 2018: (€ million) 2019 % 2018 % Fixed-rate debt 21,713 88 % 18,864 76 % Floating-rate debt 2,934 12 % 5,808 24 % Debt 24,647 100 % 24,672 100 % Cash and cash equivalents (9,461) (6,958) Net debt 15,186 17,714 The weighted average interest rate on debt as of December 31, 2020 was 1.6% before derivative instruments and 1.7% after derivative instruments. Cash and cash equivalents were invested as of December 31, 2020 at an average rate of 0.0% before derivative instruments and 0.4% after derivative instruments. The projected full-year sensitivity of net debt to interest rate fluctuations for 2021 is as follows: Change in short-term interest rates Impact on pre-tax net Impact on pre-tax +100 bp 119 – +25 bp 30 – -25 bp (30) – -100 bp (119) – e) Debt by currency, at value on redemption The table below shows net debt by currency at December 31, 2020, before and after derivative instruments contracted to convert the foreign-currency net debt of exposed entities into their functional currency: (€ million) Before derivative instruments After derivative instruments Euro 9,547 13,725 US dollar (933) (3,304) Singapore dollar (1) (2,250) Japanese yen — 214 Chinese yuan renminbi (9) (179) Other currencies 43 656 Net debt 8,647 8,862 The table below shows net debt by currency at December 31, 2019 and 2018, after derivative instruments contracted to convert the foreign currency net debt of exposed entities into their functional currency: (€ million) 2019 2018 Euro 17,691 16,511 US dollar (813) 2,197 Other currencies (1,692) (994) Net debt 15,186 17,714 f) Market value of net debt The market value of Sanofi’s debt, net of cash and cash equivalents and derivatives and excluding accrued interest, is as follows: (€ million) 2020 2019 2018 Market value 10,500 16,370 18,003 Value on redemption 8,862 15,186 17,714 The fair value of debt is determined by reference to quoted market prices at the balance sheet date in the case of quoted instruments (level 1 in the IFRS 7 hierarchy, see Note D.12.), and by reference to the fair value of interest rate and currency derivatives used to manage net debt (level 2 in the IFRS 7 hierarchy, see Note D.12.). g) Future contractual cash flows relating to debt and related derivatives The table below shows the amount of future undiscounted contractual cash flows (principal and interest) relating to debt and to derivative instruments designated as hedges of debt: December 31, 2020 Payments due by period (€ million) Total 2021 2022 2023 2024 2025 2026 and later Debt 24,339 2,943 3,019 3,808 791 1,937 11,841 Principal 22,392 2,622 2,757 3,571 601 1,751 11,090 Interest (a) 1,947 321 262 237 190 186 751 Net cash flows related to derivative instruments 163 135 28 – – – – Total 24,502 3,078 3,047 3,808 791 1,937 11,841 (a) Interest flows are estimated on the basis of forward interest rates applicable as of December 31, 2020. Future contractual cash flows are shown on the basis of the carrying amount in the balance sheet at the reporting date, without reference to any subsequent management decision that might materially alter the structure of Sanofi’s debt or its hedging policy. The tables below show the amount of future undiscounted contractual cash flows (principal and interest) relating to debt and to derivative instruments designated as hedges of debt as of December 31, 2019 and 2018: December 31, 2019 Payments due by period (€ million) Total 2020 2021 2022 2023 2024 2025 and later Debt 26,708 4,775 2,588 2,952 3,862 771 11,760 Principal 24,596 4,417 2,305 2,710 3,646 604 10,914 Interest (a) 2,112 358 283 242 216 167 846 Net cash flows related to derivative instruments (117) (97) (11) (9) Total 26,591 4,678 2,577 2,943 3,862 771 11,760 (a) Interest flows are estimated on the basis of forward interest rates applicable as of December 31, 2019. December 31, 2018 Payments due by period (€ million) Total 2019 2020 2021 2022 2023 2024 and later Debt 26,881 2,855 4,300 2,519 2,088 3,856 11,263 Principal 24,550 2,477 3,955 2,250 1,858 3,653 10,357 Interest (a) 2,331 378 345 269 230 203 906 Net cash flows related to derivative instruments (50) (45) (8) (1) 4 — — Total 26,831 2,810 4,292 2,518 2,092 3,856 11,263 (a) Interest flows are estimated on the basis of forward interest rates applicable as of December 31, 2018. D.17.2. Lease liabilities A maturity analysis of lease liabilities as of December 31, 2020 and 2019 is set forth below: Undiscounted future minimum lease payments (€ million) Total Less than 1 year From 1 to 3 years From 3 to 5 years More than 5 years Discounting effect Total lease liabilities as of December 31, 2020 1,163 247 357 225 482 (148) Total lease liabilities as of December 31, 2019 1,248 272 422 232 540 (218)

Liabilities related to business

Liabilities related to business combinations and to non-controlling interests	12 Months Ended
	Dec. 31, 2020
Business Combinations 1 [Abstract]
Liabilities related to business combinations and to non-controlling interests	Liabilities related to business combinations and to non-controlling interests For a description of the nature of the liabilities reported in the line item Liabilities related to business combinations and to non-controlling interests , refer to Note B.8.5. The principal acquisitions are described in Notes D.1. and D.2. The liabilities related to business combinations and to non-controlling interests shown in the table below are level 3 instruments under the IFRS 7 fair value hierarchy (see Note D.12.) except for the CVRs issued in connection with the acquisition of Genzyme, which are level 1 instruments. Movements in liabilities related to business combinations and to non-controlling interests are shown below: (€ million) Liabilities related to non-controlling interests (a) CVRs issued in connection with the acquisition of Genzyme (b) Bayer contingent consideration arising from the acquisition of Genzyme MSD Other Total (c) Balance at January 1, 2018 92 75 701 420 81 1,369 New transactions (e) — — — — 228 228 Payments made (70) — (147) (57) (55) (329) Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount) (d) — 19 (109) 50 3 (37) Other movements — — — — 24 24 Currency translation differences — 5 27 (3) 20 49 Balance at December 31, 2018 22 99 472 410 301 1,304 Payments made — — (113) (69) (55) (237) Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount) (d) — 49 (214) 38 81 (46) Other movements (22) (153) — — (73) (248) Currency translation differences — 5 11 6 5 27 Balance at December 31, 2019 — — 156 385 259 800 Payments made — — (42) (78) (2) (122) Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount) (d) — — 9 9 (53) (35) Other movements — — (8) — (2) (10) Currency translation differences — — (11) (4) (13) (28) Balance at December 31, 2020 — — 104 312 189 605 (a) Includes put options granted to non-controlling interests expired in 2019, and a commitment to a future buyout of non-controlling interests held by BMS (the payment relating to that buyout had been made as of December 31, 2018: see Note C.2.). (b) Based on the quoted market price per CVR of $0.72 as of October 30, 2019 and $0.48 as of December 31, 2018. The CVR agreement was terminated in March 2020 following signature of a litigation settlement agreement. (c) Portion due after more than one year: €387 million as of December 31, 2020 (€508 million as of December 31, 2019 and €963 million as of December 31, 2018); portion due within less than one year: €218 million as of December 31, 2020 (€292 million as of December 31, 2019 and €341 million as of December 31, 2018). (d) Amounts reported within the income statement line item Fair value remeasurement of contingent consideration , and mainly comprising unrealized gains and losses. (e) Includes €226 million for contingent consideration liabilities in favor of True North Therapeutics and €2 million of liabilities owed to Bioverativ employees at the acquisition date. As of December 31, 2020, Liabilities related to business combinations and to non-controlling interests mainly comprised: • A liability arising from the acquisition of True North Therapeutics by Bioverativ. The former shareholders of True North Therapeutics are entitled to milestone payments contingent on the attainment of development, registration and sales objectives; the fair value of the resulting liability was measured at $197 million as of December 31, 2020, compared with $255 million as of December 31, 2019 and $192 million as of December 31, 2018. That fair value is determined based on the contractual terms and on development and sales projections which have been weighted to reflect the probability of success, and discounted. If the discount rate were to fall by one percentage point, the fair value of the True North contingent consideration liability would increase by approximately 1%. • The Bayer contingent consideration liability arising from Sanofi's acquisition of Genzyme in 2011. As of December 31, 2020, Bayer was still entitled to receive the following potential payments: – a percentage of sales of alemtuzumab up to a maximum of $1,250 million or over a maximum period of 10 years, whichever is achieved first; – milestone payments based on specified levels of worldwide sales of alemtuzumab beginning in 2021, unless Genzyme exercises its right to buy out those milestone payments by making a one-time payment not exceeding $900 million. The fair value of this liability was measured at €104 million as of December 31, 2020, compared with €156 million as of December 31, 2019 and €472 million as of December 31, 2018. The fair value of the Bayer liability is determined by applying the contractual terms to sales projections which have been weighted to reflect the probability of success, and discounted. If the discount rate were to fall by one percentage point, the fair value of the Bayer liability would increase by approximately 1%. • The MSD contingent consideration liability arising from the 2016 acquisition of the Sanofi Pasteur activities carried on within the former Sanofi Pasteur MSD joint venture, which amounted to €312 million as of December 31, 2020, €385 million as of December 31, 2019 and €410 million as of December 31, 2018 (see Note D.12.). The fair value of this contingent consideration is determined by applying the royalty percentage stipulated in the contract to discounted sales projections. If the discount rate were to fall by one percentage point, the fair value of the MSD contingent consideration liability would increase by approximately 2%. The table below sets forth the maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests: December 31, 2020 Total Payments due by period (€ million) Less than From 1 to From 3 to More than Commitments relating to contingent consideration in connection with business combinations (a) 1,043 228 351 192 272 (a) Includes €0.4 billion for the Bayer contingent consideration and €0.4 billion for the MSD contingent consideration. The nominal amount of contingent consideration was €3,503 million as of December 31, 2019 and €3,638 million as of December 31, 2018. The reduction in commitments during 2020 mainly reflects the termination of the CVR agreement in March 2020.

Provisions, income tax liabilit

Provisions, income tax liabilities and other liabilities	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Provisions, income tax liabilities and other liabilities	Provisions, income tax liabilities and other liabilities The line item Non current provisions and other non-current liabilities comprises the following: (€ million) 2020 2019 2018 Provisions 7,219 7,353 6,883 Other non-current liabilities (a) 317 288 323 Total 7,536 7,641 7,206 (a) Includes derivative financial instruments: €92 million as of December 31, 2020, €10 million as of December 31, 2019, €7 million as of December 31, 2018. Other current liabilities are described in Note D.19.5. The table below sets forth movements in non-current provisions for the reporting periods presented: (€ million) Provisions for Provisions Restructuring Other Total Balance at January 1, 2018 3,959 750 514 1,975 7,198 Changes in scope of consolidation (6) (2) — 37 29 Increases in provisions 251 (a) 93 387 306 (b) 1,037 Provisions utilized (529) (a) (101) (3) (160) (793) Reversals of unutilized provisions (36) (a) (5) (15) (190) (246) Transfers (22) 10 (251) (26) (289) Net interest related to employee benefits, and unwinding of discount 70 4 — 24 98 Unrealized gains and losses — — — — — Currency translation differences 36 12 — 2 50 Actuarial gains and losses on defined-benefit plans (c) (201) — — — (201) Balance at December 31, 2018 3,522 761 632 1,968 6,883 Changes in scope of consolidation (1) — — — (1) Increases in provisions 213 (a) 189 393 554 (b) 1,349 Provisions utilized (285) (a) (102) (3) (132) (522) Reversals of unutilized provisions (209) (a) (3) (15) (511) (d) (738) Transfers 92 (3) (411) 168 (154) Net interest related to employee benefits, and unwinding of discount 83 5 3 18 109 Unrealized gains and losses — — — — — Currency translation differences 35 8 1 6 50 Actuarial gains and losses on defined-benefit plans (c) 377 — — — 377 Balance at December 31, 2019 3,827 855 600 2,071 7,353 Changes in scope of consolidation (3) — — 8 5 Increases in provisions 253 (a) 169 688 369 1,479 Provisions utilized (566) (a) (109) (5) (113) (793) Reversals of unutilized provisions (233) (a) (5) (42) (245) (525) Transfers 12 — (369) (64) (421) Net interest related to employee benefits, and unwinding of discount 57 2 1 8 68 Unrealized gains and losses — — — — — Currency translation differences (117) (33) (5) (59) (214) Actuarial gains and losses on defined-benefit plans (c) 267 — — — 267 Balance at December 31, 2020 3,497 879 868 1,975 7,219 (a) In the case of “Provisions for pensions and other post-employment benefits”, the “Increases in provisions” line corresponds to rights vesting in employees during the period, and past service cost; the “Provisions utilized” line corresponds to contributions paid into pension funds, and plan settlements; and the “Reversals of unutilized provisions” line corresponds to plan curtailments, settlements and amendments.. (b) Amounts charged during the period include changes to estimates of future expenditures on environmental risks. (c) Amounts recognized in Other comprehensive income (see Note D.15.7.). (d) This amount mainly comprises a reversal of a provision resulting from a settlement of litigation (see Note D.28.). D.19.1. Provisions for pensions and other post-employment benefits Sanofi offers its employees pension plans and other post-employment benefit plans. The specific features of the plans (benefit formulas, fund investment policy and fund assets held) vary depending on the applicable laws and regulations in each country where the employees work. These employee benefits are accounted for in accordance with IAS 19 (see Note B.23.). Sanofi’s pension obligations in four major countries represented approximately 89% of the total value of the defined-benefit obligation and approximately 87% of the total value of plan assets as of December 31, 2020. The features of the principal defined-benefit plans in each of those four countries are described below. France Lump-sum retirement benefit plans All employees working for Sanofi in France are entitled on retirement to a lump-sum payment, the amount of which depends both on their length of service and on the rights guaranteed by collective and internal agreements. The employee’s final salary is used in calculating the amount of these lump-sum retirement benefits. These plans represent approximately 41% of Sanofi’s total obligation in France. Defined-benefit pension plans These plans provide benefits from the date of retirement. Employees must fulfil a number of criteria to be eligible for these benefits. All of these plans are now closed, the only plan still open to new entrants having been closed in 2019. These plans represent approximately 59% of Sanofi’s total obligation in France. Germany Top-up defined-benefit pension plan The benefits offered under this pension plan are wholly funded by the employer (there are no employee contributions) via a Contractual Trust Agreement (CTA), under which benefits are estimated on the basis of a career average salary. Employees are entitled to receive an annuity under this plan if their salary exceeds the social security ceiling. The amount of the pension is calculated by reference to a range of vesting rates corresponding to salary bands. The plan also includes disability and death benefits. This plan represents approximately 65% of Sanofi’s total obligation in Germany. Sanofi-Aventis plus (SAV plus) A top-up pension plan (SAV plus) replaced a previous top-up defined-benefit plan. New entrants joining the plan after April 1, 2015 contribute to a defined-contribution plan that is partially funded via the company’s CTA. All employees whose salary exceeds the social security ceiling are automatically covered by the plan. The employer’s contribution is 15% of the amount by which the employee’s salary exceeds the social security ceiling. Multi-employer plan (Pensionskasse) This is a defined-benefit plan treated as a defined-contribution plan, in accordance with the accounting policies described in Note B.23. Currently, contributions cover the level of annuities. Only the portion relating to the future revaluation of the annuities is included in the defined-benefit pension obligation. The obligation relating to this revaluation amounted to €773 million as of December 31, 2020, versus €694 million as of December 31, 2019 and €673 million as of December 31, 2018. This plan represents approximately 22% of Sanofi’s total defined-benefit obligation in Germany. United States Defined-benefit pension plans In the United States, there are two types of defined-benefit plan: • “Qualified” plans within the meaning of the Employee Retirement Income Security Act of 1974 (ERISA), which provide guaranteed benefits to eligible employees during retirement, and in the event of death or disability. Employees can elect to receive a reduced annuity, in exchange for an annuity to be paid in the event of their death to a person designated by them. An annuity is also granted under the plan if the employee dies before retirement age. Eligible employees do not pay any contributions. These plans are closed to new entrants, and the vesting of rights for future service periods is partially frozen. These plans represent approximately 53% of Sanofi’s total obligation in the United States. • “Non-qualified” plans within the meaning of ERISA provide top-up retirement benefits to some eligible employees depending on the employee’s level of responsibility and subject to a salary cap. These plans represent approximately 12% of Sanofi’s total obligation in the United States. Healthcare cover and life insurance Sanofi companies provide some eligible employees with healthcare cover and life insurance during the retirement period (the company’s contributions are capped at a specified level). These plans represent approximately 35% (or €734 million) of Sanofi’s total obligation and 4% (or €44 million) of total plan assets in the United States. United Kingdom Defined-benefit pension plans Sanofi operates a number of pension plans in the United Kingdom that reflect past acquisitions. The most significant arrangements are defined-benefit plans that have been closed since October 1, 2015. With effect from that date, employees can no longer pay into these plans. Under these defined-benefit plans, an annuity is paid from the retirement date. This annuity is calculated on the basis of the employee’s length of service as of September 30, 2015, and of the employee’s final salary (or salary on the date he or she leaves Sanofi). The rates used for the vesting of rights vary from member to member. For most members, rights vest at the rate of 1.25% or 1.50% of final salary for each qualifying year of service giving entitlement. The notional retirement age varies according to the category to which the member belongs, but in most cases retirement is at age 65. Members may choose to retire before or after the notional retirement age (60 years), in which case the amount of the annual pension is adjusted to reflect the revised estimate of the length of the retirement phase. Pensions are usually indexed to the Retail Price Index (RPI). Members paid a fixed-percentage contribution into their pension plan (the percentage varied according to the employee category), and the employer topped up the contribution to the required amount. These plans represent approximately 100% of Sanofi’s total obligation in the United Kingdom. For service periods subsequent to October 1, 2015, employees belong to a new defined-contribution plan. Actuarial assumptions used to measure Sanofi’s obligations Actuarial valuations of Sanofi’s benefit obligations were computed by management with assistance from external actuaries as of December 31, 2020, 2019 and 2018. Those calculations were based on the following financial and demographic assumptions: 2020 2019 2018 France Germany USA UK France Germany USA UK France Germany USA UK Discount rate (a)/(b) 0.00% or 0.55% 0.00% or 0.55% 2.40 % 1.35 % 0.25% or 0.75% 0.25% or 0.75% 3.00 % 2.00 % 1.25% or 1.75% 1.25% or 1.75% 4.00 % 3.00 % General inflation rate (c) 1.45 % 1.45 % 2.00 % 2.95 % 1.30 % 1.30 % 2.00 % 2.85 % 1.50 % 1.50 % 2.00 % 3.10 % Pension benefit 1.45% 1.45 % — 2.85 % 1.25% to 2.25% 1.30 % — 2.80 % 1.25% to 2.25% 1.50 % — 3.00 % Healthcare cost — — (d) 3.50% to 4.50% 4.45 % (e) 2.00 % — (d) 5.52 % 4.35 % 2.00 % — (d) 5.66 % 1.50 % Retirement age 62 to 67 62 55 to70 60 to 65 62 to 67 62 55 to 70 60 to 65 62 to 67 62 55 to 70 60 to 65 Mortality table TGH/ Heubeck RP2012 Proj. SAPS TGH/ Heubeck RP2014 SAPS TGH/ Heubeck RP2014 SAPS (a) The discount rates used were based on market rates for high quality corporate bonds with a duration close to that of the expected benefit payments under the plans. The benchmarks used to determine discount rates were the same for all periods presented. (b) The rate depends on the duration of the plan (0 to 7 years, 7 to 10 years, or more than 10 years). (c) Inflation for the euro zone is determined using a multi-criterion method. (d) No post-employment healthcare benefits are provided in Germany. (e) Healthcare cost inflation rate in the United Kingdom of 1.50% above the general inflation rate. Weighted average duration of obligation for pensions and other long-term benefits in principal countries The table below shows the duration of Sanofi’s obligations in the principal countries: 2020 2019 2018 (years) France Germany USA UK France Germany USA UK France Germany USA UK Weighted average duration 13 16 16 18 13 15 14 17 13 15 13 17 Sensitivity analysis The table below shows the sensitivity of Sanofi’s obligations for pensions and other post-employment benefits to changes in key actuarial assumptions: (€ million) Pensions and other post-employment benefits, by principal country Measurement of defined-benefit obligation Change in France Germany USA UK Discount rate -0.50 % +140 +272 +171 +337 General inflation rate +0.50 % +64 +377 +1 +216 Pension benefit indexation +0.50 % +71 +367 — +160 Healthcare cost inflation rate +0.50 % — — +14 — Mortality table +1 year +41 +83 +55 +154 The table below reconciles the net obligation in respect of Sanofi’s pension and other post-employment benefit plans with the amounts recognized in the consolidated financial statements: Pensions and other post-employment benefits (€ million) 2020 2019 2018 Measurement of the obligation: Beginning of period 13,322 12,055 13,012 Current service cost 218 199 231 Interest cost 194 293 260 Actuarial losses/(gains) due to changes in demographic assumptions 41 (61) 204 Actuarial losses/(gains) due to changes in financial assumptions 946 1,481 (841) Actuarial losses/(gains) due to experience adjustments (24) (119) (14) Plan amendments, curtailments or settlements not specified in the terms of the plan (a) (945) (259) (96) Plan settlements specified in the terms of the plan (75) (78) (83) Benefits paid (545) (504) (647) Changes in scope of consolidation and transfers (12) 13 (46) Currency translation differences (443) 302 75 Obligation at end of period 12,677 13,322 12,055 Fair value of plan assets: Beginning of period 9,651 8,610 9,106 Interest income on plan assets 138 211 190 Difference between actual return and interest income on plan assets 696 926 (450) Administration costs (14) (7) (8) Plan settlements specified in the terms of the plan (75) (78) (83) Plan settlements not specified in the terms of the plan (739) (64) (78) Contributions from plan members 6 6 6 Employer’s contributions 490 250 392 Benefits paid (469) (470) (510) Changes in scope of consolidation and transfers — — 6 Currency translation differences (326) 267 39 Fair value of plan assets at end of period 9,358 9,651 8,610 Net amount shown in the balance sheet: Net obligation 3,319 3,671 3,445 Effect of asset ceiling 1 1 — Net amount shown in the balance sheet at end of period 3,320 3,672 3,445 Amounts recognized in the balance sheet: Pre-funded obligations (see Note D.7.) (177) (155) (77) Obligations provided for 3,497 3,827 3,522 Net amount recognized at end of period 3,320 3,672 3,445 Benefit cost for the period: Current service cost 218 199 231 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (a) (206) (195) (18) Net interest (income)/cost 57 83 70 Contributions from plan members (7) (6) (6) Administration costs and taxes paid during the period 14 7 8 Expense recognized directly in profit or loss 76 88 285 Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses) 267 377 (201) Expense/(gain) for the period 343 465 84 (a) For 2019, this line mainly comprises the favorable impact of the amendment to the remaining top-up pension plan, following the application of the Pacte law in France. For 2020, it mainly comprises a reduction in post-employment benefit liabilities following the announcement of voluntary redundancy programs, primarily in Europe. The tables below show Sanofi’s net liability in respect of pension plans and other post-employment benefits by geographical region: (€ million) Pensions and other post-employment benefits by geographical region December 31, 2020 France Germany USA UK Other Total Measurement of obligation 1,999 3,580 2,091 3,561 1,446 12,677 Fair value of plan assets 906 2,661 1,077 3,536 1,178 9,358 Effect of asset ceiling — — — — 1 1 Net amount shown in the balance sheet at end of period 1,093 919 1,014 25 269 3,320 (€ million) Pensions and other post-employment benefits by geographical region December 31, 2019 France Germany USA UK Other Total Measurement of obligation 2,077 3,470 2,948 3,388 1,439 13,322 Fair value of plan assets 956 2,516 1,774 3,258 1,147 9,651 Effect of asset ceiling — — — — 1 1 Net amount shown in the balance sheet at end of period 1,121 954 1,174 130 293 3,672 (€ million) Pensions and other post-employment benefits by geographical region December 31, 2018 France Germany USA UK Other Total Measurement of obligation 2,091 3,262 2,597 2,858 1,247 12,055 Fair value of plan assets 931 2,217 1,622 2,862 978 8,610 Net amount shown in the balance sheet at end of period 1,160 1,045 975 (4) 269 3,445 The table below shows the fair value of plan assets relating to Sanofi’s pension and other post-employment plans, split by asset category: 2020 2019 2018 Securities quoted in an active market 94.8 % 87.4 % 99.2 % Cash and cash equivalents 3.5 % 1.8 % 1.4 % Equity instruments 24.8 % 22.6 % 22.3 % Bonds and similar instruments 59.9 % 55.8 % 66.5 % Real estate 3.4 % 3.8 % 4.2 % Commodities 0.9 % 0.9 % 0.7 % Other 2.3 % 2.5 % 4.1 % Other securities 5.2 % 12.6 % 0.8 % Hedge funds 0.4 % — % — % Insurance policies 4.8 % 12.6 % 0.8 % Total 100.0 % 100.0 % 100.0 % Sanofi has a long-term objective of maintaining or increasing the extent to which its pension obligations are covered by assets. To this end, Sanofi uses an asset-liability management strategy, matching plan assets to its pension obligations. This policy aims to ensure the best fit between the assets held on the one hand, and the associated liabilities and expected future payments to plan members on the other. To meet this aim, Sanofi operates a risk monitoring and management strategy (mainly focused on interest rate risk and inflation risk), while investing a growing proportion of assets in high-quality bonds with comparable maturities to those of the underlying obligations and in contracts entered into with leading insurance companies to fund certain post-employment benefit obligations. The tables below show the service cost for Sanofi’s pension and other post-employment benefit plans, by geographical region: (€ million) Pensions and other post-employment benefits by geographical region Service cost for 2020 France Germany USA UK Other Total Current service cost 62 49 51 — 56 218 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (94) 10 (123) — 1 (206) Net interest cost/(income) including administration costs and taxes paid during the period 9 13 34 5 10 71 Contributions from plan members — — — — (7) (7) Expense/(gain) recognized directly in profit or loss (23) 72 (38) 5 60 76 Remeasurement of net defined-benefit (asset)/ liability (actuarial gains and losses) 24 121 22 115 (15) 267 Expense/(gain) for the period 1 193 (16) 120 45 343 (€ million) Pensions and other post-employment benefits by geographical region Service cost for 2019 France Germany USA UK Other Total Current service cost 62 42 42 — 53 199 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (193) 13 (12) (2) (1) (195) Net interest cost/(income) including administration costs and taxes paid during the period 20 17 40 2 11 90 Contributions from plan members — — — — (6) (6) Expense/(gain) recognized directly in profit or loss (111) 72 70 — 57 88 Remeasurement of net defined-benefit (asset)/ liability (actuarial gains and losses) 89 (4) 148 133 11 377 Expense/(gain) for the period (22) 68 218 133 68 465 (€ million) Pensions and other post-employment benefits by geographical region Service cost for 2018 France Germany USA UK Other Total Current service cost 78 51 46 — 56 231 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (5) (20) 3 5 (1) (18) Net interest cost/(income) including administration costs and taxes paid during the period 17 12 35 4 10 78 Contributions from plan members — — — — (6) (6) Expense/(gain) recognized directly in profit or loss 90 43 84 9 59 285 Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses) (155) (13) (38) 7 (2) (201) Expense/(gain) for the period (65) 30 46 16 57 84 An analysis of the “Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)” line in the preceding tables is set forth below: (€ million) 2020 2019 2018 France Germany USA UK France Germany USA UK France Germany USA UK Actuarial gains/(losses) arising during the period (a) (24) (121) (22) (115) (89) 5 (148) (133) 155 13 38 (7) Comprising: Gains/(losses) on experience adjustments (b) 26 76 214 341 149 331 210 242 21 (154) (131) (118) Gains/(losses) 20 — (42) (14) — — — 63 (7) (67) 7 (144) Gains/(losses) (70) (197) (194) (442) (238) (326) (358) (438) 141 234 162 255 (a) Gains and losses arising from changes in assumptions are due primarily to changes in the discount rate. (b) Experience adjustments are mainly due to the effect of trends in the financial markets on plan assets. The net pre-tax actuarial loss (excluding investments accounted for using the equity method) recognized directly in equity is presented below: (€ million) 2020 2019 2018 Net pre-tax actuarial loss (3,471) (3,207) (2,834) The present value of Sanofi’s obligations in respect of pension and other post-employment benefit plans at the end of each reporting period is shown below: (€ million) 2020 2019 2018 Present value of wholly or partially funded obligations in respect of pension and other post-employment benefit plans 11,543 12,057 10,995 Present value of unfunded obligations 1,134 1,265 1,060 Total 12,677 13,322 12,055 The total expense for pensions and other post-employment benefits (€76 million in 2020) is allocated between income statement line items as follows: (€ million) 2020 2019 2018 Cost of sales 75 46 67 Research and development expenses 62 25 77 Selling and general expenses (34) (22) 84 Other operating (income)/expenses, net (18) (3) (21) Restructuring costs (66) (41) 8 Financial expenses 57 83 70 Total 76 88 285 The estimated amounts of employer’s contributions to plan assets in 2021 are as follows: (€ million) France Germany USA UK Other Total Employer’s contributions in 2021 (estimate): 2021 — — — 3 39 42 The table below shows the expected timing of benefit payments under pension and other post-employment benefit plans for the next ten years: (€ million) France Germany USA UK Other Total Estimated future benefit payments: 2021 145 186 95 119 62 607 2022 64 190 88 122 53 517 2023 74 195 88 126 56 539 2024 84 199 91 130 60 564 2025 80 203 85 134 58 560 2026 to 2029 529 1,024 439 734 340 3,066 The table below shows estimates as of December 31, 2020 for the timing of future payments in respect of unfunded pension and other post-employment benefit plans: Total Payments due by period (€ million) Less than 1 year 1 to 3 to More than Estimated payments 1,134 61 99 102 872 D.19.2. Restructuring provisions The table below shows movements in restructuring provisions classified in non-current and current liabilities: (€ million) 2020 2019 2018 Balance, beginning of period 1,390 1,572 1,086 Of which: • Classified in non-current liabilities 600 632 514 • Classified in current liabilities 790 940 572 Change in provisions recognized in profit or loss for the period 767 760 1,035 Provisions utilized (663) (897) (605) Transfers 20 (51) 54 Unwinding of discount 1 3 — Currency translation differences (16) 3 2 Balance, end of period 1,499 1,390 1,572 Of which: • Classified in non-current liabilities 868 600 632 • Classified in current liabilities 631 790 940 Provisions for employee termination benefits as of December 31, 2020 amounted to €1,260 million (compared with €1,125 million as of December 31, 2019 and €895 million as of December 31, 2018). The provisions apply mainly to France, and relate to various voluntary redundancy programs: • collectively-agreed termination programs involving a number of legal entities that were announced at the end of June 2020 as part of the rollout of the "Play to Win" strategy, and that included an end-of-career paid leave plan and an end-of-career transition plan, plus a voluntary redundancy program announced by Sanofi-Aventis Recherche & Développement in connection with the reorganization of R&D operations in France; • programs announced in 2019 relating to (i) R&D (Sanofi-Aventis Recherche & Développement), and (ii) sales forces (the "SAF 2019" plan implemented by Sanofi-Aventis France); • collectively-agreed termination programs announced in 2018 relating to reorganization of support functions ("Horizon 2020" plan); • the program announced in 2016 in connection with Sanofi's new strategic roadmap plan (the "Forward" plan). The remainder of the provision for France comprises termination benefits associated with previously-announced programs (early retirement plans and end-of-career transition plans). The provision includes the present values of: • gross annuities for self-funded plans; • employer’s social security charges on early retirement annuities for all plans (outsourced and self-funded); • the levy charged on those annuities under the “Fillon” law (only for plans with termination of employment contracts). The average residual holding periods under these plans were 1.99 years, 1.72 years and 2.03 years as of December 31, 2020, 2019 and 2018, respectively. The main other countries covered by restructuring provisions are Germany and the United States. The timing of future termination benefit payments is as follows: December 31, 2020 Total Benefit payments by period (€ million) Less than 1 to 3 to More than Employee termination benefits • France 889 295 457 124 13 • Other countries 371 195 149 18 9 Total 1,260 490 606 142 22 December 31, 2019 Benefit payments by period (€ million) Total Less than 1 to 3 to More than Employee termination benefits • France 694 314 268 110 2 • Other countries 431 343 79 6 3 Total 1,125 657 347 116 5 December 31, 2018 Benefit payments by period (€ million) Total Less than 1 to 3 to More than Employee termination benefits • France 623 302 242 71 8 • Other countries 272 187 62 6 17 Total 895 489 304 77 25 Restructuring provisions as of December 31, 2020 also include €110 million (versus €154 million as of December 31, 2019) relating to the transfer to Evotec of the infectious diseases early-stage R&D portfolio and research unit. Restructuring provisions as of December 31, 2019 and December 31, 2018 also included amounts of €22 million and €68 million, respectively, relating to a five-year commitment to Evotec regarding the Toulouse R&D site in France; that commitment expired in 2020. D.19.3. Other provisions Other provisions include provisions for risks and litigation relating to environmental, tax, commercial and product liability matters. (€ million) 2020 2019 2018 Environmental risks 713 737 680 Product liability risks, litigation and other 1,262 1,334 1,288 Total 1,975 2,071 1,968 Provisions for environmental risks relate primarily to contingencies arising from business divestitures, and include remediation costs relating to such environmental risks. Identified environmental risks are covered by provisions estimated on the basis of the costs Sanofi believes it will be obliged to meet over a period not exceeding (other than in exceptional cases) 30 years. Sanofi expects that €189 million of those provisions will be utilized in 2021, and €234 million over the period from 2022 through 2025. “Product liability risks, litigation and other” mainly comprises provisions for risks relating to product liability (including IBNR provisions as described in Note B.12.), government investigations, regulatory or antitrust law claims, contingencies arising from business divestitures (other than environmental risks), and remediation costs related to leases. The main pending legal and arbitral proceedings and government investigations are described in Note D.22. A full risk and litigation assessment is performed with the assistance of Sanofi’s legal advisers, and provisions are recorded as required by circumstances in accordance with the principles described in Note B.12. D.19.4. Non-current income tax liabilities Non-current income tax liabilities amounted to €1,733 million as of December 31, 2020 (versus €1,680 million as of December 31, 2019 and €1,407 million as of December 31, 2018). The estimated tax charge on deemed repatriation attributable to the accumulated earnings of non-US operations and payable over 8 years is recognized as a liability, and amounted to €894 million in 2020 versus €974 million in 2019 and €952 million 2018. The resulting residual tax charge generated a non-current liability of €569 million as of December 31, 2020, versus €649 million in 2019 and €635 million in 2018. In accordance with Sanofi accounting policies, this non-current liability is not discounted. Non-current income tax liabilities include uncertainties over income tax treatments amounting to €1,164 million as of December 31, 2020, versus €1,031 million as of December 31, 2019 and €772 million as of December 31, 2018. D.19.5. Current provisions and other current liabilities Current provisions and other current liabilities comprise the following: (€ million) 2020 2019 2018 Taxes payable, other than corporate income taxes 347 361 393 Employee-related liabilities 2,042 1,978 1,989 Restructuring provisions (see Note D.19.2.) 631 790 940 Interest rate derivatives (see Note D.20.) — 2 — Currency derivatives (see Note D.20.) 205 87 90 Amounts payable for acquisitions of non-current assets 467 413 497 Customer contract liabilities (a) 252 — — Other current liabilities (b) 6,188 6,072 5,060 Total 10,132 9,703 8,969 (a) See Note A.7. , "Agreements relating to the recombinant Covid-19 vaccine candidate developed by Sanofi in collaboration with GSK" . (b) As of December 31, 2019, the "Other current liabilities" line included $315 million deposited by Sanofi in an escrow account, the release of which occurred in March 2020 following the signature of a settlement agreement in the CVR litigation between Sanofi and the Trustee. “Other current liabilities” includes provisions for customer rebates and returns, and for discounts and rebates granted to healthcare authorities and governmental programs (see Note D.23.).

Derivative financial instrument

Derivative financial instruments and market risks	12 Months Ended
	Dec. 31, 2020
Financial Instruments [Abstract]
Derivative financial instruments and market risks	Derivative financial instruments and market risks The table below shows the fair value of derivative instruments as of December 31, 2020, 2019 and 2018: (€ million) Non-current assets Current Total Non-current Current Total Market value at December 31, 2020 (net) Market value at December 31, 2019 (net) Market value at December 31, 2018 (net) Currency derivatives — 58 58 (62) (205) (267) (209) 103 44 operating — 26 26 — (19) (19) 7 (15) 7 financial — 32 32 (62) (186) (248) (216) 118 37 Interest rate derivatives 24 — 24 (4) — (4) 20 27 42 Equity derivatives — — — (26) — (26) (26) (4) Total 24 58 82 (92) (205) (297) (215) 126 86 Objectives of the use of derivative financial instruments Sanofi uses derivative instruments to manage operating exposure to movements in exchange rates, and financial exposure to movements in interest rates and exchange rates (where the debt or receivable is not contracted in the functional currency of the borrower or lender entity). On occasion, Sanofi uses equity derivatives in connection with the management of its portfolio of equity investments. Sanofi performs periodic reviews of its transactions and contractual agreements in order to identify any embedded derivatives, which are accounted for separately from the host contract in accordance with IFRS 9. Sanofi had no material embedded derivatives as of December 31, 2020, 2019 or 2018. Counterparty risk For a description of counterparty risk, refer to "–Item 11. – Quantitative and Qualitative Disclosures about Market Risk". a) Currency derivatives used to manage operating risk exposures For a description of Sanofi's objectives, policies and procedures for the management of operating foreign exchange risk, refer to "–Item 11. – Quantitative and Qualitative Disclosures about Market Risk". The table below shows operating currency hedging instruments in place as of December 31, 2020, with the notional amount translated into euros at the relevant closing exchange rate: December 31, 2020 Of which derivatives designated as Of which derivatives not (€ million) Notional Fair Notional Fair Of which Notional Fair value Forward currency sales 3,477 7 — — — 3,477 7 of which US dollar 1,367 10 — — — 1,367 10 of which Chinese yuan renminbi 521 2 — — — 521 2 of which Singapore dollar 287 (1) — — — 287 (1) of which Japanese yen 143 1 — — — 143 1 of which Mexican peso 121 — — — — 121 — Forward currency purchases 1,932 — — — — 1,932 — of which US dollar 580 (1) — — — 580 (1) of which Singapore dollar 571 (1) — — — 571 (1) of which Chinese yuan renminbi 286 1 — — — 286 1 of which Russian rouble 61 — — — — 61 — of which Japanese yen 55 — — — — 55 — Total 5,409 7 — — — 5,409 7 The table below shows operating currency hedging instruments in place as of December 31, 2019, with the notional amount translated into euros at the relevant closing exchange rate: December 31, 2019 Of which derivatives designated as Of which derivatives not (€ million) Notional Fair Notional Fair Of which Notional Fair value Forward currency sales 3,372 (10) – – – 3,372 (10) of which US dollar 1,186 3 – – – 1,186 3 of which Chinese yuan renminbi 447 — – – – 447 — of which Singapore dollar 410 — – – – 410 — of which Russian rouble 184 (3) – – – 184 (3) of which Saudi riyal 133 1 – – – 133 1 Forward currency purchases 1,835 (5) – – – 1,835 (5) of which US dollar 602 (6) – – – 602 (6) of which Singapore dollar 525 1 – – – 525 1 of which Chinese yuan renminbi 130 — – – – 130 — of which Hungarian forint 60 — – – – 60 — of which Russian rouble 49 — – – – 49 — Total 5,207 (15) – – – 5,207 (15) The table below shows operating currency hedging instruments in place as of December 31, 2018, with the notional amount translated into euros at the relevant closing exchange rate: December 31, 2018 Of which derivatives Of which derivatives not eligible for hedge accounting (€ million) Notional Fair Notional Fair Of which Notional Fair value Forward currency sales 4,002 — — — — 4,002 — of which US dollar 1,723 (7) — — — 1,723 (7) of which Singapore dollar 652 1 — — — 652 1 of which Chinese yuan renminbi 451 (1) — — — 451 (1) of which Saudi riyal 100 1 — — — 100 1 of which Russian rouble 88 5 — — — 88 5 Forward currency purchases 2,036 7 — — — 2,036 7 of which US dollar 514 8 — — — 514 8 of which Singapore dollar 500 1 — — — 500 1 of which Japanese yen 197 3 — — — 197 3 of which Chinese yuan renminbi 163 (1) — — — 163 (1) of which Canadian dollar 106 (2) — — — 106 (2) Total 6,038 7 — — — 6,038 7 b) Currency and interest rate derivatives used to manage financial exposure For a description of Sanofi's objectives, policies and procedures for the management of financial foreign exchange risk and interest rate risk, refer to "–Item 11. – Quantitative and Qualitative Disclosures about Market Risk". The table below shows financial currency hedging instruments in place, with the notional amount translated into euros at the relevant closing exchange rate: 2020 2019 2018 (€ million) Notional Fair Expiry Notional Fair Expiry Notional Fair Expiry Forward currency sales 5,064 10 8,515 40 7,762 17 of which US dollar 3,721 (a) 20 2021 6,331 51 2020 5,500 38 2019 of which Japanese yen 283 — 2021 516 (5) 2020 973 (24) 2019 of which Pound sterling 257 (6) 2021 297 1 2020 184 — 2019 Forward currency purchases 9,004 (226) 10,975 78 7,291 20 of which US dollar 6,068 (b) (c) (200) 2022 7,363 42 2020 4,165 (17) 2019 of which Singapore dollar 2,250 (d) (27) 2021 2,332 32 2,022 33 2019 of which Chinese yuan renminbi 195 1 2021 270 2 2020 427 — 2019 Total 14,068 (216) 19,490 118 15,053 37 (a) Includes forward sales with a notional amount of $3,615 million expiring in 2021, designated as a hedge of Sanofi’s net investment in Bioverativ. As of December 31, 2020, the fair value of these forward contracts represented an asset of €13 million; the opposite entry was recognized in Other comprehensive income , with the impact on financial income and expense being immaterial. (b) Includes forward purchases with a notional amount of $3,000 million expiring in 2021 and 2022, designated as a fair value hedge of the exposure of $3,000 million of bond issues to fluctuations in the EUR/USD spot rate. As of December 31, 2020, the fair value of the contracts was a liability of €109 million. (c) Includes currency swaps with a notional amount of $1,000 million, receive 0.22% pay EUR -0.63% expiring in 2022, designated as a cash flow hedge of $1,000 million of bond issues. As of December 31, 2020, the fair value of the swaps was a liability of €38 million. (d) Includes forward purchases with a notional amount of SGD2,000 million expiring in 2021, designated as a fair value hedge of the exposure of an equivalent amount of intragroup loans to fluctuations in the EUR/SGD spot rate. As of December 31, 2020, the fair value of the contracts was a liability of €22 million. The table below shows interest rate hedging instruments in place as of December 31, 2020: Notional amounts by expiry date as of December 31, 2020 Of which Of which designated as (€ million) 2021 2022 2023 2024 2025 2026 Total Fair Notional Fair Notional Fair Of which Interest rate swaps pay capitalized Eonia / receive 0.06% — 2,000 — — — — 2,000 23 2,000 23 — — — pay -0.57% / receive capitalized Eonia — 600 — — — — 600 1 — — 600 1 1 receive capitalized Eonia / pay 1.48% (a) — 42 57 — — — 99 (4) 99 (4) — — — Total — 2,642 57 — — — 2,699 20 2,099 19 600 1 1 (a) These interest rate swaps hedge fixed-rate bonds with a nominal of €99 million held in a Professional Specialized Investment Fund dedicated to Sanofi and recognized within “Loans, advances and other long-term receivables” (see Note D.7.). The table below shows interest rate hedging instruments in place as of December 31, 2019: Notional amounts by expiry date as of December 31, 2019 Of which Of which designated as (€ million) 2020 2021 2022 2023 2024 2025 Total Fair Notional Fair Notional Fair Of which Interest rate swaps pay capitalized Eonia / receive 0.06% — — 2,000 — — — 2,000 28 2,000 28 — — — pay -0.57% / receive capitalized Eonia — — 600 — — — 600 3 — — 600 3 3 pay 1.81% / receive 3-month US dollar Libor 446 — — — — — 446 (2) — — 446 (2) — pay 3-month US dollar Libor / receive 2.22% 446 — — — — — 446 4 446 4 — — — receive capitalized Eonia / pay 1.48% — — 42 57 — — 99 (6) 99 (6) — — — Total 892 — 2,642 57 — — 3,591 27 2,545 26 1,046 1 3 The table below shows interest rate hedging instruments in place as of December 31, 2018: Notional amounts by expiry date as of December 31, 2018 Of which Of which designated as (€ million) 2019 2020 2021 2022 2023 2024 Total Fair Notional Fair Notional Fair Of which Interest rate swaps pay capitalized Eonia / receive 1.58% 1,550 — — — — — 1,550 30 1,550 30 — — — pay capitalized Eonia / receive 0.06% — — — 2,000 — — 2,000 15 2,000 15 — — — pay 1.81% / receive 3-month US dollar Libor — 436 — — — — 436 5 — — 436 5 7 pay 3-month US dollar Libor / receive 2.22% — 436 — — — — 436 (1) 436 (1) — — — receive capitalized Eonia / pay 1.48% — — — 42 57 — 99 (6) 99 (6) — — — Total 1,550 872 — 2,042 57 — 4,521 42 4,085 38 436 5 7 c) Equity derivatives During 2019, Sanofi contracted derivative instruments (collars) on 593,712 shares of Dexcom Inc; the collars were designated as fair value hedges of the Dexcom shares. As of December 31, 2020 they had a negative fair value of €26 million, recognized in full in Other comprehensive income . d) Actual or potential effects of netting arrangements The table below is prepared in accordance with the accounting policies described in Note B.8.3.: (€ million) 2020 2019 2018 Derivative Derivative Derivative Derivative Derivative Derivative Gross carrying amounts before offset (a) 82 (297) 225 (99) 183 (97) Gross amounts offset (in accordance with IAS 32) (b) — — — — — — Net amounts as reported in the balance sheet (a) - (b) = (c) 82 (297) 225 (99) 183 (97) Effects of other netting arrangements (not fulfilling the IAS 32 criteria for offsetting) (d) — — Financial instruments (81) 81 (89) 89 (81) 81 Fair value of financial collateral N/A N/A N/A N/A N/A N/A Net exposure (c) + (d) 1 (216) 136 (10) 102 (16)

Off balance sheet commitments

Off balance sheet commitments	12 Months Ended
	Dec. 31, 2020
Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]
Off balance sheet commitments	Off balance sheet commitments The off balance sheet commitments presented below are shown at their nominal value. D.21.1. Off balance sheet commitments relating to operating activities Off balance sheet commitments relating to Sanofi’s operating activities comprise the following: December 31, 2020 Payments due by period (€ million) Total Less than 1 to 3 to More than Leases with a term of less than 12 months, low value asset leases and lease contracts committed but not yet commenced (a)(b) 950 39 118 118 675 Irrevocable purchase commitments (c) • given (d) 7,153 4,072 1,482 572 1,027 • received (608) (236) (168) (51) (153) Research and development license agreements - commitments given • commitments related to R&D and other commitments (e) 500 261 217 10 12 • probable milestone payments (f) 2,456 163 714 972 607 Total - net commitments given (g) 10,451 4,299 2,363 1,621 2,168 (a) Includes future variable lease payments not recognized in Lease liabilities as of December 31, 2020. The principal commitment on this line is a new lease in the United States that will commence in 2021. As of December 31, 2019, the amount of such commitments was €1,067 million. (b) Lease commitments given to joint ventures were immaterial as of December 31, 2020. (c) These comprise irrevocable commitments to suppliers of (i) property, plant and equipment, net of down-payments (see Note D.3.) and (ii) goods and services. As of December 31, 2019, irrevocable commitments amounted to €6,726 million given and €(648) million received. (d) Irrevocable purchase commitments given as of December 31, 2020 include €989 million of commitments to joint ventures. (e) Commitments related to R&D, and other commitments, amounted to €784 million as of December 31, 2019. (f) This line includes only contingent milestone payments on development projects in progress. The reduction relative to December 31, 2019 (when probable milestone payments amounted to €3,040 million) is mainly due to (i) the discontinuation of the collaboration with Hanmi and (ii) the ending of a pre-existing agreement with Principia Biopharma Inc. following the acquisition of that company by Sanofi in September 2020. (g) This line excludes: (i) commitments given relating to projects in the research phase (€6.7 billion in 2020, €6.7 billion in 2019) and payments contingent upon the attainment of sales targets once a product is commercialized (€8.1 billion in 2020, €10.6 billion in 2019); (ii) commitments received in respect of the additional share of quarterly profits to which Sanofi is entitled under the collaboration agreements with Regeneron on monoclonal antibodies (capped at 10% of Regeneron’s share of quarterly profits), until Regeneron has paid 50% of the cumulative development costs incurred by the parties in the collaboration (see Note C.1.). Such commitments received were €2.6 billion in 2020 (€2.7 billion in 2019), relative to cumulative development costs of €6.6 billion as of December 31, 2020 (€3.3 billion 100% financed by Sanofi, €3.3 billion financed 80% Sanofi, 20% Regeneron); and (iii) commitments received under other agreements amounting to €3.3 billion in 2020 (€3.2 billion in 2019), including discovery, development and commercialization agreements arising from (i) the acquisition of Ablynx on May 14, 2018 (see Note D.1.), amounting to €1.1 billion as of December 31, 2020 (€1.1 billion in 2019) and (ii) the sale to Celgene of Sanofi's equity interest in Impact Biomedicines in January 2018, amounting to €0.5 billion as of December 31, 2020 (€0.5 billion in 2019). Research and development license agreements In pursuance of its strategy, Sanofi may acquire technologies and rights to products. Such acquisitions may be made in various contractual forms: acquisitions of shares, loans, license agreements, joint development, and co-marketing. These arrangements generally involve upfront payments on signature of the agreement, development milestone payments, and royalties. Some of these complex agreements include undertakings to fund research programs in future years and payments contingent upon achieving specified development milestones, the granting of approvals or licenses, or the attainment of sales targets once a product is commercialized. The “Research and development license agreements” line comprises future service commitments to fund research and development or technology, and probable contingent milestone payments regarded as reasonably achievable (i.e. all potential milestone payments relating to projects in the development phase, for which the future financial consequences are known or probable and for which there is a sufficiently reliable estimate). The major agreements entered into by Sanofi in 2020 are described below: • On June 23, 2020, it was announced that the collaboration and license agreement between Sanofi Pasteur and Translate Bio on the development of mRNA vaccines for infectious diseases would be extended to include development of a novel mRNA vaccine against the virus responsible for COVID-19. Under the terms of the extended agreement, finalized July 20, 2020, Sanofi made an upfront payment of $425 million to Translate Bio ($300 million in cash plus a private equity injection of $125 million) to acquire (i) exclusive worldwide rights to develop, manufacture and commercialize infectious disease vaccines using Translate Bio technology and (ii) an equity interest in the form of 4.9 million shares of Translate Bio common stock, valued at $95 million at the quoted market price as of that date. In addition, Translate Bio will be eligible for potential future milestone and other payments of up to $1.9 billion, including $450 million for milestones already specified in the 2018 agreement between the two companies. • In July 2020, Sanofi entered into a license agreement with Kiadis, a biopharmaceutical company developing "off-the-shelf" natural killer (NK) cell therapies for patients with life-threatening diseases. On November 2, 2020, Sanofi and Kiadis entered into a definitive agreement whereby Sanofi was to make a public offer to acquire the entire share capital of Kiadis (see Note D.21.3.). • On August 10, 2020, Sanofi signed an agreement with Kymera to develop and commercialize protein degrader therapies targeting IRAK4 in patients with immune-inflammatory diseases. Under the terms of the agreement, Sanofi has made an upfront payment of $ 150 million to Kymera, and could pay up to $2.2 billion subject to attainment of specified milestones . Other major agreements entered into by Sanofi in prior years are described below: • Roche (2019): to obtain exclusive over-the-counter (OTC) US rights to Tamiflu ® for the prevention and treatment of influenza. Under the terms of the agreement, Sanofi is responsible for leading FDA negotiations for the OTC switch; for subsequent exclusive marketing and distribution of Tamiflu ® in the US consumer health care market; and for associated scientific engagement. Tamiflu ® was previously currently sold in the US for prescription use by Genentech, a member of the Roche Group. • Regeneron (2018): (i) amendments to the 2015 Discovery and Preclinical Development Agreement and the License and Collaboration Agreement on human therapeutic antibodies; (ii) amendments to the 2015 Immuno-Oncology License and Collaboration Agreement on the development of cemiplimab (REGN2810); (iii) limited waiver and amendment of the Amended and Restated Investor Agreement pursuant to a letter agreement (the “2018 Letter Agreement”); and (iv) the 2020 Cross License and Commercialization Agreement for Praluent ® (see Note C.1.). • AnaBios Corporation (2018): partnership agreement to develop and commercialize new treatments for irregular heartbeat, primarily atrial fibrillation. • SK Chemicals (2018): partnership agreement between Sanofi Pasteur and SK Chemicals under which Sanofi acquired exclusive development and commercialization rights in the United States and Europe for vaccines derived from the cell-based technology developed by SK Chemicals. • Revolution Medicines (2018): partnership agreement in oncology to jointly develop the principal candidate derived from Revolution Medicines biological research: RMC 4630, an inhibitor of SHP2, a cellular enzyme in the protein tyrosine phosphatase family that plays an important role in multiple forms of cancer. • Translate Bio (2018): partnership agreement between Sanofi Pasteur and Translate Bio to develop messenger RNA (mRNA) vaccines derived from Translate Bio technology for five infectious disease pathogens, with an option to extend to additional pathogens. If that option is exercised, the total value of the transaction would rise to $805 million. • Sangamo Therapeutics, Inc. (2018): agreement to research, develop, and commercialize therapeutics for hemoglobinopathies, in particular beta thalassemia and sickle cell disease, based on Sangamo’s gene therapy platform; this agreement was assumed by Sanofi on the acquisition of Bioverativ on March 8, 2018 (see Note D.2.). • Denali Therapeutics Inc. (2018): collaboration agreement on the development of multiple molecules with the potential to treat a range of neurological and systemic inflammatory diseases. The two lead molecules are DNL747 in multiple sclerosis and amyotrophic lateral sclerosis, and DNL758 in systemic inflammatory diseases such as rheumatoid arthritis and psoriasis. • Immunext (2017): agreement to develop a novel antibody to treat auto-immune diseases such as multiple sclerosis and lupus. Under the agreement, Sanofi acquired an exclusive worldwide license to INX-021, a monoclonal CD40L antibody currently in preclinical development. A second parallel agreement was signed to support clinical trials. • MedImmune (a division of AstraZeneca) (2017): agreement to develop and commercialize a monoclonal antibody (MEDI8897) for the prevention of Respiratory Syncytial Virus (RSV) associated illness in newborns and infants. • ImmunoGen (2017): amendment to the license and collaboration agreement signed in 2003. ImmunoGen granted Sanofi a fully paid and exclusive license to develop, manufacture and commercialize the full series of compounds developed by Sanofi using ImmunoGen technology. • DiCE Molecules (2016): five • Innate Pharma (2016): collaboration and licensing agreement to apply Innate Pharma’s new proprietary technology to the development of innovative bispecific antibody formats engaging natural killer (NK) cells to kill tumor cells through the activating receptor NKp46. • BioNTech A.G. (2015): exclusive collaboration and license agreement to discover and develop up to five cancer immunotherapies. • Evotec AG and Apeiron Biologics AG (2015): collaboration and license agreement to discover and develop first-in-class small molecule-based immuno-oncology therapies to treat solid and hematological cancers. • Lead Pharma (2015): research collaboration and license agreement for the discovery, development and commercialization of small-molecule therapies directed against “ROR gamma t” nuclear hormone receptors to treat auto-immune diseases. • Eli Lilly and Company (2014): agreement to pursue regulatory approval for non-prescription Cialis ® (tadalafil). • Regulus Therapeutics Inc. (2010): discovery, development and commercialization of novel micro-RNA therapeutics in fibrosis. Sanofi and its alliance partners have decided to terminate the following agreements (the related commitments are no longer included in Sanofi’s off balance sheet disclosures as of December 31, 2020): • On July 23, 2020 Sanofi and Ascendis terminated their licensing and patent transfer agreement on Transcon Linker and Hydrogel Carrier technology. • On October 1, 2020, Sanofi and Evotec International GmbH terminated their research collaboration, aimed at developing beta cell-modulating diabetes treatments. Finally, Sanofi completed the acquisition of Principia Biopharma Inc. on September 28, 2020, thereby ending the license agreement signed in 2017 to develop Principia's Bruton’s tyrosine kinase (BTK) inhibitor (PRN2246) in the treatment of multiple sclerosis and (potentially) other disorders of the central nervous system. Other agreements Sanofi entered into an agreement with Royalty Pharma in December 2014 relating to development programs under which Royalty Pharma bears a portion of the remaining development costs of the project on a quarterly basis in return for royalties on future sales. This transaction is a co-investment, whereby the partner acquires an interest in the jointly-developed product by providing funding towards the development program. Consequently, the amounts received by Sanofi are recorded as a reduction in development costs, to the extent that the development costs incurred by Sanofi are recognized in profit or loss in accordance with the policies described in Note B.4.1. The products in development under the December 2014 agreement with Royalty Pharma have been launched in the United States and Europe, marking the end of the joint development programs. On February 27, 2017, Sanofi and Lonza announced a strategic partnership in the form of a joint venture to build and operate a large-scale mammalian cell culture facility for monoclonal antibody production in Visp, Switzerland. An initial investment of approximately €0.3 billion to finance construction of the facility, split 50/50 between the two partners, has now been made in full. In addition, Sanofi could pay Lonza in the region of €0.6 billion over the next fifteen years partly as its share of operating expenses and the cost of producing future batches, and partly to reserve capacity in the new facility. In February 2014, pursuant to the “Pandemic Influenza Preparedness Framework for the sharing of influenza viruses and access to vaccines and other benefits” (still effective as of December 31, 2020), Sanofi Pasteur and the World Health Organization (WHO) signed a bilateral “Standard Material Transfer Agreement” (SMTA 2). This agreement stipulates that Sanofi Pasteur will, during declared pandemic periods, (i) donate 7.5% of its real-time production of pandemic vaccines against any strain with potential to cause a pandemic, and (ii) reserve a further 7.5% of such production on affordable terms. The agreement cancels and replaces all preceding commitments to donate pandemic vaccines to the WHO. D.21.2. Off balance sheet commitments relating to financing activities Credit facilities Undrawn credit facilities are as follows: December 31, 2020 Total Expiry (€ million) Less than 1 to 3 to More than General-purpose credit facilities 8,000 4,000 — 4,000 — As of December 31, 2020, total credit facilities amounted to €8,000 million (versus €8,000 million as of December 31, 2019 and €8,000 million as of December 31, 2018). Guarantees The table below shows the amount of guarantees given and received: (€ million) 2020 2019 2018 Guarantees given: 3,291 3,103 3,010 • Guarantees provided to banks in connection with credit facilities 695 1,263 1,307 • Other guarantees given 2,596 1,840 1,703 Guarantees received (964) (703) (190) D.21.3. Off balance sheet commitments relating to Sanofi entities and business combinations On November 2, 2020, Sanofi and Kiadis entered into a definitive agreement for Sanofi to make a public offer to acquire the entire share capital of Kiadis for €5.45 per share, representing an aggregate equity value of approximately €308 million (adjusted for the value of share warrants that may be exercised in shares or settled in cash). On January 11, 2021, Sanofi and Kymab entered into an agreement under which Sanofi will acquire Kymab for an upfront payment of approximately $1.1 billion, plus up to $350 million on attainment of specified milestones (see Note G.). Off balance sheet funding commitments to associates and joint ventures are disclosed in Note D.6. The maximum amount of contingent consideration relating to business combinations is disclosed in Note D.18.

Legal and arbitral proceedings

Legal and arbitral proceedings	12 Months Ended
	Dec. 31, 2020
Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]
Legal and arbitral proceedings	Legal and arbitral proceedings Sanofi and its affiliates are involved in litigation, arbitration and other legal proceedings. These proceedings typically are related to product liability claims, intellectual property rights (particularly claims against generic companies seeking to limit the patent protection of Sanofi products), competition law and trade practices, commercial claims, employment and wrongful discharge claims, tax assessment claims, waste disposal and pollution claims, and claims under warranties or indemnification arrangements relating to business divestitures. Provisions related to legal and arbitral proceedings are recorded in accordance with the principles described in Note B.12. Most of the issues raised by these claims are highly complex and subject to substantial uncertainties; therefore, the probability of loss and an estimation of damages are difficult to ascertain. Contingent liabilities are cases for which either we are unable to make a reasonable estimate of the expected financial effect that will result from ultimate resolution of the proceeding, or a cash outflow is not probable. In either case, a brief description of the nature of the contingent liability is disclosed and, where practicable, an estimate of its financial effect, an indication of the uncertainties relating to the amount and timing of any outflow, and the possibility of any reimbursement are provided in application of paragraph 86 of IAS 37. In the cases that have been settled or adjudicated, or where quantifiable fines and penalties have been assessed, we have indicated our losses or the amount of provision accrued that is the estimate of the probable loss. In a limited number of ongoing cases, while we are able to make a reasonable estimate of the expected loss or range of the possible loss and have accrued a provision for such loss, we believe that publication of this information on a case-by-case basis or by class would seriously prejudice the Company’s position in the ongoing legal proceedings or in any related settlement discussions. Accordingly, in those cases, we have disclosed information with respect to the nature of the contingency but have not disclosed our estimate of the range of potential loss, in accordance with paragraph 92 of IAS 37. These assessments can involve a series of complex judgments about future events and can rely heavily on estimates and assumptions. Our assessments are based on estimates and assumptions that have been deemed reasonable by management. We believe that the aggregate provisions recorded for the above matters are adequate based upon currently available information. However, given the inherent uncertainties related to these cases and involved in estimating contingent liabilities, we could in the future incur judgments that could have a material adverse effect on our net income in any particular period. Long term provisions are disclosed in Note D.19. They include: • Provisions for product liability risks, litigation and other amount to €1,262 million in 2020. These provisions are mainly related to product liabilities, government investigations, competition law, regulatory claims, warranties in connection with certain contingent liabilities arising from business divestitures other than environmental matters and other claims. • Provisions for environmental risks and remediation amount to €713 million in 2020, the majority of which are related to contingencies that have arisen from business divestitures. a) Products Sanofi Pasteur Hepatitis B Vaccine Product Litigation Since 1996, more than 180 lawsuits have been filed in various French civil courts against Sanofi Pasteur and/or Sanofi Pasteur MSD S.N.C., the former French subsidiary of Sanofi, and the latter a joint venture company with Merck & Co., Inc. now terminated, for which past ongoing litigation is now managed by the originating party. In such lawsuits, the plaintiffs allege that they suffer from a variety of neurological disorders and autoimmune diseases, including multiple sclerosis and Guillain-Barré syndrome as a result of receiving the hepatitis B vaccine. In January 2008, both the legal entity Sanofi Pasteur MSD S.N.C., and a corporate officer of this company, as well as a former corporate officer of Sanofi Pasteur, were placed under investigation in an ongoing criminal inquiry in France relating to alleged side effects caused by the hepatitis B vaccine. In March 2012, Sanofi Pasteur and its former pharmacist in charge (i.e. the deputy Chief Executive Officer) were placed under an “advised witness” (" témoin assisté" ) status. In March 2016, the investigating judges decided to dismiss the proceedings. Several civil parties appealed against this decision. In June 2018, the Prosecutor General requested confirmation of the dismissal. In June 2019, the Investigation Chamber of the Paris Court of Appeals confirmed the decision taken by the investigating judges in March 2016 to dismiss the proceedings. Several plaintiffs have decided to appeal such decision before the French Supreme Court ( Cour de cassation ). In October 2017, the French Supreme Court ( Cour de cassation ) dismissed two appeals filed by the plaintiffs against two decisions of the Appeal Court of Paris ( Cour d’appel ). In January 2018, the Appeal Court of Bordeaux found a causal link between hepatitis B vaccine and multiple sclerosis. Sanofi Pasteur Europe appealed this decision before the French Supreme Court ( Cour de cassation ). In July 2019, the French Supreme Court ( Cour de cassation ) cancelled the judgment of the Appeal Court of Bordeaux and referred the case back to the Appeal Court of Toulouse. The hearing is planned for December 6, 2021. Taxotere ® Product Litigation in the US As of December 31, 2020, there were approximately 10,137 plaintiffs in courts across the country, with approximately 871 of those plaintiffs being spouses who have filed loss of consortium claims. Suits have been filed against affiliates of Sanofi under US state law for personal injuries allegedly sustained in connection with the use of Taxotere ® . The actions are held in several jurisdictions, including the federal and/or state courts of Louisiana, New Jersey, California, and Delaware. A first bellwether trial took place in September 2019 and issued a verdict in Sanofi's favor. The next bellwether trial is currently scheduled to begin in May 2021. It is not possible, at this stage, to reliably assess the outcome of these lawsuits or the potential financial impact on the Company. Taxotere ® - Mississippi Attorney General Litigation in the US In October 2018, the Attorney General for the State of Mississippi filed a civil action in Hinds County, Mississippi, Chancery Court against various Sanofi Defendants related to Taxotere ® . The State asserts one cause of action based on the Mississippi Consumer Protection Act (“MCPA”) and seeks a permanent injunction prohibiting Defendants’ conduct and civil penalties of up to $10,000 for each violation. In December 2018, Sanofi removed the matter to the US District Court for the Southern District of Mississippi. It is not possible, at this stage, to assess reliably the outcome of this lawsuit or the potential financial impact on the Company. Zantac ® Litigation in the US In September 2019, the US Food and Drug Administration (“FDA”) announced it was investigating the claims of an online pharmacy’s Citizen Petition that the medication Zantac® (the brand name for ranitidine) used for stomach heartburn contains or can generate the chemical N-Nitrosodimethylamine (“NDMA”), an alleged human carcinogen. As a precautionary measure, Sanofi initiated a voluntary recall of branded over-the-counter Zantac® in October 2019. Concurrent with FDA’s investigation, multiple personal injury lawsuits and class actions alleging that Zantac® causes various cancers and seeking damages for either alleged personal injuries or alleged economic injuries were filed. Most of those cases have been coordinated into an MDL in the Southern District of Florida. That Court entered a case management schedule that provides for 18 months of discovery leading up to motions on general causation and briefing on class certification. Other cases are pending in various state courts. In addition, in November 2019, Sanofi received a Civil Investigative Demand (“CID”) related to this issue from the Arizona Attorney General. In June 2020, the New Mexico Attorney General filed a complaint against Sanofi, the previous marketing authorization holders for branded Zantac®, a dozen generic manufacturers, and several retailers. The complaint brings claims for alleged violations of the New Mexico Unfair Practices Act, violations of the New Mexico False Advertising Act, violations of the New Mexico Public Nuisance Statute, common law public nuisance, and negligence. In June 2020, Sanofi received a notice from the US Department of Justice Civil Division and US Attorney’s Office for the Eastern District of Pennsylvania of an investigation into allegations that pharmaceutical manufacturers violated the False Claims Act, 31 U.S.C. § 3729, in relation to the drug Zantac® and ranitidine hydrochloride through alleged failure to disclose to the federal government information about the potential presence of NDMA. The notice requests information and documents from Sanofi including applications and communications with FDA. In November 2020, the Mayor and City Council of Baltimore filed a complaint against Sanofi, the previous marketing authorization holders for branded Zantac®, generic manufacturers, and several retailers. The complaint alleges violations of the Maryland Consumer Protection statute, public nuisance, and negligence. In January 2021, Sanofi was served with the Center for Environmental Health’s Second Amended Complaint alleging Proposition 65 violations. The case, which also names generic manufacturers and retailers, is pending in California Superior Court in Alameda County. As of December 31, 2020, there were a total of 977 filed personal injury cases (representing 1,607 ingesting plaintiffs) and 25 putative class actions. Additional cases may be filed. It is not possible, at this stage, to assess reliably the outcome of these lawsuits or the potential financial impact on Sanofi. Zantac ® Litigation in Canada In October 2019, an application to authorize the bringing of a class action on behalf of all Canadian residents was filed in Quebec Superior Court relating to ranitidine and naming Sanofi Consumer Health Inc. as a defendant. Representative Plaintiffs claim that they suffered personal injury, including cancer, from the ingestion of ranitidine and are seeking general and punitive damages in an unspecified amount. In October 2019, and April 2020, two proposed class action proceedings were filed in Ontario Superior Court relating to ranitidine and naming Sanofi Consumer Health Inc., Sanofi-Aventis Canada Inc., Chattem (Canada) Inc. and Sanofi Pasteur Limited as Defendants. Representative Plaintiffs claim that they suffered personal injury, including cancer, from the ingestion of ranitidine and are seeking general, special, statutory, punitive and aggravated damages in an unspecified amount. Additionally, they seek restitution for unjust enrichment in an amount equivalent to the purchase price of Zantac®. In December 2019, a proposed class action proceeding was filed in Alberta Court of Queen’s Bench relating to ranitidine and naming Sanofi Consumer Health Inc. as a defendant. The representative plaintiff is claiming on behalf of all Canadian residents damages, including personal injury, arising allegedly from the ingestion of ranitidine. General, special and punitive damages are being claimed in an unspecified amount. In February 2020, an amended class action proceeding now naming Sanofi Consumer Health Inc. as a Defendant along with 21 other Defendants was filed in the British Columbia Supreme Court. The representative plaintiff is claiming on behalf of all Canadian residents damages, including personal injury, arising allegedly from the ingestion of ranitidine. General, special and punitive damages are being claimed in an unspecified amount. As a result, as of December 31, 2020, 5 class actions have been filed in the above-mentioned provinces; but additional cases may be filed. It is not possible, at this stage, to assess reliably the outcome of these lawsuits or the potential financial impact on Sanofi. Depakine ® Product Litigation in France Civil proceedings As of December 31, 2020, 75 families brought a civil claim involving 126 people exposed in utero to sodium valproate against a French affiliate of Sanofi seeking indemnification under French law for personal injuries allegedly suffered by children in connection with the use of sodium valproate by their mothers during pregnancy to treat their epilepsy (Depakine ® ). These actions are held in several jurisdictions in France. Twenty-three lawsuits are proceedings on the merits, the most advanced has been tried at the French Supreme Court level which issued in November 2019 a ruling quashing partially the November 2017 Orléans Appeal Court decision against Sanofi ordering payment of approximately €2 million to the plaintiff and €1 million to the CPAM ( Caisse Primaire d’Assurance Maladie ). The Supreme Court sent the case back before another Appeal Court to rule on Sanofi’s argument on the exoneration cause relating “to compliance of the product with mandatory regulations”, as well as on the question of defectiveness of the product and the evaluation of the injuries. There is currently no date set for the hearing of this case. In a class action lawsuit filed in May 2017 by the APESAC ( Association des Parents d’Enfants souffrant du Syndrome de l’Anti-Convulsivant ) before the Paris Civil Court, the judge denied claimant’s motion on interim measures in November 2017. APESAC lodged an appeal which was rejected by the Court of Appeal of Paris in October 2018. No date for trial hearing has been set yet. In July 2020, a collective redress against the French affiliate was filed by 63 families, seeking indemnification for a prejudice of anxiety . Criminal investigation A criminal investigation has been ongoing since May 2015 before the Paris Civil Court. In January 2020, the French affiliate of Sanofi was indicted for aggravated deception and involuntary injuries and in July 2020 for involuntary manslaughter. In July 2020, a judicial supervision of the affiliate was ordered, together with the implementation of financial guarantees. Sanofi has filed several motions including a motion for nullity of its indictment. In November 2020, the Health Authority ( ANSM) was indicted for involuntary injuries and involuntary manslaughters. Public compensation scheme: The French government has, through the 2017 Finance Law adopted on December 29, 2016, set up a public compensation scheme which is meant to indemnify patients for damages suffered in connection with the prescription of sodium valproate and its derivatives. The scheme entered into force in July 2017 and was further amended through the 2020 Finance Law, with notably the introduction of presumptions of default for lack of information of the mother since 1982 for malformations and since 1984 for neurodevelopment disorders. The scheme was amended again through the 2021 Finance Law in order to increase the maximum premium applicable in case of refusal to make an offer (or insufficient offer) which would be deemed unjustified by a court ruling. The committee of the compensation scheme has issued final opinions holding the French affiliate liable for damages either in full or in part along with the French State. The French affiliate disagreed with the committee’s conclusions and has accordingly not offered indemnification to the claimants who have received compensation from the ONIAM ( Office National d'Indemnisation des Accidents Médicaux ). The ONIAM is now seeking reimbursement from Sanofi who has filed legal actions to oppose ONIAM’s payment orders. It is not possible, at this stage, to assess reliably the outcome of these cases or the potential financial impact on the Company. Dengvaxia ® (Philippines) Since early 2018 up to present date, several claims were filed in the Philippines by parents of deceased children whose deaths were allegedly due to vaccination with Dengvaxia ® . Early March 2019 and 2020, the Philippine Department of Justice (DOJ) prosecution panel announced it had found probable cause to indict six Sanofi employees / former employees and former Government officials for “reckless imprudence” resulting in homicides. Several criminal actions have been filed in court as a result of the DOJ finding probable cause for the cases to proceed. A Motion for Reconsideration (MR) was filed by Sanofi Pasteur Inc. (Philippines) and was dismissed in November 2019 for all respondents who filed the MR except for one. The remaining respondents have filed a further Petition for Review to the DOJ Secretary in December 2019 and the said petition remains pending. b) Patents Ramipril Canada Patent Litigation Sanofi was involved in a number of legal proceedings involving companies which market generic Altace ® (ramipril) in Canada. In 2004, Sanofi unsuccessfully brought Notice of Compliance proceedings (NOC proceedings) at the end of which eight manufacturers obtained marketing authorizations from the Canadian Minister of Health for generic versions of ramipril in Canada. Sanofi filed unsuccessful patent infringement actions against all those companies and ultimately Sanofi was liable for damages under Section 8. Sanofi made payment in complete satisfaction of those awards. In June 2011, while the Section 8 damages action was proceeding in Federal Court, Apotex commenced an action in the Ontario Superior Court of Justice asserting damages under the Ontario Statute of Monopolies, the UK Statute of Monopolies, and the Trade-marks Act (the “Ontario Action”). The Ontario Action was stayed pending exhaustion of appeals in the Section 8 damages action and, despite having received full compensation in the Section 8 action, was reinitiated by Apotex after the conclusion of the appeals. In June 2017, the Canadian Supreme Court determined that the legal principles applied in the ramipril invalidity decision were unsound and in 2018, Sanofi amended its pleadings to address this development. In January 2019, the motions judge denied Sanofi’s motion to seek summary judgment on the issue of applicability of the Statute of Monopolies in view of the allowed pleadings amendment. In view of the pleadings amendment and denial of summary judgment, the trial for this matter, originally expected for fall 2019, will now likely be delayed significantly. Praluent ® (alirocumab)-related Amgen Patent Litigation in the US In 2014, Amgen filed four separate complaints against Sanofi and Regeneron in the US District Court for the District of Delaware (“District Court”) asserting patent infringement relating to Sanofi and Regeneron’s Praluent ® product. Together these complaints allege that Praluent ® infringes seven patents for antibodies targeting PCSK9 and seek injunctive relief and unspecified damages. In January 2016, Sanofi and Regeneron informed the District Court that they stipulated to infringement. In March 2016, the District Court granted Judgment as a Matter of Law (JMOL) of obviousness in favor of Amgen and JMOL on an aspect of willful infringement in favor of Sanofi and Regeneron. In addition, in 2016, a jury verdict upheld the validity of Amgen’s asserted claims of two patents. In January 2017, the District Court denied Sanofi’s and Regeneron’s motion for a new trial and their motion for JMOL and granted an injunction preventing the marketing, selling or manufacturing of Praluent ® in the US during the term of the two Amgen patents starting from February 21, 2017. In early February 2017, the US Court of Appeals for the Federal Circuit (“Federal Circuit”) stayed (suspended) the permanent injunction for Praluent ® during Sanofi’s and Regeneron’s appeal of the validity judgment and injunction ruling in the Federal Circuit. In October 2017, the Federal Circuit granted a new trial on certain validity issues (lack of written description and enablement), vacated (lifted) the District Court’s judgment and found that the District Court improperly granted a permanent injunction. In February 2019, a jury from the US District Court for the District of Delaware upheld the validity of three of the five asserted claims of two Amgen patents. The jury agreed with Sanofi and Regeneron for two of the five asserted claims, finding they were invalid. On February 8, 2019, the District Court dismissed Amgen’s claim for willful infringement. In August 2019, the Court ruled in favor of Sanofi and Regeneron and found as a matter of law that Amgen’s remaining three asserted patent claims are invalid. This means that Sanofi and Regeneron have successfully invalidated all five asserted patent claims in the District Court. Amgen appealed to the Federal Circuit. Praluent ® (alirocumab)-related Amgen Patent Litigation in Europe Amgen has filed six separate patent infringement lawsuits against Sanofi and Regeneron in Europe based on Amgen’s European patent EP2215124. In July 2016, Amgen filed a lawsuit in the UK High Court of Justice, Chancery Division Patents Court against five Sanofi entities and Regeneron alleging that alirocumab infringes its ‘124 (UK) patent, seeking injunctive relief and unspecified damages; Sanofi has counterclaimed invalidity. In February 2017, the UK action had been stayed (suspended) on terms agreed by the parties. In October 2020, the court issued a judgment in favor of Sanofi and Regeneron to lift the stay of the litigation and awarded Sanofi 50,000 pounds of legal cost. Based on the invalidation of the broad PCSK-9 claims in the European Patent Office (EPO), Amgen has agreed to withdraw its claim of infringement against Sanofi for the sale of Praluent ® in the U.K. In July 2016, Amgen filed a lawsuit in Germany in the Regional Court, Düsseldorf against three Sanofi entities and Regeneron alleging that alirocumab infringes its ‘124 (DE) patent, seeking injunctive relief and unspecified damages. In July 2019, the Regional Court of Düsseldorf ruled, finding infringement, and issued an injunction which requires Sanofi and Regeneron to stop marketing, selling, and manufacturing Praluent ® in Germany. Sanofi and Regeneron appealed. Amgen enforced the injunction and Sanofi and Regeneron complied. Praluent ® was no longer commercialized in Germany. The Higher Regional Court of Düsseldorf held a hearing in November 2020 and based on the invalidation of Amgen’s broad PCSK-9 claims in the EPO, reversed the lower court’s infringement judgement against Sanofi and Regeneron, and also reversed the injunction of the manufacture and sales of Praluent ® in Germany. Similarly based on the invalidation of the broad PCSK-9 claims in the EPO, Amgen also has withdrawn or agreed to withdraw its claim of infringement against Sanofi for the sale of Praluent ® in France, Italy, the Netherlands and Spain. Praluent ® (alirocumab)-related EPO Patent Oppositions In February 2016, the European Patent Office (EPO) granted Amgen’s European Patent EP2215124. In February 2016, Sanofi filed an opposition with the EPO requesting the revocation of Amgen’s ’124 patent in its entirety for all contracting states on the grounds that the subject-matter of the opposed patent is not patentable. In November 2016, Sanofi filed a second opposition (in the name of three Sanofi affiliates named as defendants in the German infringement action - see above), and Regeneron filed a separate opposition, requesting revocation of Amgen’s ’124 patent. In November 2018, the EPO Opposition Division maintained Amgen’s patent claims in amended form. Subsequently, Sanofi and Regeneron each filed a notice of appeal. In October 2020, the EPO’s Technical Board of Appeals ruled in favor of Sanofi and Regeneron and invalidated all of Amgen’s broad claims covering PCSK-9 antibodies, leaving them claims that are narrow and do not cover Praluent ® . Praluent ® (alirocumab)-related Amgen Opposition and Patent Litigation in Japan In May 2017, Amgen filed a lawsuit in the Tokyo District Court (TDC), against Sanofi K.K. for patent infringement of two of its Japanese Patents, JP5705288 and JP5906333. Amgen sought injunctive relief to prevent the infringing manufacture, use and sale of alirocumab, as well as destruction of Praluent ® and alirocumab, and the cost of litigation. Sanofi had counterclaimed invalidity and non-infringement. The validity of these two Japanese patents was separately challenged by Sanofi in the Japanese Patent Office (JPO) by filing invalidation actions in 2016. In August 2017, the JPO upheld the patents’ claims in amended form. In December 2017, Sanofi filed an appeal to the Intellectual Property High Court (IPHC) demanding revocation of the JPO decision. In December 2018, the IPHC rendered its decision that Amgen’s patents are valid, upholding the JPO’s earlier decision. Sanofi filed an appeal to the Supreme Court in February 2019. In January 2019, the TDC ruled in Amgen’s favor, finding its patents valid and infringed. The TDC did not order provisional enforcement of an injunction. Sanofi appealed to the IPHC. In October 2019, the IPHC affirmed the TDC's decision that Amgen’s patents are valid and infringed. Sanofi filed an appeal to the Supreme Court in November 2019. In April 2020, the Supreme Court denied Sanofi’s appeal in the invalidation action and the infringement proceeding. The injunction issued by the Tokyo District Court became enforceable and Sanofi complied. Praluent ® is no longer commercialized in Japan. Dupixent ® (dupilumab)-related Amgen Patent Opposition and Revocation in Europe Immunex Corporation, an Amgen affiliate, is the registered proprietor of European Patent EP2292665. The claims of this patent relate to, among other things, human monoclonal antibodies that are capable of inhibiting IL-4 induced biological activity and which compete with one of four reference antibodies for binding to a cell that expresses human IL-4R. In April 2016, Sanofi and Regeneron each filed an opposition in the European Patent Office (EPO) against EP2292665, seeking its revocation on the basis that, inter alia, the claims are invalid for prohibited “added matter”, lack of novelty, lack of inventive step and lack of sufficient disclosure. In September 2016, Sanofi also filed a civil action in the UK High Court (Chancery Division/Patents Court) seeking revocation of the UK designation of EP2292665 on similar grounds. In January 2017, at the joint request of Sanofi and Immunex, the UK High Court ordered that the revocation action be stayed pending the final determination of the pending EPO opposition proceedings. The EPO rendered its decision in November 2017 and revoked the patent in its entirety. The decision revoking the patent was issued in January 2018. In early 2018, Immunex appealed the decision of the EPO. In September 2017, Sanofi and Regeneron filed oppositions in the EPO against Amgen’s European Patent EP2990420, which is a divisional of the EP2292665 Patent discussed above. The issues in this opposition were similar to those made in the oppositions against EP2292665. In February 2019, the EPO revoked the patent EP2990420 in its entirety, finding the claims invalid for lack of sufficiency. Immunex filed a notice of appeal in May 2019. A hearing date for the appeal has not been scheduled yet. Dupixent ® (dupilumab)-related Amgen Inter Partes Reviews and Patent Litigation in the US In March and July 2017, Sanofi and Regeneron filed collectively three petitions for Inter Partes Review (IPR) for US Patent No. 8,679,487 with the United States Patent and Trademark Office (USPTO). In these petitions, Sanofi and Regeneron collectively attack the validity of all the claims of this patent. The USPTO declined to institute an IPR on the first petition but granted Sanofi and Regeneron’s second and third petitions and instituted Inter Partes Reviews of all challenged claims in the ‘487 Patent. In April 2017, Immunex filed a complaint in the US District Court for the Central District of California against Sanofi and Regeneron asserting that the commercialization of Dupixent ® infringes US Patent No. 8,679,487. In response, among other things, Sanofi and Regeneron asserted affirmative defenses of non-infringement, invalidity, and unenforceability. In February 2019, the USPTO issued final written decisions on the two IPR petitions and declined to hold the challenged claims of the US patent No. 8,679,487 invalid for anticipation but found all claims on the ‘487 patent invalid for obviousness. In April 2019, Immunex appealed the USPTO’s decision invalidating all 17 claims of US Patent No. 8,679,487 to the Federal Circuit. Also in April 2019, Sanofi and Regeneron appealed the USPTO’s decision that the challenged claims of the ‘487 Patent are not invalid as anticipated by Immunex’s ‘132 Publication. With respect to the Immunex complaint, on February 28, 2019, the US District Court granted parties’ joint stipulation seeking to stay (put on-hold) the district court litigation. Accordingly, the litigation is stayed pending final resolution of any rehearings or appeals of the related IPR proceedings. In October 2020, the Court of Appeals for the Federal Circuit (CAFC) affirmed the USPTO’s decision that all claims of US Patent No. 8,679,487 (which Immunex asserted against Dupixent®) are invalid. Immunex has indicated that it plans to appeal the decision to the US Supreme Court. Jevtana ® (cabazitaxel)-related patent litigation in the US Jevtana ® is covered by five Orange Book listed patents U.S. 5,847,170, U.S. 7,241,907, U.S. 8,927,592, U.S. 10,583,110 and U.S. 10,716,777. In May to July 2020, Sanofi filed patent infringement suits under Hatch-Waxman against 12 generic filers asserting the ‘110 patent and the ‘777 patent in the U.S. District Court for the District of Delaware. Sanofi has reached settlement agreements with some of the defendants and the suit against the remaining defendants are ongoing. In January 2021, the District Court issued a claim construction decision in favor of the defendants. A trial has been scheduled to start in May 2021. Mylan filed a petition for Inter Partes Review of the ‘592 patent at the United States Patent and Trademark Office (USPTO). In September 2017, the USPTO issued a Final Written Decision that invalidated all the challenged claims of the ‘592 patent and denied Sanofi’s contingent motion to amend. Sanofi appealed the USPTO’s decision and in February 2019, the Federal Circuit vacated the USPTO’s decision and remanded it back for reconsideration. In October 2019, the USPTO granted Sanofi’s motion to amend and Mylan appealed. In January 2021, the Federal Circuit affirmed the USPTO’s decision. Plavix ® Litigation (Commonwealth) in Australia In August 2007, GenRX (a subsidiary of Apotex) obtained registration of a generic clopidogrel bisulfate product on the Australian Register of Therapeutic Goods. At the same time, GenRX filed a patent invalidation action with the Federal Court of Australia, seeking revocation of Sanofi’s Australian enantiomer patent claiming clopidogrel salts (a “nullity action”). In September 2007, Sanofi obtained a preliminary injunction from the Federal Court preventing commercial launch of this generic clopidogrel bisulfate product until judgment on the substantive issues of patent validity and infringement. In February 2008, Spirit Pharmaceuticals Pty. Ltd. also filed a nullity action against Sanofi’s Australian enantiomer patent. The Spirit proceeding was consolidated with the Apotex proceeding. In August 2008, the Australian Federal Court confirmed that the claim in Sanofi’s Australian enantiomer patent directed to clopidogrel bisulfate (the salt form in Plavix ® ) was valid and the patent infringed. On appeal, the Full Federal Court of Australia held in September 2009 that all claims in the patent are invalid. Sanofi’s appeal to the Australia High Court was denied in March 2010. The security bond posted by Sanofi in connection with the preliminary injunction obtained in 2007 was subsequently increased from AUD40 million to AUD204 million. Apotex sought damages in the range of AUD20 million to AUD236 million, plus interest for having been subject to an injunction. In April 2013, the Australian Department of Health and Ageing filed an application before the Federal Court of Australia seeking payment of damages from Sanofi related

Provisions for discounts, rebat

Provisions for discounts, rebates and sales returns	12 Months Ended
	Dec. 31, 2020
Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]
Provisions for discounts, rebates and sales returns	Provisions for discounts, rebates and sales returnsAdjustments between gross sales and net sales, as described in Note B.13., are recognized either as provisions or as reductions in accounts receivable, depending on their nature. The table below shows movements in these items: (€ million) Government and State programs (a) Managed care and GPO programs (b) Chargeback Rebates Sales Other Total Balance at January 1, 2018 2,086 663 377 1,067 547 6 4,746 Changes in scope of consolidation 37 2 — (123) — 2 (82) Provision related to current period sales 4,624 2,038 3,620 5,942 465 56 16,745 Net change in provision related to prior period sales (2) (4) (1) (11) (35) 3 (50) Payments made (4,673) (2,055) (3,714) (5,732) (448) (54) (16,676) Currency translation differences 76 30 12 (3) 17 — 132 Balance at December 31, 2018 (c) 2,148 674 294 1,140 546 13 4,815 Provision related to current period sales 5,542 2,563 4,649 5,888 554 96 19,292 Net change in provision related to prior period sales (27) — (1) (6) (27) 14 (47) Payments made (5,529) (2,528) (4,637) (5,719) (465) (72) (18,950) Currency translation differences 44 17 7 27 13 — 108 Balance at December 31, 2019 (c) 2,178 726 312 1,330 621 51 5,218 Provision related to current period sales 5,970 2,752 4,633 6,221 628 110 20,314 Net change in provision related to prior period sales (54) — — (113) (34) — (201) Payments made (5,552) (2,556) (4,604) (5,838) (512) (112) (19,174) Currency translation differences (35) (14) (8) (43) (15) (3) (118) Balance at December 31, 2020 (c) 2,507 908 333 1,557 688 46 6,039 (a) Primarily US government programs: Medicaid (€1,015 million in 2020, €1,017 million in 2019, €1,033 million in 2018) and Medicare (€726 million in 2020, €810 million in 2019 and €829 million in 2018). (b) Mainly rebates and other price reductions granted to healthcare authorities in the United States (including Managed Care: €692 million in 2020, €649 million in 2019 and €604 million in 2018). (c) Provisions related to US net sales amounted to €3,982 million as of December 31, 2020, €3,585 million as of December 31, 2019 and €3,509 million as of December 31, 2018.

Personnel costs

Personnel costs	12 Months Ended
	Dec. 31, 2020
Employee Benefits [Abstract]
Personnel costs	Personnel costs Total personnel costs (other than termination benefits, presented in Note D.27.) include the following items: (€ million) 2020 2019 2018 Salaries 6,508 6,590 6,547 Social security charges (including defined-contribution pension plans) 1,874 1,949 1,954 Stock options and other share-based payment expense 274 252 282 Defined-benefit plans 159 119 261 Other employee benefits 261 229 225 Total 9,076 9,139 9,269 The total number of registered employees was 99,412 as of December 31, 2020, compared with 100,409 as of December 31, 2019 and 104,226 as of December 31, 2018.

Other operating income

Other operating income	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Other operating income	Other operating income Other operating income totaled €696 million in 2020, versus €825 million in 2019 and €484 million in 2018. Other operating income includes (i) gains from disposals relating to ongoing operations, including in particular disposals of intangible rights, amounting to €307 million in 2020 (versus €296 million in 2019 and €326 million in 2018); and (ii) income from Sanofi’s pharmaceutical partners, amounting to €199 million in 2020 (including €164 million from Regeneron, see Note D.26. below), compared with €103 million in 2019 and €32 million in 2018. This line item also includes (i) for 2019, the favorable impact of top-up pension plan amendments following the application of the Pacte law in France; and (ii) for 2018, a €112 million gain related to a data transfer agreement.

Other operating expenses

Other operating expenses	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Other operating expenses	Other operating expenses Other operating expenses totaled €1,415 million in 2020, compared with €1,207 million in 2019 and €548 million in 2018. For 2020, this line item includes €1,090 million of expenses relating to the alliance with Regeneron (see Note C.1.), versus €715 million for 2019 and €225 million in 2018 (as shown in the table below): (€ million) 2020 2019 2018 Income & expense related to profit/loss sharing under the Monoclonal Antibody Alliance (727) (253) 177 Additional share of profit paid by Regeneron towards development costs 75 21 — Reimbursement to Regeneron of selling expenses incurred (349) (449) (388) Total - Monoclonal Antibody Alliance (1,001) (681) (211) Immuno-Oncology Alliance 89 62 4 Other (mainly Zaltrap ® ) (14) (14) (14) Other operating income/(expenses), net related to the Regeneron Alliance (926) (633) (221) of which amount presented in Other operating income (Note D.25.) 164 82 4 Other operating expenses included acquisition-related costs of €29 million in 2020, and of €56 million in 2018. Charges to provisions for litigation and environmental risks are also recorded within this line item. Finally, Other operating expenses also includes shares of profits due to alliance partners (other than BMS and the alliance partner under the Actonel ® agreement) under product marketing agreements (€16 million in 2020, versus €28 million in 2019 and €50 million in 2018).

Restructuring costs and similar

Restructuring costs and similar items	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Restructuring costs and similar items	Restructuring costs and similar items Restructuring costs and similar items amounted to €1,064 million in 2020, €1,062 million in 2019 and €1,480 million in 2018, and comprise the following items: (€ million) 2020 2019 2018 Employee-related expenses 690 791 517 Charges, gains or losses on assets (a) 149 106 162 Compensation for early termination of contracts (other than contracts of employment) 40 49 352 Decontamination costs (2) 27 5 Other restructuring costs 187 89 444 Total 1,064 1,062 1,480 (a) This line consists of accelerated depreciation charges related to site closures (including leased sites), and gains or losses on divestments of assets arising from reorganization decisions made by Sanofi. In 2020, employee-related expenses amounted to €690 million, and consisted of termination benefits further to the announcement of plans to adapt Sanofi’s organization (primarily in Europe) in line with the new “Play to Win” strategy announced in December 2019. In 2019, restructuring costs mainly comprised termination benefits of €791 million (primarily in Europe, the United States and Asia), plus asset write-downs and accelerated depreciation charges of €106 million. Costs relating to Sanofi transformation programs included within the “Other restructuring costs” line, as defined in Note B.19., amounted to €173 million in 2020 compared with €109 million in 2019 and €145 million in 2018. In 2018, restructuring costs mainly comprised (i) termination benefits of €517 million, including provisions associated with headcount adjustments in Europe announced in December 2018; (ii) a provision of €283 million booked as of December 31, 2018 for penalties arising from the restructuring of the Immuno-Oncology Discovery and Development agreement with Regeneron to end the collaboration on research programs included in the initial July 2015 agreement (see Note C.1.); (iii) the costs of transferring the infectious diseases early stage R&D pipeline and research unit, amounting to €252 million and mainly comprising payments to Evotec over a five-year period, including an upfront payment of €60 million in 2018: and (iv) €162 million of losses on property, plant and equipment due to site closures or divestments under transformation or reorganization programs.

Other gains and losses, and lit

Other gains and losses, and litigation	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Other gains and losses, and litigation	Other gains and losses, and litigation Other gains and losses, and litigation for 2020 comprise a net gain of €136 million, mainly relating to the sale of Seprafilm ® . For 2019, this line item comprises a net gain of €327 million, mainly relating to a gain on settlement of litigation. For 2018, this line item consists of the €502 million pre-tax gain arising on the divestment of the European Generics business (completed September 30, 2018), net of separation costs (see Note D.2.).

Financial expenses and income

Financial expenses and income	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Financial expenses and income	Financial expenses and income An analysis of Financial expenses and Financial income is set forth below: (€ million) 2020 2019 2018 Cost of debt (a) (328) (318) (396) Interest income (b) 103 146 123 Cost of net debt (225) (172) (273) Non-operating foreign exchange gains/(losses) (6) 1 6 Unwinding of discounting of provisions (c) (11) (25) (24) Net interest cost related to employee benefits (59) (87) (75) Gains/(losses) on disposals of financial assets 6 — 63 Net interest expense on lease liabilities (d) (38) (39) — Other (4) 19 32 Net financial income/(expenses) (337) (303) (271) comprising: Financial expenses (390) (444) (435) Financial income 53 141 164 (a) Includes net gains on interest rate and currency derivatives used to manage debt: €93 million in 2020, €187 million in 2019 and €75 million in 2018. (b) Includes net gains on interest rate and currency derivatives used to manage cash and cash equivalents: €66 million in 2020, €55 million in 2019 and €51 million in 2018. (c) Primarily on provisions for environmental risks, restructuring provisions, and provisions for product-related risks (see Note D.19.). (d) Impact of the application of IFRS 16. In 2020, 2019 and 2018, the impact of the ineffective portion of hedging relationships was not material.

Income tax expense

Income tax expense	12 Months Ended
	Dec. 31, 2020
Income Taxes [Abstract]
Income tax expense	Income tax expense Sanofi has elected for tax consolidations in a number of countries, principally France, Germany, the United Kingdom and the United States. The table below shows the allocation of income tax expense between current and deferred taxes: (€ million) 2020 2019 2018 Current taxes (1,912) (1,892) (1,212) Deferred taxes 99 1,753 731 Total (1,813) (139) (481) Income before tax and investments accounted for using the equity method 13,804 2,822 4,405 The difference between the effective tax rate and the standard corporate income tax rate applicable in France is explained as follows: (as a percentage) 2020 2019 2018 Standard tax rate applicable in France 32.0 34.4 34.4 Difference between the standard French tax rate and the rates applicable to Sanofi (a) (18.2) (22.9) (17.4) Revisions to tax exposures and settlements of tax disputes 0.5 4.8 (1.4) Impact of US tax reform (b) — — (4.3) Impact of past acquisitions and divestitures — (6.2) — Fair value remeasurement of contingent consideration (c) — (2.6) 0.2 Other items (d) (1.2) (2.6) (0.6) Effective tax rate 13.1 4.9 10.9 (a) The difference between the French tax rate and tax rates applicable to foreign subsidiaries reflects the fact that Sanofi has operations in many countries, most of which have lower tax rates than France. For 2020, this line includes the difference between the standard French tax rate and the tax rate applicable to the gain on divestment of Regeneron shares. (b) For 2018, this line reflects an adjustment of €188 million to the estimated tax charge on deemed repatriation attributable to the accumulated earnings of non-US operations. (c) For 2019, this line includes impacts related to the MSD contingent consideration and to the CVRs issued in connection with the acquisition of Genzyme. (d) In determining the amount of the deferred tax liability for 2020, 2019 and 2018, Sanofi took into account changes in the ownership structure of certain subsidiaries. For 2018, "Other items" also includes the net tax effect of taxable temporary differences associated with holdings in Sanofi subsidiaries. For the periods presented, the amount of deferred tax assets recognized in profit or loss that were initially subject to impairment losses at the time of a business combination is immaterial.

Share of profit_loss from inves

Share of profit/loss from investments accounted for using the equity method	12 Months Ended
	Dec. 31, 2020
Interests In Other Entities [Abstract]
Share of profit loss from investments accounted for using the equity method	Share of profit/loss from investments accounted for using the equity method The line item Share of profit/(loss) from investments accounted for using the equity method comprises: (€ million) 2020 2019 2018 Regeneron (a) 343 245 484 BMS co-promotion entities (b) 1 5 12 Other investments accounted for using the equity method 15 5 3 Total 359 255 499 (a) Following the transaction of May 29, 2020 as described in Note D.1., which resulted in the divestment of 22.8 million Regeneron shares, Sanofi no longer exercises significant influence over Regeneron. The 2020 figure presented represents Sanofi’s equity-accounted share of Regeneron’s net profits up to and including that date. (b) On February 28, 2020, Sanofi acquired from Bristol-Myers Squibb the remaining 50.1% equity interest not yet held by Sanofi in the three partnerships that organize the commercialization of Plavix ® in the United States and Puerto Rico, for a total consideration of $12 million. This acquisition was accounted for in accordance with IFRS 3 (Business Combinations).

Net income attributable to non-

Net income attributable to non-controlling interests	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Net income attributable to non-controlling interests	Net income attributable to non-controlling interests The table below shows Net income attributable to non-controlling interests for the reporting periods presented: (€ million) 2020 2019 2018 Share of co-promotion profits attributable to BMS (a) — — 83 Share of net income attributable to other non-controlling interests 36 31 21 Total 36 31 104 (a) For 2018: share of co-promotion profits attributable to BMS for territories covered by entities majority owned by Sanofi; there was no tax effect on these amounts because BMS received its share before tax. The payment to buy out the BMS non-controlling interests was made on December 31, 2018 (see Note C.2.).

Related party transactions

Related party transactions	12 Months Ended
	Dec. 31, 2020
Related Party [Abstract]
Related party transactions	Related party transactions The principal related parties are companies over which Sanofi has control or significant influence, joint ventures, key management personnel, and principal shareholders. Sanofi has not entered into any material transactions with any key management personnel. Financial relations with Sanofi’s principal shareholders fall within the ordinary course of business and were immaterial in the years ended December 31, 2020, 2019 and 2018. Note F.1. lists the principal companies controlled by Sanofi; those companies are fully consolidated, as described in Note B.1. Transactions between those companies, and between the parent company and its subsidiaries, are eliminated when preparing the consolidated financial statements. Transactions with companies over which Sanofi has significant influence, and with joint ventures, are presented in Note D.6. Key management personnel include corporate officers and the members of the Executive Committee (an a verage of 11 members in 2020, 15 members in 2019 and 15 members in 2018). The table below shows, by type, the compensation paid to key management personnel: (€ million) 2020 2019 2018 Short-term benefits (a) 36 31 38 Post-employment benefits (b) 3 (8) 9 Share-based payment 18 30 33 Total recognized in profit or loss 57 53 80 (a) Compensation, employer’s social security contributions, directors’ attendance fees, and any termination benefits (net of reversals of termination benefit obligations). (b) This line item includes in 2019 the favorable impact of top-up pension plan amendments following the application of the Pacte law in France. The table below shows (i) the aggregate top-up pension obligation in favor of certain corporate officers who hold or have held executive positions within Sanofi and of Executive Committee members, and (ii) the aggregate amount of termination benefits and lump-sum retirement benefits payable to key management personnel. (€ million) 2020 2019 2018 Aggregate top-up pension obligation 28 48 59 Aggregate termination benefits and lump-sum retirement benefits 6 5 10

Disclosures about major custome

Disclosures about major customers and credit risk	12 Months Ended
	Dec. 31, 2020
Financial Instruments [Abstract]
Disclosures about major customers and credit risk	Disclosures about major customers and credit risk Credit risk is the risk that customers (wholesalers, distributors, pharmacies, hospitals, clinics or government agencies) may fail to pay their debts; for Sanofi, that risk is mainly concentrated on amounts receivable from wholesalers in the United States. Sanofi manages credit risk by vetting customers in order to set credit limits and risk levels, and asking for guarantees or insurance where necessary; performing controls; and monitoring qualitative and quantitative indicators of accounts receivable balances, such as the period of credit taken and overdue payments. Sales generated by Sanofi with its biggest customers, in particular certain wholesalers in the United States, represented 21% of net sales in 2020. The three largest customers respectively accounted for approximately 10%, 6% and 5% of Sanofi's net sales in 2020 (8%, 5% and 3% in 2019; 9%, 6% and 4% in 2018).

Segment information

Segment information	12 Months Ended
	Dec. 31, 2020
Operating Segments [Abstract]
Segment information	Segment information As indicated in Note B.26., Sanofi has three operating segments: Pharmaceuticals, Consumer Healthcare and Vaccines. The Pharmaceuticals segment comprises, for all geographical territories, the commercial operations of the following global franchises: Specialty Care (Dupixent ® , Multiple Sclerosis, Neurology, Other Inflammatory Diseases & Immunology, Rare Diseases, Oncology, and Rare Blood Disorders) and General Medicines (Diabetes, Cardiovascular and Established Prescription Products), together with research, development and production activities dedicated to the Pharmaceuticals segment. This segment also includes associates whose activities are related to pharmaceuticals. Following the transaction of May 29, 2020, Regeneron is no longer an associate of Sanofi (see Note D.1.). Consequently, the Pharmaceuticals segment no longer includes Sanofi’s equity-accounted share of Regeneron’s profits for all the periods presented in this note. The Consumer Healthcare segment comprises, for all geographical territories, the commercial operations for Sanofi's Consumer Healthcare products, together with research, development and production activities dedicated to those products. The Vaccines segment comprises, for all geographical territories, the commercial operations of Sanofi Pasteur, together with research, development and production activities dedicated to vaccines. Inter-segment transactions are not material. The costs of global support functions (External Affairs, Finance, Human Resources, Legal Affairs, Information Solutions & Technologies, Sanofi Business Services, etc.) are managed centrally at group-wide level. The costs of those functions are presented within the “Other” category. That category also includes other reconciling items such as retained commitments in respect of divested activities. In 2020, Sanofi adapted its management reporting to reflect its new organizational structure. This resulted in cost reallocations between the Pharmaceuticals, Consumer Healthcare and Vaccines segments and the “Other” category, and product reallocations between Pharmaceuticals and Consumer Healthcare. Expenses relating to Global Medical Affairs, allocated to the “Other” category in the old management reporting structure, were reallocated to the Pharmaceuticals segment. Only figures presented for 2019 have been restated, to reflect the new management reporting structure as well as reallocations of some countries between geograophical regions. Due to lack of available data and the over-complex adjustments that would be required (in particular to Sanofi's reporting tools), 2018 figures have not been restated to reflect the changes arising from the new segment reporting model. D.35.1. Segment results D.35.1.1. Analysis of net sales The table below sets forth Sanofi’s net sales for the years ended December 31, 2020, 2019 and 2018: (€ million) Europe United States Other 2020 Europe United Other 2019 (a) Europe United Other 2018 Pharmaceuticals 6,819 9,635 9,220 25,674 6,797 8,918 9,985 25,700 7,303 7,897 9,485 24,685 General Medicines 4,505 2,869 7,346 14,720 4,809 3,386 8,342 16,537 5,299 3,510 7,607 16,416 of which Lantus ® 537 929 1,195 2,661 599 1,149 1,264 3,012 684 1,614 1,267 3,565 Toujeo ® 374 267 292 933 343 289 251 883 290 344 206 840 Praluent ® 121 106 34 261 112 112 34 258 86 154 21 261 Multaq ® 24 274 14 312 41 295 11 347 43 296 11 350 Lovenox ® 656 30 665 1,351 730 33 596 1,359 870 38 557 1,465 Plavix ® 129 10 777 916 142 — 1,192 1,334 147 — 1,293 1,440 Generics 100 161 671 932 139 152 783 1,074 568 124 798 1,490 Specialty Care 2,314 6,766 1,874 10,954 1,988 5,532 1,643 9,163 2,004 4,387 1,878 8,269 of which Aubagio ® 473 1,448 124 2,045 414 1,351 114 1,879 385 1,157 105 1,647 Cerezyme ® 249 177 264 690 259 184 265 708 270 174 267 711 Myozyme ® / Lumizyme ® 389 359 200 948 388 331 199 918 374 284 182 840 Fabrazyme ® 200 406 211 817 185 410 218 813 175 383 197 755 Eloctate ® — 445 193 638 — 517 167 684 — 500 108 608 Jevtana ® 187 246 103 536 170 212 102 484 158 179 85 422 Dupixent ® 386 2,808 340 3,534 204 1,669 201 2,074 75 660 53 788 Consumer Healthcare 1,359 1,071 1,964 4,394 1,434 1,105 2,156 4,695 1,403 1,066 2,191 4,660 of which Allergy, Cough & Cold 305 361 430 1,096 364 323 502 1,189 347 303 474 1,124 Pain 539 181 505 1,225 543 185 552 1,280 521 165 568 1,254 Digestive 319 86 453 858 326 157 502 985 314 195 477 986 Nutritionals 127 43 441 611 130 38 453 621 125 37 513 675 Vaccines 973 2,759 2,241 5,973 851 2,733 2,147 5,731 728 2,577 1,813 5,118 of which Polio/Pertussis/ 331 412 1,363 2,106 315 380 1,251 1,946 296 397 1,056 1,749 Influenza Vaccines 441 1,575 456 2,472 230 1,289 372 1,891 177 1,233 298 1,708 Total net sales 9,151 13,465 13,425 36,041 9,082 12,756 14,288 36,126 9,434 11,540 13,489 34,463 (a) The analysis of net sales for 2019 has been restated to align on Sanofi's new management reporting structure, and to reflect the reallocation of certain countries between geographical regions. D.35.1.2. Business operating income Sanofi reports segment results on the basis of “Business operating income”. This indicator is used internally by Sanofi’s chief operating decision maker to measure the performance of each operating segment and to allocate resources. Following the transaction of May 29, 2020, Regeneron is no longer an associate of Sanofi (see Note D.1.). Consequently, the definition of the “Business operating income” indicator has been adjusted, and no longer includes Sanofi’s share of the net income of Regeneron. This means that the Share of profit/(loss) from investments accounted for using the equity method line in the table reconciling Operating income (as shown in the income statement) to “Business operating income” no longer includes the equity-accounted share of profits from Regeneron. The comparatives presented for 2019 and 2018 have been restated to reflect that adjustment. In addition, the gain arising on the divestment of the equity investment in Regeneron is not included in “Business operating income”, with the exception of the gain on the remeasurement of the 400,000 retained shares at market value at the transaction date. In addition, with effect from January 1, 2020 “Business operating income” includes depreciation charged against right-of-use assets recognized under IFRS 16 (Leases), applicable since January 1, 2019, and excludes rental expenses previously recognized under IAS 17. In the interests of consistency, the "Business operating income" figures presented for 2019 have been restated to include the effects of (i) IFRS 16, and (ii) certain expenses and income presented differently for segment reporting purposes to align on Sanofi’s new 2020 management reporting structure (see Note D.35., "Segment information", above). "Business operating income" is derived from Operating income , adjusted as follows: • the amounts reported in the line items Restructuring costs and similar items , Fair value remeasurement of contingent consideration and Other gains and losses, and litigation are eliminated; • amortization and impairment losses charged against intangible assets (other than software and other rights of an industrial or operational nature) are eliminated; • the share of profits/losses from investments accounted for using the equity method is added; • net income attributable to non-controlling interests is deducted; • other acquisition-related effects (primarily the workdown of acquired inventories remeasured at fair value at the acquisition date, and the impact of acquisitions on investments accounted for using the equity method) are eliminated; • restructuring costs relating to investments accounted for using the equity method are eliminated; and • the gain on the divestment of Regeneron shares on May 29, 2020 is eliminated (this elimination does not include the gain on the remeasurement of the 400,000 retained shares at market value as of that date). The table below sets forth Sanofi’s segment results for the years ended December 31, 2020, December 31, 2019 and December 31, 2018: 2020 (a) (€ million) Pharmaceuticals Consumer Vaccines Other Total Net sales 25,674 4,394 5,973 — 36,041 Other revenues 128 59 1,141 — 1,328 Cost of sales (7,025) (1,506) (3,328) (245) (12,104) Research and development expenses (4,331) (136) (692) (370) (5,529) Selling and general expenses (5,097) (1,450) (822) (2,021) (9,390) Other operating income and expenses (488) 54 2 (130) (562) Share of profit/(loss) from investments accounted for using the equity method 5 9 2 — 16 Net income attributable to non-controlling interests (33) (5) — — (38) Business operating income 8,833 1,419 2,276 (2,766) 9,762 (a) " Business operating income" no longer includes Sanofi’s equity-accounted share of Regeneron’s net profits (see definition above, and Note D.1.). 2019 (a) (€ million) Pharmaceuticals Consumer Vaccines Other Total Net sales 25,700 4,695 5,731 — 36,126 Other revenues 173 57 1,275 — 1,505 Cost of sales (6,750) (1,599) (3,372) (252) (11,973) Research and development expenses (4,850) (149) (639) (380) (6,018) Selling and general expenses (5,442) (1,529) (823) (2,089) (9,883) Other operating income and expenses (625) 193 — 50 (382) Share of profit/(loss) from investments accounted for using the equity method 5 (5) 9 — 9 Net income attributable to non-controlling interests (29) (6) — — (35) Business operating income 8,182 1,657 2,181 (2,671) 9,349 (a) In line with the amended management reporting structure adopted in 2020, " Business operating income" no longer includes Sanofi’s equity-accounted share of Regeneron’s net profits (see definition above, and Note D.1.). It includes the effects of IFRS 16, and the reallocation of some products from Phamaceuticals to Consumer Healthcare (immaterial impact) and the reallocation of costs previously reported in "Other" to operating segments, for a net amount of €291 million). 2018 (a) (€ million) Pharmaceuticals Consumer Vaccines Other Total Net sales 24,685 4,660 5,118 — 34,463 Other revenues 252 — 962 — 1,214 Cost of sales (6,738) (1,539) (2,854) (190) (11,321) Research and development expenses (4,572) (143) (555) (624) (5,894) Selling and general expenses (5,431) (1,534) (710) (2,156) (9,831) Other operating income and expenses (37) 101 (4) (124) (64) Share of profit/(loss) from investments accounted for using the equity method 17 1 (3) — 15 Net income attributable to non-controlling interests (96) (10) — — (106) Business operating income (a) 8,080 1,536 1,954 (3,094) 8,476 (a) " Business operating income" no longer includes Sanofi’s equity-accounted share of Regeneron’s net profits (see definition above, and Note D.1.). Due to lack of available data and the over-complex adjustments that would be required (in particular to Sanofi's reporting tools), 2018 figures have not been restated to reflect the changes arising from the new organizational structure. The table below, presented in compliance with IFRS 8, shows a reconciliation between aggregated “Business operating income” for the segments and Income before tax and investments accounted for using the equity method: (€ million) 2020 2019 2018 Business operating income (a) 9,762 9,349 8,476 Share of profit/(loss) from investments accounted for using the equity method (b) (16) (9) (15) Net income attributable to non-controlling interests (c) 38 35 106 Amortization and impairment of intangible assets (2,011) (5,750) (2,888) Fair value remeasurement of contingent consideration 124 238 117 Expenses arising from the impact of acquisitions on inventories (d) (53) (3) (114) Restructuring costs and similar items (1,064) (1,062) (1,480) Other expenses related to business combinations — — (28) Other gains and losses, and litigation (e) 136 327 502 Gain on divestment of Regeneron shares on May 29, 2020 (f) 7,225 — — Operating income 14,141 3,125 4,676 Financial expenses (390) (444) (435) Financial income 53 141 164 Income before tax and investments accounted for using the equity method 13,804 2,822 4,405 (a) "Business operating income" as presented for 2019 and 2018 has been restated to exclude Sanofi’s equity-accounted share of Regeneron’s net profits, which amounted to € 411 million in 20 19 and €408 million in 2018 (see above). In addition, "Business operating income" for 2019 has been restated to include (i) the effects of IFRS 16 and (ii) the effect of certain expenses and income being presented differently for segment reporting purposes to align on Sanofi’s new 2020 management reporting structure. (b) Excludes restructuring costs relating to investments accounted for using the equity method and expenses arising from the impact of acquisitions on investments accounted for using the equity method. For 2019 and 2018, this line has been restated to exclude any effect of equity method accounting for the investment in Regeneron following the divestment of Sanofi's entire equity interest (with the exception of the 400,000 shares retained by Sanofi) on May 29, 2020. (c) Excludes (i) restructuring costs and (ii) other adjustments attributable to non-controlling interests. (d) This line records the impact of the workdown of acquired inventories remeasured at fair value at the acquisition date. (e) For 2020, this line mainly comprises the gain on the sale of operations related to the Seprafilm ® activity to Baxter. For 2019, this line comprises a net gain, mainly arising from a settlement of litigation. For 2018, this line includes the gain on the divestment of Sanofi's European Generics business (€510 million). (f) This line includes the gain on the sale of (i) 13 million shares of Regeneron common stock in the registered public offering and (ii) the 9.8 million shares repurchased by Regeneron, but does not include the gain arising from the remeasurement of the 400,000 retained shares at market value as of May 29, 2020. D.35.2. Other segment information The tables below show the split by operating segment of (i) the carrying amount of investments accounted for using the equity method, (ii) acquisitions of property, plant and equipment, and (iii) acquisitions of intangible assets. The principal investments accounted for using the equity method in the Pharmaceuticals segment are entities majority owned by BMS (up to and including February 29, 2020, see Note C.2.), and Infraserv GmbH & Co. Höchst KG. Acquisitions of intangible assets and property, plant and equipment correspond to acquisitions paid for during the period. 2020 (€ million) Pharmaceuticals Consumer Vaccines Total Investments accounted for using the equity method 154 — 47 201 Acquisitions of property, plant and equipment 755 95 404 1,254 Acquisitions of other intangible assets 532 6 322 860 2019 (€ million) Pharmaceuticals Consumer Vaccines Total Investments accounted for using the equity method (a) 205 4 40 249 Acquisitions of property, plant and equipment (b) 773 88 462 1,323 Acquisitions of other intangible assets 321 51 121 493 (a) This line has been restated to eliminate Sanofi’s equity investment in Regeneron, which had a carrying amount of €3,342 million as of December 31, 2019 (see Note D.35., "Segment Information", above) . (b) Includes the effect of restatements needed to align on Sanofi’s new 2020 management reporting structure. (€ million) 2018 Pharmaceuticals Consumer Vaccines Total Investments accounted for using the equity method (a) 297 20 30 347 Acquisitions of property, plant and equipment (b) 1,046 5 364 1,415 Acquisitions of other intangible assets 434 7 121 562 (a) This line has been restated to eliminate Sanofi’s equity investment in Regeneron, which had a carrying amount of €3,055 million as of December 31, 2018 (see Note D.35., "Segment Information", above) . (b) Due to lack of available data and the over-complex adjustments that would be required (in particular to Sanofi's reporting tools), 2018 figures have not been restated to reflect the changes arising from the new segment reporting model. D.35.3. Information by geographical region The geographical information on net sales provided below is based on the geographical location of the customer. In accordance with IFRS 8, the non-current assets reported below exclude right-of-use assets relating to leases as determined under IFRS 16, investments accounted for using the equity method, other non-current assets, non-current income tax assets, and deferred tax assets. 2020 (€ million) Total Europe of which North of which Other Net sales 36,041 9,151 2,223 14,060 13,465 12,830 Non-current assets: • property, plant and equipment owned 9,365 5,895 3,189 2,542 1,899 928 • goodwill 44,364 — — — — — ▪ other intangible assets 18,421 6,278 — 10,675 — 1,468 2019 (a) (€ million) Total Europe of which North of which Other Net sales (a) 36,126 9,082 2,261 13,370 12,756 13,674 Non-current assets: • property, plant and equipment owned 9,717 5,827 3,141 2,862 2,264 1,028 • goodwill 44,519 — — — — — • other intangible assets 16,572 6,941 — 7,825 — 1,806 (a) Net sales and property, plant and equipment owned for 2019 have been restated to align on the new management reporting structure, and to reflect the reallocation of certain countries between geographical regions. (€ million) 2018 (a) Total Europe of which North of which Other Net sales 34,463 9,434 2,319 12,193 11,540 12,836 Non-current assets: • property, plant and equipment owned 9,651 5,871 3,163 2,719 2,238 1,061 • goodwill 44,235 — — — — — • other intangible assets 21,889 8,058 — 11,190 — 2,641 (a) Due to lack of available data and the over-complex adjustments that would be required (in particular to Sanofi's reporting tools), 2018 figures have not been restated to reflect the changes arising from the new segment reporting model. As stated in Note D.5., goodwill is not allocated by geographical region.

Principal accountants' fees and

Principal accountants' fees and services	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Principal accountants' fees and services	Principal accountants’ fees and services PricewaterhouseCoopers Audit and Ernst & Young et Autres served as independent auditors of Sanofi for the year ended December 31, 2020 and for all other reporting periods presented. The table below shows fees charged by those firms and member firms of their networks to Sanofi and consolidated subsidiaries in the years ended December 31, 2020 and 2019. Ernst & Young PricewaterhouseCoopers 2020 2019 2020 2019 (€ million) Amount % Amount % Amount % Amount % Audit: Statutory audit of separate and consolidated financial statements (a) 13.9 82 % 14.0 90 % 15.1 98 % 14.6 99 % Services other than statutory audit (b) 3.1 18 % 1.6 10 % 0.3 2 % 0.2 1 % Audit-related services (c) 2.5 0.9 0.2 0.2 Tax — — — — Other 0.6 0.7 0.1 — Total 17.0 100 % 15.6 100 % 15.4 100 % 14.8 100 % (a) Includes services provided by the independent auditors of the parent company and French subsidiaries: Ernst & Young €7.4 million in 2020, €7.2 million in 2019; PricewaterhouseCoopers €8.2 million in 2020, €7.3 million in 2019. (b) Services other than statutory audit provided by Ernst & Young et Autres during 2020 comprised: - work on share capital transactions and securities issues submitted to the Annual General Meeting (in extraordinary business) for approval; - additional procedures to enable reports previously signed by the firm to be incorporated by reference; - agreed-upon and audit procedures in connection with a proposed divestment; and - issuance of the Independent third party’s report on the consolidated statement of extra-financial performance. Services other than statutory audit provided by PricewaterhouseCoopers Audit during 2020 comprised: - work on share capital transactions and securities issues submitted to the Annual General Meeting (in extraordinary business) for approval; - additional procedures to enable reports previously signed by the firm to be incorporated by reference; - contractual audits, assurance engagements, agreed-upon procedures and thematic studies. (c) Includes services provided by the independent auditors of the parent company and French subsidiaries: Ernst & Young: €2.4 million in 2020, €0.8 million in 2019; PricewaterhouseCoopers €0.2 million in 2020, €0.1 million in 2019. Audit Committee pre-approval and procedures The Audit Committee of Sanofi has adopted a policy and established certain procedures for the approval of audit services and for the pre-approval of other services to be provided by the independent auditors. In 2020, the Audit Committee established a limit for permitted audit-related and other services (i.e. services other than statutory audit) that can be provided by the independent auditors, and the related fees.

List of principal companies inc

List of principal companies included in the consolidation scope during 2020	12 Months Ended
	Dec. 31, 2020
Interests In Other Entities [Abstract]
List of principal companies included in the consolidation scope during 2020	List of principal companies included in the scope of consolidation during 2020 F.1. Principal fully consolidated companies The table below shows the principal subsidiaries and their country of incorporation: Europe Financial interest (%) as of December 31, 2020 Hoechst GmbH Germany 100.0 Sanofi-Aventis Deutschland GmbH Germany 100.0 A. Nattermann & Cie. GmbH Germany 100.0 Sanofi-Aventis GmbH Austria 100.0 Sanofi Belgium Belgium 100.0 Ablynx N.V. Belgium 100.0 Genzyme Flanders BVBA Belgium 100.0 Sanofi A/S Denmark 100.0 Sanofi-Aventis S.A. Spain 100.0 Sanofi Oy Finland 100.0 Sanofi France 100.0 Sanofi-Aventis France France 100.0 Sanofi Winthrop Industrie France 100.0 Sanofi-Aventis Recherche & Développement France 100.0 Sanofi-Aventis Groupe France 100.0 Sanofi Chimie France 100.0 Francopia France 100.0 Sanofi-Aventis Participations France 100.0 Genzyme Polyclonals SAS France 100.0 Sanofi Pasteur France 100.0 Aventis Pharma S.A. France 100.0 Sanofi Biotechnology France 100.0 Sanofi Mature IP France 100.0 Sanofi Pasteur NVL France 100.0 Sanofi Vaccine Technologies France 100.0 Sanofi Pasteur Europe France 100.0 Sanofi-Aventis A.E.B.E. Greece 100.0 Sanofi-Aventis Private Co, Ltd Hungary 99.6 Chinoin Private Co. Ltd Hungary 99.6 Carraig Insurance DAC Ireland 100.0 Sanofi-Aventis Ireland Ltd Ireland 100.0 Genzyme Ireland Limited Ireland 100.0 Sanofi Finance Ireland limited Ireland 100.0 Sanofi S.R.L. Italy 100.0 Genzyme Global Sarl Luxembourg 100.0 Sanofi-Aventis Norge AS Norway 100.0 Sanofi-Aventis Netherlands B.V. Netherlands 100.0 Genzyme Europe B.V. Netherlands 100.0 Sanofi Foreign Participations B.V. Netherlands 100.0 Sanofi-Aventis Sp. z.o.o. Poland 100.0 Sanofi Produtos Farmaceuticos Lda Portugal 100.0 Sanofi-Aventis, s.r.o. Czech Republic 100.0 Sanofi Romania SRL Romania 100.0 Sanofi-Aventis UK Holdings Limited United Kingdom 100.0 Genzyme Limited United Kingdom 100.0 Aventis Pharma Limited United Kingdom 100.0 AO Sanofi Russia Russia 100.0 sanofi-aventis Slovakia s.r.o. Slovakia 100.0 Sanofi AB Sweden 100.0 Sanofi-Aventis (Suisse) SA Switzerland 100.0 Sanofi Ilac Sanayi ve Ticaret A.S. Turkey 100.0 Sanofi Pasteur Asi Ticaret A.S. Turkey 100.0 Europe Financial interest (%) as of December 31, 2020 Sanofi Saglik Urunleri Limited Sirketi Turkey 100.0 Limited Liability Company Sanofi-Aventis Ukraine Ukraine 100.0 United States Financial interest (%) as of December 31, 2020 Genzyme Therapeutic Products Limited Partnership United States 100.0 Aventis Inc. United States 100.0 Sanofi US Corporation United States 100.0 Synthorx, Inc. United States 100.0 Sanofi US Services Inc. United States 100.0 Sanofi-Aventis U.S. LLC United States 100.0 Chattem, Inc. United States 100.0 Aventisub LLC United States 100.0 Genzyme Corporation United States 100.0 Sanofi Pasteur Inc. United States 100.0 VaxServe, Inc. United States 100.0 Bioverativ Inc. United States 100.0 Bioverativ U.S.LLC United States 100.0 Bioverativ Therapeutics Inc. United States 100.0 Sanofi Pharmaceuticals Holding Partnership United States 100.0 Principia Biopharma Inc. United States 100.0 Other Countries Financial interest (%) as of December 31, 2020 Sanofi-Aventis South Africa (Pty) Ltd South Africa 100.0 Sanofi-Aventis Algérie Algeria 100.0 Sanofi Arabia Trading Company Limited Saudi Arabia 75.0 Sanofi-Aventis Argentina S.A. Argentina 100.0 Genzyme de Argentina S.A. Argentina 100.0 Sanofi-Aventis Healthcare Pty Ltd Australia 100.0 Sanofi-Aventis Australia Pty Ltd Australia 100.0 Sanofi Medley Farmaceutica Ltda Brazil 100.0 Sanofi-Aventis Canada Inc. Canada 100.0 Sanofi Pasteur Limited Canada 100.0 Sanofi (Hangzhou) Pharmaceuticals Co., Ltd China 100.0 Sanofi (China) Investment Co., Ltd China 100.0 Sanofi (Beijing) Pharmaceuticals Co.Ltd China 100.0 Sanofi Pasteur Biologies Co., Ltd China 100.0 Shenzhen Sanofi pasteur Biological Products Co, Ltd China 100.0 Genfar S.A. Colombia 100.0 Sanofi-Aventis de Colombia S.A. Colombia 100.0 Sanofi-Aventis Korea Co. Ltd South Korea 100.0 Sanofi Pasteur Ltd South Korea 100.0 Sanofi-Aventis Gulf FZE United Arab Emirates 100.0 Sanofi-Aventis del Ecuador S.A. Ecuador 100.0 Sanofi Egypt Egypt 99.8 Sanofi-Aventis Hong-Kong Limited Hong Kong 100.0 Sanofi-Synthelabo (India) Private Ltd India 100.0 Sanofi India Limited India 60.4 Sanofi Healthcare India Private Limited India 99.9 PT Aventis Pharma Indonesia 80.0 Sanofi-Aventis Israël Ltd Israel 100.0 Sanofi K.K. Japan 100.0 SSP Co.,Ltd Japan 100.0 Sanofi Nichi-Iko K.K. Japan 51.0 Sanofi-Aventis (Malaysia) SDN. BHD. Malaysia 100.0 Sanofi-Aventis Maroc Morocco 100.0 Sanofi-Aventis de Mexico S.A. de C.V. Mexico 100.0 Sanofi-Aventis Winthrop S.A. de C.V. Mexico 100.0 Sanofi Pasteur S.A. de C.V. Mexico 100.0 Sanofi-Aventis Pakistan Limited Pakistan 52.9 Sanofi-Aventis de Panama S.A. Panama 100.0 Sanofi-Aventis del Peru S.A. Peru 100.0 sanofi-aventis Puerto Rico Inc Puerto Rico 100.0 Sanofi-Aventis Philippines Inc. Philippines 100.0 Sanofi-Aventis Singapore Pte. Ltd Singapore 100.0 Aventis Pharma (Manufacturing) Pte. Ltd Singapore 100.0 Sanofi Taiwan Co., Ltd Taiwan 100.0 Sanofi-Aventis (Thailand) Ltd Thailand 100.0 Sanofi-Aventis de Venezuela S.A. Venezuela 100.0 Sanofi-aventis Vietnam Company Limited Vietnam 100.0 Shanghai Rongheng Pharmaceutical Co, Ltd China 100.0 Sanofi Vietnam Shareholding Company Limited Vietnam 85.0 Azteca Vacunas, S.A. de C.V. Mexico 100.0 F.2. Principal investments accounted for using the equity method Financial interest (%) as of December 31, 2020 GlaxoSmithKline Consumer Healthcare, L.P. United States 11.7 Infraserv GmbH & Co. Höchst KG Germany 31.2 Maphar Morocco 48.3 MCM Vaccine B.V. Netherlands 50.0 MSP Vaccine Company (formerly MCM company) United States 50.0

Events subsequent to December 3

Events subsequent to December 31, 2020	12 Months Ended
	Dec. 31, 2020
Disclosure of non-adjusting events after reporting period [abstract]
Events subsequent to December 31, 2020	Events subsequent to December 31, 2020 On January 11, 2021, Sanofi entered into an agreement with Kymab, a UK-based clinical-stage biopharmaceutical company developing fully human monoclonal antibodies with a focus on immune-mediated diseases and immuno-oncology therapeutics, under which Sanofi will acquire Kymab for an upfront payment of approximately $ 1.1 billion plus up to $ 350 million upon achievement of certain development milestones. Apart from that event, no other significant events occurred between the end of the reporting period and the date on which the consolidated financial statements were signed off by the Board of Directors.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2020
Corporate Information And Statement Of IFRS Compliance [Abstract]
International financial reporting standards (IFRS)	International financial reporting standards (IFRS) The consolidated financial statements cover the twelve-month periods ended December 31, 2020, 2019 and 2018. In accordance with Regulation No. 1606/2002 of the European Parliament and Council of July 19, 2002 on the application of international accounting standards, Sanofi has presented its consolidated financial statements in accordance with IFRS since January 1, 2005. The term “IFRS” refers collectively to international accounting and financial reporting standards (IASs and IFRSs) and to interpretations of the interpretations committees (SIC and IFRIC) with mandatory application as of December 31, 2020. The consolidated financial statements of Sanofi as of December 31, 2020 have been prepared in compliance with IFRS as issued by the International Accounting Standards Board (IASB) and with IFRS as endorsed by the European Union as of December 31, 2020. Sanofi has also early adopted, with effect from January 1, 2020, the second amendment to IFRS 9 on interest rate benchmark reform, which was endorsed by the European Union between the end of the reporting period and the date on which the financial statements were closed off (see Note A.2.2.). IFRS as endorsed by the European Union as of December 31, 2020 are available under the heading “IFRS Financial Statements” via the following web link: https://www.efrag.org/Endorsement.
New standards, amendments and interpretations	New standards, amendments and interpretations A.2.1. New standards applicable from January 1, 2020 During 2018, the IASB published a number of amendments mandatorily applicable at the earliest from January 1, 2020 onwards. These include “Definition of a Business” (amendment to IFRS 3), issued October 22, 2018, which applies prospectively to business combinations from January 1, 2020 onwards. Those amendments do not have a material impact on the consolidated financial statements for the year ended December 31, 2020. On May 28, 2020, the IASB issued “Covid-19-Related Rent Concessions”, an amendment to IFRS 16. The amendment, which came into force on October 12, 2020, allows lessees not to account for rent concessions as lease modifications if they are a direct consequence of Covid-19 and meet certain conditions. The impact of first-time application of this amendment was immaterial. In its consolidated financial statements for the year ended December 31, 2019, and with no material impact, Sanofi (i) early adopted the Phase 1 amendment to IFRS 9 relating to interest rate benchmark reform and (ii) in light of the IFRIC agenda decision of November 2019, reviewed the lease term of contracts cancellable without the payment of a penalty, either by the lessor or the lessee, in order to take into account the concept of "economic penalty".
New pronouncements issued by IASB and applicable from 2021 or later	New pronouncements issued by the IASB and applicable from 2021 or later This note describes standards, amendments and interpretations issued by the IASB that will have mandatory application in 2021 or subsequent years, and Sanofi’s position regarding future application. On January 23, 2020, the IASB issued “Classification of Liabilities as Current or Non-current”, an amendment to IAS 1. On May 14, 2020, the IASB issued “Reference to the Conceptual Framework”, an amendment to IFRS 3; “Proceeds before Intended Use”, an amendment to IAS 16; “Onerous Contracts – Cost of Fulfilling a Contract”, an amendment to IAS 37; and “Annual Improvements to IFRS standards 2018-2020”. Sanofi does not expect a material impact from those amendments, which are applicable at the earliest from January 1, 2022 (subject to endorsement by the European Union). Sanofi will not early adopt those amendments. On August 27, 2020, the IASB issued a second amendment (Phase 2) to IFRS 9, relating to interest rate benchmark reform. Sanofi has early adopted that amendment in the consolidated financial statements for the year ended December 31, 2020. The hedging instruments contracted by Sanofi affected by interest rate benchmark reform are the interest rate swaps described in note D.20b.), maturing from 2022. Fair value hedging relationships consist of swapping fixed-rate euro-denominated bonds to the overnight benchmark rate applicable in euros (Eonia), with a perfect alignment of critical terms between hedged items and hedging instruments. Consequently, those hedging relationships currently have no ineffective portion, and that will remain the case once Eonia is replaced by Ester, the new euro overnight benchmark rate. Cash flow hedging relationships consist of swapping floating-rate synthetic debt (combination of fixed-rate bonds and fixed-to-Eonia interest rate swaps) to fixed rates, with the same perfect alignment of critical terms between hedged items and hedging instruments. Sanofi expects that Eonia will be replaced by Ester simultaneously in the interest rate swap contracts affected, and hence believes that the cash flow hedging relationships in question will remain fully effective. Consequently, Sanofi does not expect the interest rate benchmark reform to have a material impact on its hedging relationships.
Use of estimates and judgments	Use of estimates and judgments The preparation of financial statements requires management to make reasonable estimates and assumptions based on information available at the date of the finalization of the financial statements. Those estimates and assumptions may affect the reported amounts of assets, liabilities, revenues and expenses in the financial statements, and disclosures of contingent assets and contingent liabilities as of the date of the review of the financial statements. Examples of estimates and assumptions include: • amounts deducted from sales for projected sales returns, chargeback incentives, rebates and price reductions (see Notes B.13 and D.23.); • impairment of property, plant and equipment, intangible assets, and investments accounted for using the equity method (see Notes B.6. and D.5.); • the valuation of goodwill and the valuation and estimated useful life of acquired intangible assets (see Notes B.3.2., B.4., D.4. and D.5.); • the measurement of equity investments in unquoted entities (see Notes B.8.5. and D.12.); • the measurement of contingent consideration receivable in connection with asset divestments (see Notes B.8.5. and D.12.) and of contingent consideration payable (see Notes B.3. and D.18.); • the measurement of financial assets at amortized cost (see Note B.8.5.); • the amount of post-employment benefit obligations (see Notes B.23. and D.19.1.); • the amount of liabilities or provisions for restructuring, litigation, tax risks and environmental risks (see Notes B.12., B.19., B.20., D.19. and D.22.); and • the amount of deferred tax assets resulting from tax losses available for carry-forward and deductible temporary differences (see Notes B.22. and D.14.). Actual results could differ from these estimates.
Hyperinflation	Hyperinflation Under IAS 29, (Financial Reporting in Hyperinflationary Economies), non-monetary balance sheet items must be restated using a general price index; monetary items are not restated. Items in the income statement and the statement of comprehensive income must be restated by applying the change in the general price index from the dates when the income and expense items were initially recorded in the financial statements. In Lebanon, the cumulative inflation rate over the last three years is in excess of 100%, based on a combination of indices used to measure inflation in that country. On November 10, 2020, the IPTF (International Practices Task Force) recommended that Lebanon be treated as a hyperinflationary economy. Consequently, Sanofi decided to apply IAS 29 with effect from 2020. The resulting monetary foreign exchange loss in respect of the impact of hyperinflation in Lebanon was recognized in the Sanofi financial statements as of December 31, 2020, and is immaterial. In 2020, Sanofi continued to account for subsidiaries based in Venezuela using the full consolidation method, on the basis that the criteria for control as specified in IFRS 10 (Consolidated Financial Statements) are still met. In 2018, the Venezuelan government made further changes to the foreign exchange system. At the end of August 2018 the “DICOM” rate, which had been the compulsory rate since the end of January 2018, was abolished and replaced by the “PETRO” rate with a floating US dollar/bolivar parity. At the same time, the strong bolivar (“VEF”) was also replaced by a new currency known as the sovereign bolivar (“VES”), reflecting a 1-for-100,000 devaluation. Consequently, the contribution of the Venezuelan subsidiaries to the consolidated financial statements is immaterial. In Argentina, the cumulative rate of inflation over the last three years is in excess of 100%, based on a combination of indices used to measure inflation in that country. Consequently, Sanofi has treated Argentina as a hyperinflationary economy from July 1, 2018 onwards, and applies IAS 29. As a result, an immaterial monetary foreign exchange loss was recognized in the Sanofi financial statements as of December 31, 2020, December 31, 2019 and December 31, 2018 in respect of the impact of hyperinflation in Argentina.
Withdrawal of the United Kingdom from the European Union	Withdrawal of the United Kingdom from the European UnionThe withdrawal of the United Kingdom from the European Union does not pose any major issues for Sanofi, and Sanofi does not expect a material impact on the consolidated financial statements.
Covid-19 pandemic	Covid-19 pandemic Covid-19, confirmed as a pandemic by the World Health Organization on March 11, 2020, has led to a global health crisis. Sanofi has assessed the impact of the uncertainties created by the pandemic. As of December 31, 2020, those uncertainties have not appreciably called into question the estimates and assumptions made by management (see Note A.3.). Sanofi will continue to reassess those estimates and assumptions as the situation evolves. Effect of the Covid-19 pandemic on the valuation of goodwill and other intangible assets In accordance with IAS 36 (Impairment of Assets), Sanofi conducts impairment tests on goodwill allocated to each of its cash generating units and on other intangible assets not yet available for use (such as capitalized in-process research and development) on an annual basis, regardless of whether there is an indication they might have become impaired (see Notes B.6. and D.5.). The impairment tests conducted as of December 31, 2020 found no indications of potential impairment. Sanofi also conducted impairment tests on certain intangible assets as a result of specific circumstances not directly related to the Covid-19 pandemic; the outcomes of those tests are described in Note D.5. Effect of the Covid-19 pandemic on accounts receivable As of December 31, 2020, Sanofi estimated the value of its accounts receivable using the expected loss method (see Note B.8.1.). Nothing was identified that would indicate a material increase in expected credit risk, especially as regards Sanofi’s principal customers (see Note D.34.). Effect of the Covid-19 pandemic on the liquidity position The Covid-19 pandemic has not had a negative impact on Sanofi’s liquidity position. Effect of the Covid-19 pandemic on the presentation of the income statement
Agreements relating to the recombinant Covid-19 vaccine candidate developed by Sanofi in collaboration with GSK	Agreements relating to the recombinant Covid-19 vaccine candidate developed by Sanofi in collaboration with GSK On February 18, 2020, Sanofi and the US Department of Health and Human Services extended their research and development partnership to leverage Sanofi’s previous development work on a SARS vaccine to attempt to unlock a fast path forward for developing a Covid-19 vaccine. Under the terms of the collaboration, the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response within the US Department of Health and Human Services, is helping to fund the research and development undertaken by Sanofi. Sanofi has recognized the BARDA funding as a deduction from the research and development expenses incurred, in accordance with IAS 20 (Accounting for Government Grants and Disclosure of Government Assistance). The amount of government assistance received and expenses incurred in 2020 is immaterial. On April 14, 2020, Sanofi and GlaxoSmithKline (GSK) entered into a collaboration agreement to develop a recombinant Covid-19 vaccine candidate, with Sanofi contributing its S‑protein Covid-19 antigen (based on recombinant DNA technology) and GSK contributing its pandemic adjuvant technology. Sanofi is leading clinical development and the registration process for the vaccine. On July 31, 2020, the recombinant Covid-19 vaccine candidate developed by Sanofi in collaboration with GSK was selected by the US government’s Operation Warp Speed (OWS) program. Under the OWS, the US government is providing funds to support further development of the vaccine, including clinical trials and scaling-up of manufacturing capacity. The agreement also provides for the supply of 100 million doses of the vaccine, with payment due at the time vaccine doses are provided. Sanofi has recognized the funding received from the US government as a deduction from (i) the development expenses incurred or (ii) the acquisition cost of property, plant and equipment acquired, in accordance with IAS 20 (Accounting for Government Grants and Disclosure of Government Assistance). As regards delivery of the 100 million vaccine doses, Sanofi considers this to be a contract with a customer, to be accounted for in accordance with IFRS 15 (Revenue from Contracts with Customers). In September 2020, Sanofi and GSK signed pre-order contracts with the Canadian and UK governments and with the European Union for doses of the vaccine candidate. As of the date of signature, those contracts do not constitute a firm commitment to purchase since the governments and the EU can decide whether or not to proceed with their purchase based on the results of the clinical trial. If the pre-orders are confirmed, the amounts received by Sanofi on the date of signature of the pre-order contracts will be deducted from the amount due in respect of the firm order for the vaccines. In accordance with IFRS 15 (see Note B.13.1.), Sanofi recognizes revenue when control over the product is transferred to the customer (for vaccines, transfer of control is usually determined by reference to the terms of release and acceptance of batches of vaccine). The total amount received by Sanofi on signature of the vaccine pre-order contracts was €252 million. In accordance with IFRS 15, those payments are customer contract liabilities (i.e. an obligation for the entity to supply goods to a customer, for which consideration has been received from the customer). They are presented within “Customer contract liabilities” in the balance sheet (see Note D.19.5.), and within “Net change in other current assets and other current liabilities” in the statement of cash flows. On December 11, 2020, Sanofi and GSK published interim clinical trial results showing an immune response comparable to patients who recovered from Covid-19 in adults aged 18 to 49 years, but an insufficient response in older adults. The two companies reaffirmed their intention to ongoing development of the vaccine candidate but decided to initiate a Phase IIb study with an improved antigen formulation in the first quarter of 2021 in order to provide high-level immune response across all age groups. As of December 31, 2020 this new stage in the development of the vaccine candidate had not altered the funding commitments made by the US government, or the pre-orders placed by Canada, the UK and the EU.
Basis of consolidation	Basis of consolidation In accordance with IFRS 10 (Consolidated Financial Statements), the consolidated financial statements of Sanofi include the financial statements of entities that Sanofi controls directly or indirectly, regardless of the level of the equity interest in those entities. An entity is controlled when Sanofi has power over the entity, exposure or rights to variable returns from its involvement with the entity, and the ability to affect those returns through its power over the entity. In determining whether control exists, potential voting rights must be taken into account if those rights are substantive, in other words they can be exercised on a timely basis when decisions about the relevant activities of the entity are to be taken. Entities consolidated by Sanofi are referred to as “subsidiaries”. Entities that Sanofi controls by means other than voting rights are referred to as “consolidated structured entities”. In accordance with IFRS 11 (Joint Arrangements), Sanofi classifies its joint arrangements (i.e. arrangements in which Sanofi exercises joint control with one or more other parties) either as a joint operation or a joint venture. In the case of a joint operation, Sanofi recognizes the assets and liabilities of the operation in proportion to its rights and obligations relating to those assets and liabilities. Joint ventures are accounted for using the equity method. Sanofi exercises joint control over a joint arrangement when decisions relating to the relevant activities of the arrangement require the unanimous consent of Sanofi and the other parties with whom control is shared. Sanofi exercises significant influence over an entity when it has the power to participate in the financial and operating policy decisions of that entity, but does not have the power to exercise control or joint control over those policies. In accordance with IAS 28 (Investments in Associates and Joint Ventures), the equity method is used to account for joint ventures (i.e. entities over which Sanofi exercises joint control) and for associates (i.e. entities over which Sanofi exercises significant influence). Under the equity method, the investment is initially recognized at cost, and subsequently adjusted to reflect changes in the net assets of the associate or joint venture. IAS 28 does not specify the treatment to be adopted on first-time application of the equity method to an investee following a step acquisition. Consequently, by reference to paragraph 10 of IAS 28, Sanofi has opted to apply the cost method, whereby the carrying amount of the investment represents the sum of the historical cost amounts for each step in the acquisition. As of the date on which the equity method is first applied, goodwill (which is included in the carrying amount of the investment) is determined for each acquisition step. The same applies to subsequent increases in the percentage interest in the equity-accounted investment. When the criteria of IFRS 5 are met, Sanofi recognizes the equity interest within the balance sheet line item Assets held for sale or exchange . The equity method is not applied to equity interests that are classified as held-for-sale assets. Transactions between consolidated companies are eliminated, as are intragroup profits. A list of the principal companies included in the consolidation in 2020 is presented in Note F.
Foreign currency translation	Foreign currency translation B.2.1. Accounting for foreign currency transactions in the financial statements of consolidated entities Non-current assets (other than receivables) and inventories acquired in foreign currencies are translated into the functional currency using the exchange rate prevailing at the acquisition date. Monetary assets and liabilities denominated in foreign currencies are translated using the exchange rate prevailing at the end of the reporting period. The gains and losses resulting from foreign currency translation are recorded in the income statement. However, foreign exchange gains and losses arising from the translation of advances between consolidated subsidiaries for which settlement is neither planned nor likely to occur in the foreseeable future are recognized in equity, in the line item Change in currency translation differences . B.2.2. Foreign currency translation of the financial statements of foreign entities Sanofi presents its consolidated financial statements in euros (€). In accordance with IAS 21 (The Effects of Changes in Foreign Exchange Rates), each subsidiary accounts for its transactions in the currency that is most representative of its economic environment (the functional currency). All assets and liabilities are translated into euros using the exchange rate of the subsidiary’s functional currency prevailing at the end of the reporting period. Income statements are translated using a weighted average exchange rate for the period, except in the case of foreign subsidiaries in a hyperinflationary economy. The resulting currency translation difference is recognized as a separate component of equity in the consolidated statement of comprehensive income, and is recognized in the income statement only when the subsidiary is sold or is wholly or partially liquidated.
Business combinations and transactions with non-controlling interests	Business combinations and transactions with non-controlling interests B.3.1. Accounting for business combinations, transactions with non-controlling interests and loss of control Business combinations are accounted for in accordance with IFRS 3 (Business Combinations) and IFRS 10 (Consolidated Financial Statements). Business combinations are accounted for using the acquisition method. Under this method, the acquiree’s identifiable assets and liabilities that satisfy the recognition criteria of IFRS 3 (Business Combinations) are measured initially at their fair values at the date of acquisition, except for (i) non-current assets classified as held for sale (which are measured at fair value less costs to sell) and (ii) assets and liabilities that fall within the scope of IAS 12 (Income Taxes) and IAS 19 (Employee Benefits). Restructuring liabilities are recognized as a liability of the acquiree only if the acquiree has an obligation as of the acquisition date to carry out the restructuring. The principal accounting rules applicable to business combinations and transactions with non-controlling interests include: • Acquisition-related costs are recognized as an expense on the acquisition date, as a component of Operating income . • Contingent consideration is recognized in equity if the contingent payment is settled by delivery of a fixed number of the acquirer’s equity instruments; otherwise, it is recognized in Liabilities related to business combinations . Contingent consideration is recognized at fair value at the acquisition date irrespective of the probability of payment. If the contingent consideration was originally recognized as a financial liability, subsequent adjustments to the liability are recognized in profit or loss in the line item Fair value remeasurement of contingent consideration , unless the adjustment is made within the twelve months following the acquisition date and relates to facts and circumstances existing as of that date. • Goodwill may be calculated on the basis of either (i) the entire fair value of the acquiree, or (ii) a share of the fair value of the acquiree proportionate to the interest acquired. This option is elected for each acquisition individually. Purchase price allocations are performed under the responsibility of management, with assistance from an independent valuer in the case of major acquisitions. IFRS 3 does not specify an accounting treatment for contingent consideration arising from a business combination made by an entity prior to the acquisition of control in that entity and carried as a liability in the acquired entity’s balance sheet. The accounting treatment applied by Sanofi to such a liability is to measure it at fair value as of the acquisition date and to report it in the line item Liabilities related to business combinations and to non-controlling interests , with subsequent remeasurements recognized in profit or loss. This treatment is consistent with the accounting applied to contingent consideration in the books of the acquirer. B.3.2. Goodwill The excess of the cost of an acquisition over Sanofi’s interest in the fair value of the identifiable assets and liabilities of the acquiree is recognized as goodwill at the date of the business combination. Goodwill arising on the acquisition of subsidiaries is shown in a separate balance sheet line item, whereas goodwill arising on the acquisition of investments accounted for using the equity method is recorded in Investments accounted for using the equity method . Goodwill arising on foreign operations is expressed in the functional currency of the country concerned and translated into euros using the exchange rate prevailing at the end of the reporting period. In accordance with IAS 36 (Impairment of Assets), goodwill is carried at cost less accumulated impairment (see Note B.6.). Goodwill is tested for impairment annually and whenever events or circumstances indicate that impairment might exist. Such events or circumstances include significant changes more likely than not to have an other-than-temporary impact on the substance of the original investment.
Other intangible assets	Other intangible assets Other intangible assets are initially measured at acquisition cost or production cost, including any directly attributable costs of preparing the asset for its intended use, or (in the case of assets acquired in a business combination) at fair value as of the date of the business combination. Intangible assets are amortized on a straight line basis over their useful lives. The useful lives of other intangible assets are reviewed at the end of each reporting period. The effect of any adjustment to useful lives is recognized prospectively as a change in accounting estimate. Amortization of other intangible assets is recognized in the income statement within Amortization of intangible assets except for amortization charged against (i) acquired or internally-developed software and (ii) other rights of an industrial or operational nature, which is recognized in the relevant classification of expense by function. Sanofi does not own any intangible assets with an indefinite useful life, other than goodwill. Intangible assets (other than goodwill) are carried at cost less accumulated amortization and accumulated impairment, if any, in accordance with IAS 36 (see Note B.6.). B.4.1. Research and development not acquired in a business combination Internally generated research and development Under IAS 38, research expenses are recognized in profit or loss when incurred. Internally generated development expenses are recognized as an intangible asset if, and only if, all the following six criteria can be demonstrated: (a) the technical feasibility of completing the development project; (b) Sanofi’s intention to complete the project; (c) Sanofi’s ability to use the project; (d) the probability that the project will generate future economic benefits; (e) the availability of adequate technical, financial and other resources to complete the project; and (f) the ability to measure the development expenditure reliably. Due to the risks and uncertainties relating to regulatory approval and to the research and development process, the six criteria for capitalization are usually considered not to have been met until the product has obtained marketing approval from the regulatory authorities. Consequently, internally generated development expenses arising before marketing approval has been obtained, mainly the cost of clinical trials, are generally expensed as incurred within Research and development expenses . Some industrial development expenses (such as those incurred in developing a second-generation synthesis process) are incurred after marketing approval has been obtained, in order to improve the industrial process for an active ingredient. To the extent that the six IAS 38 criteria are considered as having been met, such expenses are recognized as an asset in the balance sheet within Other intangible assets as incurred. Similarly, some clinical trials, for example those undertaken to obtain a geographical extension for a molecule that has already obtained marketing approval in a major market, may in certain circumstances meet the six capitalization criteria under IAS 38, in which case the related expenses are recognized as an asset in the balance sheet within Other intangible assets . Separately acquired research and development Payments for separately acquired research and development are capitalized within Other intangible assets provided that they meet the definition of an intangible asset: a resource that is (i) controlled by Sanofi, (ii) expected to provide future economic benefits for Sanofi, and (iii) identifiable (i.e. it is either separable or arises from contractual or legal rights). Under paragraph 25 of IAS 38, the first condition for capitalization (the probability that the expected future economic benefits from the asset will flow to the entity) is considered to be satisfied for separately acquired research and development. Consequently, upfront and milestone payments to third parties related to pharmaceutical products for which marketing approval has not yet been obtained are recognized as intangible assets, and amortized on a straight line basis over their useful lives beginning when marketing approval is obtained. Payments under research and development arrangements relating to access to technology or to databases, and payments made to purchase generics dossiers, are also capitalized, and amortized over the useful life of the intangible asset. Subcontracting arrangements, payments for research and development services, and continuous payments under research and development collaborations which are unrelated to the outcome of that collaboration, are expensed over the service term. B.4.2. Other intangible assets not acquired in a business combination Licenses other than those related to pharmaceutical products and research projects, in particular software licenses, are capitalized at acquisition cost, including any directly attributable cost of preparing the software for its intended use. Software licenses are amortized on a straight line basis over their useful lives for Sanofi ( three Internally generated costs incurred to develop or upgrade software are capitalized if the IAS 38 recognition criteria are satisfied, and amortized on a straight line basis over the useful life of the software from the date on which the software is ready for use. B.4.3. Other intangible assets acquired in a business combination Other intangible assets acquired in a business combination which relate to in-process research and development and currently marketed products and are reliably measurable are identified separately from goodwill, measured at fair value, and capitalized within Other intangible assets in accordance with IFRS 3 (Business Combinations) and IAS 38 (Intangible Assets). The related deferred tax liability is also recognized if a deductible or taxable temporary difference exists. In-process research and development acquired in a business combination is amortized on a straight line basis over its useful life from the date of receipt of marketing approval. Rights to products currently marketed by Sanofi are amortized on a straight line basis over their useful lives, determined on the basis of cash flow forecasts which take into account the patent protection period of the marketed product.
Property, plant and equipment owned and leased	Property, plant and equipment owned and leased B.5.1. Property, plant and equipment owned Property, plant and equipment is initially measured and recognized at acquisition cost, including any directly attributable cost of preparing the asset for its intended use, or (in the case of assets acquired in a business combination) at fair value as of the date of the business combination. The component-based approach to accounting for property, plant and equipment is applied. Under this approach, each component of an item of property, plant and equipment with a cost which is significant in relation to the total cost of the item and which has a different useful life from the other components must be depreciated separately. After initial measurement, property, plant and equipment is carried at cost less accumulated depreciation and impairment, except for land which is carried at cost less impairment. Subsequent costs are not recognized as assets unless (i) it is probable that future economic benefits associated with those costs will flow to Sanofi and (ii) the costs can be measured reliably. Borrowing costs attributable to the financing of items of property, plant and equipment, and incurred during the construction period, are capitalized as part of the acquisition cost of the item. Government grants relating to property, plant and equipment are deducted from the acquisition cost of the asset to which they relate. The depreciable amount of items of property, plant and equipment, net of any residual value, is depreciated on a straight line basis over the useful life of the asset. The useful life of an asset is usually equivalent to its economic life. The customary useful lives of property, plant and equipment are as follows: Buildings 15 to 40 years Fixtures 10 to 20 years Machinery and equipment 5 to 15 years Other 3 to 15 years Useful lives and residual values of property, plant and equipment are reviewed annually. The effect of any adjustment to useful lives or residual values is recognized prospectively as a change in accounting estimate. Depreciation of property, plant and equipment is recognized as an expense in the income statement, in the relevant classification of expense by function. B.5.2. Property, plant and equipment leased Effective from January 1, 2019 leases contracted by Sanofi have been accounted for in accordance with IFRS 16 (Leases). Sanofi recognizes a right-of-use asset and a lease liability for all of its lease contracts, except for (i) leases relating to low-value assets and (ii) short-term leases (12 months or less). Payments made in respect of leases not recognized on the balance sheet are recognized as an operating expense on a straight line basis over the lease term. On commencement of a lease, the liability for future lease payments is discounted at the incremental borrowing rate, which is a risk-free rate adjusted to reflect the specific risk profile of each Sanofi entity. Because lease payments are spread over the lease term, Sanofi applies a discount rate based on the duration of those payments. The payments used to determine the liability for future lease payments exclude non-lease components, but include fixed payments that Sanofi expects to make to the lessor over the estimated lease term. After commencement of the lease, the liability for future lease payments is reduced by the amount of the lease payments made, and increased to reflect interest on the liability. In the event of a reassessment or modification of future lease payments, the lease liability is remeasured. The right-of-use asset - which is initially measured at cost including direct costs of the lessee, prepayments made at or prior to the commencement date, less lease incentives received and restoration costs - is depreciated on a straight line basis over the lease term, and tested for impairment as required. Sanofi recognizes deferred taxes in respect of right-of-use assets and lease liabilities. Leasehold improvements are depreciated over their economic life, which is capped at the lease term as determined under IFRS 16.
Impairment of property, plant and equipment, intangible assets, and investments accounted for using the equity method	Impairment of property, plant and equipment, intangible assets, and investments accounted for using the equity method B.6.1. Impairment of property, plant and equipment and intangible assets In accordance with IAS 36 (Impairment of Assets), assets that generate separate cash flows and assets included in cash-generating units (CGUs) are assessed for impairment when events or changes in circumstances indicate that the asset or CGU may be impaired. A CGU is the smallest identifiable group of assets that generates cash inflows that are largely independent of the cash inflows from other assets or groups of assets. Under IAS 36, each CGU or group of CGUs to which goodwill is allocated must (i) represent the lowest level within the entity at which the goodwill is monitored for internal management purposes, and (ii) not be larger than an operating segment determined in accordance with IFRS 8 (Operating Segments), before application of the IFRS 8 aggregation criteria (see Note B.26.). Quantitative and qualitative indications of impairment (primarily relating to the status of the research and development portfolio, pharmacovigilance, patent litigation, and the launch of competing products) are reviewed at the end of each reporting period. If there is any internal or external indication of impairment, Sanofi estimates the recoverable amount of the asset or CGU. Other intangible assets not yet available for use (such as capitalized in-process research and development), and CGUs or groups of CGUs that include goodwill, are tested for impairment annually whether or not there is any indication of impairment, and more frequently if any event or circumstance indicates that they might be impaired. Such assets are not amortized. When there is an internal or external indication of impairment, Sanofi estimates the recoverable amount of the asset and recognizes an impairment loss if the carrying amount of the asset exceeds its recoverable amount. The recoverable amount of the asset is the higher of its fair value less costs to sell or its value in use. To determine value in use, Sanofi uses estimates of future cash flows generated by the asset or CGU, prepared using the same methods as those used in the initial measurement of the asset or CGU on the basis of medium-term strategic plans. In the case of goodwill, estimates of future cash flows are based on a five-year strategic plan, an extrapolation of the cash flows over a further five-year period, and a terminal value. In the case of other intangible assets, the period used is based on the economic life of the asset. Estimated cash flows are discounted at long-term market interest rates that reflect the best estimate by Sanofi of the time value of money, the risks specific to the asset or CGU, and economic conditions in the geographical regions in which the business activity associated with the asset or CGU is located. Certain assets and liabilities that are not directly attributable to a specific CGU are allocated between CGUs on a basis that is reasonable, and consistent with the allocation of the corresponding goodwill. Impairment losses arising on property, plant and equipment, on software and on certain rights are recognized in the relevant classification of expense by function. Impairment losses arising on other intangible assets are recognized within Impairment of intangible assets in the income statement. B.6.2. Impairment of investments accounted for using the equity method In accordance with IAS 28 (Investments in Associates and Joint Ventures), Sanofi determines whether investments accounted for using the equity method may be impaired based on indicators such as default in contractual payments, significant financial difficulties, probability of bankruptcy, or a prolonged or significant decline in quoted market price. If an investment is impaired, the amount of the impairment loss is determined by applying IAS 36 (see Note B.6.1.) and recognized in Share of profit/(loss) from investments accounted for using the equity method . B.6.3. Reversals of impairment losses charged against property, plant and equipment, intangible assets, and investments accounted for using the equity method At the end of each reporting period, Sanofi assesses whether events or changes in circumstances indicate that an impairment loss recognized in a prior period in respect of an asset (other than goodwill) or an investment accounted for using the equity method can be reversed. If this is the case, and the recoverable amount as determined based on the revised estimates exceeds the carrying amount of the asset, Sanofi reverses the impairment loss only to the extent of the carrying amount that would have been determined had no impairment loss been recognized for the asset. Reversals of impairment losses in respect of other intangible assets are recognized within the income statement line item Impairment of intangible assets , while reversals of impairment losses in respect of investments accounted for using the equity method are recognized within the income statement line item Share of profit/(loss) from investments accounted for using the equity method . Impairment losses taken against goodwill are never reversed, unless the goodwill is part of the carrying amount of an investment accounted for using the equity method.
Assets held for sale or exchange and liabilities related to assets held for sale or exchange	Assets held for sale or exchange and liabilities related to assets held for sale or exchange In accordance with IFRS 5 (Non-Current Assets Held for Sale and Discontinued Operations), non-current assets and groups of assets are classified as held for sale in the balance sheet if their carrying amount will be recovered principally through a sale transaction rather than through continuing use. Within the meaning of IFRS 5, the term “sale” also includes exchanges for other assets. Non-current assets or asset groups held for sale must be available for immediate sale in their present condition, subject only to terms that are usual and customary for sales of such assets, and a sale must be highly probable. Criteria used to determine whether a sale is highly probable include: • the appropriate level of management must be committed to a plan to sell; • an active program to locate a buyer and complete the plan must have been initiated; • the asset must be actively marketed for sale at a price that is reasonable in relation to its current fair value; • completion of the sale should be foreseeable within the twelve months following the date of reclassification to Assets held for sale or exchange ; and • actions required to complete the plan should indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Before initial reclassification of the non-current asset (or asset group) to Assets held for sale or exchange , the carrying amounts of the asset (or of all the assets and liabilities in the asset group) must be measured in accordance with the applicable standards. Subsequent to reclassification to Assets held for sale or exchange , the non-current asset (or asset group) is measured at the lower of carrying amount or fair value less costs to sell, with any write-down recognized by means of an impairment loss. Once a non-current asset has been reclassified as held for sale or exchange, it is no longer depreciated or amortized. In a disposal of an equity interest leading to loss of control, all the assets and liabilities of the entity involved are classified as held-for-sale assets or liabilities within the balance sheet line items Assets held for sale or exchange or Liabilities related to assets held for sale or exchange , provided that the disposal satisfies the IFRS 5 classification criteria. The profit or loss generated by a held-for-sale asset group is reported in a separate line item in the income statement for the current period and for the comparative periods presented, provided that the asset group: • represents a separate major line of business or geographical area of operations; or, • is part of a single coordinated plan to dispose of a separate major line of business or geographical area of operations; or, • is a subsidiary acquired exclusively with a view to resale. In accordance with IFRS 10, transactions between companies that are held for sale or treated as discontinued operations and other consolidated companies are eliminated. Events or circumstances beyond Sanofi’s control may extend the period to complete the sale or exchange beyond one year without precluding classification of the asset (or disposal group) in Assets held for sale or exchange provided that there is sufficient evidence that Sanofi remains committed to the planned sale or exchange. Finally, in the event of changes to a plan of sale that requires an asset no longer to be classified as held for sale, IFRS 5 specifies the following treatment: • The assets and liabilities previously classified as held for sale are reclassified to the appropriate balance sheet line items, with no restatement of comparative periods. • Each asset is measured at the lower of (a) its carrying amount before the asset was reclassified as held for sale, adjusted for any depreciation, amortization or revaluation that would have been recognized if the asset had not been reclassified as held for sale, or (b) its recoverable amount at the date of reclassification. • The backlog of depreciation, amortization and impairment not recognized while non-current assets were classified as held for sale must be reported in the same income statement line item that was used to report impairment losses arising on initial reclassification of assets as held for sale and gains or losses arising on the sale of such assets. In the consolidated income statement, those impacts are reported within the line item Other gains and losses, and litigation . • The net income of a business previously classified as discontinued or as held for sale or exchange and reported on a separate line in the income statement must be reclassified and included in net income from continuing operations, for all periods presented. • In addition, segment information relating to the income statement and the statement of cash flows (acquisitions of non-current assets) must be disclosed in the notes to the financial statements in accordance with IFRS 8 (Operating Segments), and must also be restated for all prior periods presented.
Financial instruments	Financial instruments B.8.1. Non-derivative financial assets In accordance with IFRS 9 (Financial Instruments) and IAS 32 (Financial Instruments: Presentation), Sanofi has adopted the classification of non-derivative financial assets described below. The classification used depends on (i) the characteristics of the contractual cash flows (i.e. whether they represent interest or principal) and (ii) the business model for managing the asset applied at the time of initial recognition. Financial assets at fair value through other comprehensive income These mainly comprise: • quoted and unquoted equity investments that Sanofi does not hold for trading purposes and that management has designated at “fair value through other comprehensive income” on initial recognition. Gains and losses arising from changes in fair value are recognized in equity within the statement of comprehensive income in the period in which they occur. When such instruments are derecognized, the previously-recognized changes in fair value remain within Other comprehensive income , as does the gain or loss on divestment. Dividends received are recognized in profit or loss for the period, within the line item Financial income ; and • debt instruments whose contractual cash flows represent payments of interest or repayments of principal, and which are managed with a view to collecting cash flows and selling the asset. Gains and losses arising from changes in fair value are recognized in equity within the statement of comprehensive income in the period in which they occur. When such assets are derecognized, the cumulative gains and losses previously recognized in equity are reclassified to profit or loss for the period within the line items Financial income or Financial expenses . Financial assets at fair value through profit or loss These mainly comprise: • contingent consideration already carried in the books of an acquired entity or granted in connection with a business combination; • instruments whose contractual cash flows represent payments of interest and repayments of principal, which are managed with a view to selling the asset; • instruments that management has designated at “fair value through profit or loss” on initial recognition; and • quoted and unquoted equity investments: equity instruments that are not held for trading and which management did not designate at “fair value through other comprehensive income” on initial recognition, and instruments that do not meet the IFRS definition of “equity instruments”. Gains and losses arising from changes in fair value are recognized in profit or loss within the line items Financial income or Financial expenses . Dividends received are recognized in profit or loss for the period, within the line item Financial income . Fair value of equity investments in unquoted entities On initial recognition of an equity investment in an entity not quoted in an active market, the fair value of the investment is the acquisition cost. Cost ceases to be a representative measure of the fair value of an unquoted equity investment when Sanofi identifies significant changes in the investee, or in the environment in which it operates. In such cases, an internal valuation is carried out, based mainly on growth forecasts or by reference to similar transactions contracted with third parties. Financial assets measured at amortized cost Financial assets at amortized cost comprise instruments whose contractual cash flows represent payments of interest and repayments of principal and which are managed with a view to collecting cash flows. The main assets in this category are loans and receivables. They are presented within the line items Other non-current assets , Other current assets , Accounts receivable and Cash and cash equivalents . Loans with a maturity of more than 12 months are presented in “Long-term loans and advances” within Other non-current assets . These financial assets are measured at amortized cost using the effective interest method. Impairment of financial assets measured at amortized cost The main assets involved are accounts receivable. Accounts receivable are initially recognized at the amount invoiced to the customer. Impairment losses on trade accounts receivable are estimated using the expected loss method, in order to take account of the risk of payment default throughout the lifetime of the receivables. The expected credit loss is estimated collectively for all accounts receivable at each reporting date using an average expected loss rate, determined primarily on the basis of historical credit loss rates. However, that average expected loss rate may be adjusted if there are indications of a likely significant increase in credit risk. If a receivable is subject to a known credit risk, a specific impairment loss is recognized for that receivable. The amount of expected losses is recognized in the balance sheet as a reduction in the gross amount of accounts receivable. Impairment losses on accounts receivable are recognized within Selling and general expenses in the income statement. B.8.2. Derivative instruments Derivative instruments that do not qualify for hedge accounting are initially and subsequently measured at fair value, with changes in fair value recognized in the income statement in Other operating income or in Financial income or Financial expenses , depending on the nature of the underlying economic item which is hedged. Derivative instruments that qualify for hedge accounting are measured using the policies described in Note B.8.3. below. IFRS 13 (Fair Value Measurement) requires counterparty credit risk to be taken into account when measuring the fair value of financial instruments. That risk is estimated on the basis of observable, publicly-available statistical data. Policy on offsetting In order for a financial asset and a financial liability to be presented as a net amount in the balance sheet under IAS 32, there must be: (a) a legally enforceable right to offset; and (b) the intention either to settle on a net basis, or to realize the asset and settle the liability simultaneously. B.8.3. Hedging As part of its overall market risk management policy, Sanofi enters into various hedging transactions involving derivative or non-derivative instruments; these may include forward contracts, currency swaps or options, interest rate swaps or options, cross-currency swaps, and debt placings or issues. Such financial instruments are designated as hedging instruments and recognized using the hedge accounting principles of IFRS 9 when (a) there is formal designation and documentation of the hedging relationship, of how the effectiveness of the hedging relationship will be assessed, and of the underlying market risk management objective and strategy; (b) the hedged item and the hedging instrument are eligible for hedge accounting; and (c) there is an economic relationship between the hedged item and the hedging instrument, defined on the basis of a hedge ratio that is consistent with the underlying market risk management strategy, and the residual credit risk does not dominate the value changes that result from that economic relationship. Fair value hedge A fair value hedge is a hedge of the exposure to changes in fair value of an asset, liability or firm commitment that is attributable to one or more risk components and could affect profit or loss. Changes in fair value of the hedging instrument and changes in fair value of the hedged item attributable to the hedged risk components are generally recognized in the income statement, within Other operating income for hedges related to operating activities, or within Financial income or Financial expenses for hedges related to investing or financing activities. Cash flow hedge A cash flow hedge is a hedge of the exposure to variability in cash flows from an asset, liability or highly probable forecast transaction that is attributable to one or more risk components and could affect profit or loss. Changes in fair value of the hedging instrument attributable to the effective portion of the hedge are recognized directly in equity in the consolidated statement of comprehensive income. Changes in fair value attributable to the ineffective portion of the hedge are recognized in the income statement within Other operating income for hedges related to operating activities, and within Financial income or Financial expenses for hedges related to investing or financing activities. Cumulative changes in fair value of the hedging instrument previously recognized in equity are reclassified to the income statement when the hedged transaction affects profit or loss. Those reclassified gains and losses are recognized within Other operating income for hedges related to operating activities, and within Financial income or Financial expenses for hedges related to investing or financing activities. When a forecast transaction results in the recognition of a non-financial asset or liability, cumulative changes in the fair value of the hedging instrument previously recognized in equity are incorporated in the initial carrying amount of that asset or liability. When the hedging instrument expires or is sold, terminated or exercised, the cumulative gain or loss previously recognized in equity remains separately recognized in equity and is not reclassified to the income statement, or recognized as an adjustment to the initial cost of the related non-financial asset or liability, until the forecast transaction occurs. However, if Sanofi no longer expects the forecast transaction to occur, the cumulative gain or loss previously recognized in equity is recognized immediately in profit or loss. Hedge of a net investment in a foreign operation In a hedge of a net investment in a foreign operation, changes in the fair value of the hedging instrument attributable to the effective portion of the hedge are recognized directly in equity in the consolidated statement of comprehensive income. Changes in fair value attributable to the ineffective portion of the hedge are recognized in the income statement within Financial income or Financial expenses . When the investment in the foreign operation is sold, the changes in the fair value of the hedging instrument previously recognized in equity are reclassified to the income statement within Financial income or Financial expenses . Cost of hedging As part of its market risk management policy, Sanofi may designate currency options or interest rate options as hedging instruments, the effectiveness of which is measured on the basis of changes in intrinsic value. In such cases, the time value of the option is treated as a hedging cost and accounted for as follows: • If the option includes a component that is not aligned on the critical features of the hedged item, the corresponding change in the time value is taken to profit or loss. • Otherwise, the change in the time value is taken to equity within the statement of comprehensive income, and then: – if the hedged item is linked to a transaction that results in the recognition of a financial asset or liability, the change in the time value is reclassified to profit or loss symmetrically with the hedged item; or, – if the hedged item is linked to a transaction that results in the recognition of a non-financial asset or liability, the change in the time value is incorporated in the initial carrying amount of that asset or liability; or, – if the hedged item is linked to a period of time, the change in time value is reclassified to profit or loss on a straight line basis over the life of the hedging relationship. In the case of forward contracts and foreign exchange swaps, and of cross-currency swaps that qualify for hedge accounting on the basis of changes in spot rates, Sanofi may elect for each transaction to use the option whereby the premium/discount or foreign currency basis spread are treated in the same way as the time value of an option. Discontinuation of hedge accounting Hedge accounting is discontinued when the eligibility criteria are no longer met (in particular, when the hedging instrument expires or is sold, terminated or exercised), or if there is a change in the market risk management objective of the hedging relationship. B.8.4. Non-derivative financial liabilities Borrowings and debt Bank borrowings and debt instruments are initially measured at fair value of the consideration received, net of directly attributable transaction costs. Subsequently, they are measured at amortized cost using the effective interest method. All costs related to the issuance of borrowings or debt instruments, and all differences between the issue proceeds net of transaction costs and the value on redemption, are recognized within Financial expenses in the income statement over the term of the debt using the effective interest method. Liabilities related to business combinations and to non-controlling interests These line items record the fair value of (i) contingent consideration payable in connection with business combinations and (ii) commitments to buy out equity holders of subsidiaries, including put options granted to non-controlling interests. Adjustments to the fair value of commitments to buy out equity holders of subsidiaries, including put options granted to non-controlling interests, are recognized in equity. Other non-derivative financial liabilities Other non-derivative financial liabilities include trade accounts payable, which are measured at fair value (which in most cases equates to face value) on initial recognition, and subsequently at amortized cost. B.8.5. Fair value of financial instruments Under IFRS 13 (Fair Value Measurement) and IFRS 7 (Financial Instruments: Disclosures), fair value measurements must be classified using a hierarchy based on the inputs used to measure the fair value of the instrument. This hierarchy has three levels: (a) level 1: quoted prices in active markets for identical assets or liabilities (without modification or repackaging); (b) level 2: quoted prices in active markets for similar assets and liabilities, or valuation techniques in which all important inputs are derived from observable market data; and (c) level 3: valuation techniques in which not all important inputs are derived from observable market data. The table below shows the disclosures required under IFRS 7 relating to the measurement principles applied to financial instruments. Note Type of financial instrument Measurement Level in Valuation Method used to determine fair value Valuation Market data Exchange rate Interest D.7. Financial assets measured at fair value (quoted equity instruments) Fair value 1 Market value Quoted market price N/A D.7. Financial assets measured at fair value (quoted debt instruments) Fair value 1 Market value Quoted market price N/A D.7. Financial assets measured at fair value (unquoted equity instruments) Fair value 3 Revenue and/or market-based approach If cost ceases to be a representative measure of fair value, an internal valuation is carried out, based mainly on growth forecasts or by reference to similar transactions contracted with third parties. D.7. Financial assets measured at fair value (contingent consideration receivable) Fair value 3 Revenue-based approach The fair value of contingent consideration receivable is determined by adjusting the contingent consideration at the end of the reporting period using the method described in Note D.7.3. D.7. Financial assets measured at fair value held to meet obligations under post-employment benefit plans Fair value 1 Market value Quoted market price N/A D.7. Financial assets designated at fair value held to meet obligations under deferred compensation plans Fair value 1 Market value Quoted market price N/A D.7. Long-term loans and advances and other non-current receivables Amortized cost N/A N/A The amortized cost of long-term loans and advances and other non-current receivables at the end of the reporting period is not materially different from their fair value. D.13. Investments in mutual funds Fair value 1 Market value Net asset value N/A D.13. Negotiable debt instruments, commercial paper, instant access deposits and term deposits Amortized cost N/A N/A Because these instruments have a maturity of less than 3 months, amortized cost is regarded as an acceptable approximation of fair value as disclosed in the notes to the consolidated financial statements. D.17.1. Debt Amortized cost (a) N/A N/A In the case of debt with a maturity of less than 3 months, amortized cost is regarded as an acceptable approximation of fair value as reported in the notes to the consolidated financial statements. D.20. Forward currency contracts Fair value 2 Present value of future cash flows Mid < 1 year: Mid Money Market > 1 year: Mid Zero Coupon D.20. Interest rate swaps Fair value 2 Revenue-based approach Present value of future cash flows Mid < 1 year: D.20. Cross-currency swaps Fair value 2 Present value of future cash flows Mid < 1 year: D.18. Liabilities related to business combinations and to non-controlling interests (CVRs) Fair value 1 Market value Quoted market price D.18. Liabilities related to business combinations and to non-controlling interests (other than CVRs) Fair value (b) 3 Revenue-based approach Under IAS 32, contingent consideration payable in a business combination is a financial liability. The fair value of such liabilities is determined by adjusting the contingent consideration at the end of the reporting period using the method described in Note B.8.4. (a) In the case of debt designated as a hedged item in a fair value hedging relationship, the carrying amount in the consolidated balance sheet includes changes in fair value attributable to the hedged risk(s). (b) For business combinations completed prior to application of IFRS 3, contingent consideration is recognized when payment becomes probable. See Note B.3.1. The fair value of the Dexcom equity derivatives (see Note D.20.c.) is classified as Level 2 because the valuation is based on a generally accepted technique (the Black & Scholes model) that uses inputs from directly observable market parameters (share price, risk free rate and implied volatility). B.8.6. Derecognition of financial instruments Financial assets are derecognized when the contractual rights to cash flows from the asset have ended or have been transferred and when Sanofi has transferred substantially all the risks and rewards of ownership of the asset. If Sanofi has neither transferred nor retained substantially all the risks and rewards of ownership of a financial asset, it is derecognized if Sanofi does not retain control of the asset. A financial liability is derecognized when Sanofi’s contractual obligations in respect of the liability are discharged, cancelled or extinguished. B.8.7. Risks relating to financial instruments Market risks in respect of non-current financial assets, cash equivalents, derivative instruments and debt are described in the discussions of risk factors presented in Item 3.D. and Item 11. of Sanofi’s Annual Report on Form 20-F for 2020. Credit risk is the risk that customers may fail to pay their debts. For a description of credit risk, refer to "We are subject to the risk of non-payment by our customers" within Item 3.D. and Item 11. of Sanofi’s Annual Report on Form 20-F for 2020.
Inventories	Inventories Inventories are measured at the lower of cost or net realizable value. Cost is calculated using the weighted average cost method or the first-in, first-out method, depending on the nature of the inventory. The cost of finished goods inventories includes costs of purchase, costs of conversion and other costs incurred in bringing the inventories to their present location and condition. Net realizable value is the estimated selling price in the ordinary course of business less the estimated costs of completion and the estimated costs necessary to make the sale. During the launch phase of a new product, any inventories of that product are written down to zero pending regulatory approval. The write-down is reversed once it becomes highly probable that marketing approval will be obtained.
Cash and cash equivalents	Cash and cash equivalentsCash and cash equivalents as shown in the consolidated balance sheet and statement of cash flows comprise cash, plus liquid short-term investments that are readily convertible into cash and are subject to an insignificant risk of changes in value in the event of movements in interest rates.
Treasury shares	Treasury sharesIn accordance with IAS 32, Sanofi treasury shares are deducted from equity, irrespective of the purpose for which they are held. No gain or loss is recognized in the income statement on the purchase, sale, impairment or cancellation of treasury shares.
Provisions for risks	Provisions for risks In accordance with IAS 37 (Provisions, Contingent Liabilities and Contingent Assets), Sanofi records a provision when it has a present obligation, whether legal or constructive, as a result of a past event; it is probable that an outflow of resources embodying economic benefits will be required to settle the obligation; and a reliable estimate can be made of the amount of the outflow of resources. If the obligation is expected to be settled more than twelve months after the end of the reporting period, or has no definite settlement date, the provision is recorded within Non-current provisions and other non-current liabilities . Provisions relating to the insurance programs in which Sanofi’s captive insurance company participates are based on risk exposure estimates calculated by management, with assistance from independent actuaries, using IBNR (Incurred But Not Reported) techniques. Those techniques use past claims experience, within Sanofi and in the market, to estimate future trends in the cost of claims. Contingent liabilities are not recognized, but are disclosed in the notes to the financial statements unless the possibility of an outflow of economic resources is remote. Sanofi estimates provisions on the basis of events and circumstances related to present obligations at the end of the reporting period and of past experience, and to the best of management’s knowledge at the date of preparation of the financial statements. Reimbursements offsetting the probable outflow of resources are recognized as assets only if it is virtually certain that they will be received. Contingent assets are not recognized. Restructuring provisions are recognized if Sanofi has a detailed, formal restructuring plan at the end of the reporting period and has announced its intention to implement this plan to those affected by it. No provisions are recorded for future operating losses. Sanofi records non-current provisions for certain obligations, such as legal or constructive obligations, where an outflow of resources is probable and the amount of the outflow can be reliably estimated. In the case of environmental risks, including at sites where operations are ongoing, Sanofi recognizes a provision where there is a violation of integrity in respect of human health or the environment resulting from past contamination at a site that requires remediation. The amount of the provision is a best estimate of the future expenditures to be incurred on the remediation plan. Where the effect of the time value of money is material, those provisions are measured at the present value of the expenditures expected to be required to settle the obligation, calculated using a discount rate that reflects an estimate of the time value of money and the risks specific to the obligation. Increases in provisions to reflect the effects of the passage of time are recognized within Financial expenses .
Revenue recognition	Revenue recognition B.13.1. Net sales Revenue arising from the sale of goods is presented in the income statement within Net sales . Net sales comprise revenue from sales of pharmaceutical products, consumer healthcare products, active ingredients and vaccines, net of sales returns, of customer incentives and discounts, and of certain sales-based payments paid or payable to the healthcare authorities. Analyses of net sales are provided in Note D.35.1. “Segment Information”. In accordance with IFRS 15 (Revenue from Contracts with Customers), such revenue is recognized when Sanofi transfers control over the product to the customer; control of an asset refers to the ability to direct the use of, and obtain substantially all of the remaining benefits from that asset. For the vast majority of contracts, revenue is recognized when the product is physically transferred, in accordance with the delivery and acceptance terms agreed with the customer. For contracts entered into by Sanofi Pasteur, transfer of control is usually determined by reference to the terms of release (immediate or deferred) and acceptance of batches of vaccine. In the case of contracts with distributors, Sanofi does not recognize revenue when the product is physically transferred to the distributor if the products are sold on consignment, or if the distributor acts as agent. In such cases, revenue is recognized when control is transferred to the end customer, and the distributor’s commission is presented within the line item Selling and general expenses in the income statement. The amount of revenue recognized reflects the various types of price reductions or rights of return offered by Sanofi to its customers on certain products. Such price reductions and rights of return qualify as variable consideration under IFRS 15. In particular, products sold in the United States are covered by various Government and State programs (such as Medicare and Medicaid) under which products are sold at a discount. Rebates are granted to healthcare authorities, and under contractual arrangements with certain customers. Some wholesalers are entitled to chargeback incentives based on the selling price to the end customer, under specific contractual arrangements. Cash discounts may also be granted for prompt payment. Returns, discounts, incentives and rebates, as described above, are recognized in the period in which the underlying sales are recognized as a reduction of gross sales. These amounts are calculated as follows: • The amount of chargeback incentives is estimated on the basis of the relevant subsidiary’s standard sales terms and conditions, and in certain cases on the basis of specific contractual arrangements with the customer. • The amount of rebates based on attainment of sales targets is estimated and accrued as each of the underlying sales transactions is recognized. • The amount of price reductions under Government and State programs, largely in the United States, is estimated on the basis of the specific terms of the relevant regulations or agreements, and accrued as each of the underlying sales transactions is recognized. • The amount of sales returns is calculated on the basis of management’s best estimate of the amount of product that will ultimately be returned by customers. In countries where product returns are possible, Sanofi operates a returns policy that allows the customer to return products within a certain period either side of the expiry date (usually 12 months after the expiry date). The amount recognized for returns is estimated on the basis of past experience of sales returns. Sanofi also takes into account factors such as levels of inventory in its various distribution channels, product expiry dates, information about potential discontinuation of products, the entry of competing generics into the market, and the launch of over-the-counter medicines. Most product return clauses relate solely to date-expired products, which cannot be resold and are destroyed. Sanofi does not recognize a right of return asset in the balance sheet for contracts that allow for the return of time-expired products, since those products have no value. The estimated amounts described above are recognized in the income statement within Net sales as a reduction of gross sales, and within Other current liabilities in the balance sheet. They are subject to regular review and adjustment as appropriate based on the most recent data available to management. Sanofi believes that it has the ability to measure each of the above amounts reliably, using the following factors in developing its estimates: • the nature and patient profile of the underlying product; • the applicable regulations or the specific terms and conditions of contracts with governmental authorities, wholesalers and other customers; • historical data relating to similar contracts, in the case of qualitative and quantitative rebates and chargeback incentives; • past experience and sales growth trends for the same or similar products; • actual inventory levels in distribution channels, monitored by Sanofi using internal sales data and externally provided data; • the shelf life of Sanofi products; and • market trends including competition, pricing and demand. An analysis of provisions for discounts, rebates and sales returns is provided in Note D.23. B.13.2. Other revenues Other revenues mainly comprise royalties received from licensing intellectual property rights to third parties, and VaxServe sales of products sourced from third-party manufacturers. Royalties received under licensing arrangements are recognized over the period during which the underlying sales are recognized. VaxServe is a Vaccines segment entity whose operations include the distribution within the United States of vaccines and other products manufactured by third parties. VaxServe sales of products sourced from third-party manufacturers are presented within Other revenues .
Cost of sales	Cost of sales Cost of sales consists primarily of the industrial cost of goods sold, payments made under licensing agreements, and distribution costs. The industrial cost of goods sold includes the cost of materials, depreciation of property, plant and equipment, amortization of software, personnel costs, and other expenses attributable to production.
Research and development	Research and development Note B.4.1. “Research and development not acquired in a business combination” and Note B.4.3. “Other intangible assets acquired in a business combination” describe the principles applied to the recognition of research and development costs. Contributions or reimbursements received from alliance partners are recorded as a reduction of Research and development expenses .
Other operating income and expenses	Other operating income and expenses B.16.1. Other operating income Other operating income includes the share of profits that Sanofi is entitled to receive from alliance partners in respect of product marketing agreements. It also includes revenues generated under certain complex agreements, which may include partnership and co-promotion arrangements. This line item also includes realized and unrealized foreign exchange gains and losses on operating activities (see Note B.8.3.), and operating gains on disposals not regarded as major disposals (see Note B.20.). B.16.2. Other operating expenses Other operating expenses mainly comprise the share of profits that alliance partners are entitled to receive from Sanofi under product marketing agreements.
Amortization and impairment of intangible assets	Amortization and impairment of intangible assets B.17.1. Amortization of intangible assets The expenses recorded in this line item comprise amortization of product rights and other intangible assets (see Note D.4.), given that the benefit of those rights to Sanofi’s commercial, industrial and development functions cannot be separately identified. Amortization of software, and of other rights of an industrial or operational nature, is recognized as an expense in the income statement, in the relevant line items of expense by function. B.17.2. Impairment of intangible assets This line item records impairment losses (other than those associated with restructuring) recognized against intangible assets (including goodwill, but excluding software and other rights of an industrial or operational nature), and any reversals of such impairment losses.
Fair value remeasurement of contingent consideration	Fair value remeasurement of contingent consideration Changes in the fair value of contingent consideration that was (i) already carried in the books of an acquired entity, or (ii) granted in connection with a business combination and initially recognized as a liability in accordance with IFRS 3, are reported in profit or loss. Such adjustments are reported separately in the income statement, in the line item Fair value remeasurement of contingent consideration. This line item also includes changes in the fair value of contingent consideration receivable in connection with a divestment and classified as a financial asset at fair value through profit or loss. Finally, it includes the effect of the unwinding of discount, and of exchange rate movements where the asset or liability is expressed in a currency other than the functional currency of the reporting entity.
Restructuring costs and similar items	Restructuring costs and similar items Restructuring costs are expenses incurred in connection with the transformation or reorganization of Sanofi’s operations or support functions. Such costs include collective redundancy plans, compensation to third parties for early termination of contracts, and commitments made in connection with transformation or reorganization decisions. They also include accelerated depreciation charges arising from site closures (including closures of leased sites), and losses on asset disposals resulting from such decisions. In addition, this line item includes expenses incurred in connection with programs implemented as part of the transformation strategy announced in December 2019 (and previously in November 2015), and intended primarily to (i) deliver a global information systems solution; (ii) create a standalone Consumer Healthcare entity; and (iii) as announced on February 24, 2020, create a European leader in the production and marketing to third parties of active pharmaceutical ingredients (API).
Other gains and losses, and litigation	Other gains and losses, and litigation The line item Other gains and losses, and litigation includes the impact of material transactions of an unusual nature or amount which Sanofi believes it necessary to report separately in the income statement in order to improve the relevance of the financial statements, such as: • gains and losses on major disposals of property, plant and equipment, of intangible assets, of assets (or groups of assets and liabilities) held for sale, or of a business within the meaning of IFRS 3, other than those considered to be restructuring costs; • impairment losses and reversals of impairment losses on assets (or groups of assets and liabilities) held for sale, other than those considered to be restructuring costs; • gains on bargain purchases; • costs and provisions relating to major litigation; and • pre-tax separation costs associated with the process of disinvesting from operations in the event of a major divestment.
Financial expenses and income	Financial expenses and income B.21.1. Financial expenses Financial expenses mainly comprise interest charges on debt financing; negative changes in the fair value of financial instruments (where changes in fair value are recognized in profit or loss); realized and unrealized foreign exchange losses on financing and investing activities; impairment losses on financial instruments; and any reversals of impairment losses on financial instruments. Financial expenses also include expenses arising from the unwinding of discount on long-term provisions, and the net interest cost related to employee benefits. This line item does not include commercial cash discounts, which are deducted from net sales. B.21.2. Financial income Financial income includes interest and dividend income; positive changes in the fair value of financial instruments (where changes in fair value are recognized in profit or loss); realized and unrealized foreign exchange gains on financing and investing activities; and gains on disposals of financial assets at fair value through profit or loss.
Income tax expense	Income tax expense Income tax expense includes all current and deferred taxes of consolidated companies. Sanofi accounts for deferred taxes in accordance with IAS 12 (Income Taxes), using the methods described below: • Deferred tax assets and liabilities are recognized on taxable and deductible temporary differences, and on tax loss carry-forwards. Temporary differences are differences between the carrying amount of an asset or liability in the balance sheet and its tax base. • French business taxes include a value added based component: “CVAE” ( Cotisation sur la Valeur Ajoutée des Entreprises ). Given that CVAE is (i) calculated as the amount by which certain revenues exceed certain expenses and (ii) borne primarily by companies that own intellectual property rights on income derived from those rights (royalties, and margin on sales to third parties and to Sanofi entities), it is regarded as meeting the definition of income taxes specified in IAS 12, paragraph 2 (“taxes which are based on taxable profits”). • Deferred tax assets and liabilities are calculated using the tax rate expected to apply in the period when the corresponding temporary differences are expected to reverse, based on tax rates enacted or substantively enacted at the end of the reporting period. • Deferred tax assets are recognized in respect of deductible temporary differences, tax losses available for carry-forward and unused tax credits to the extent that future recovery is regarded as probable. The recoverability of deferred tax assets is assessed on a case-by-case basis, taking into account the profit forecasts contained in Sanofi’s medium-term business plan. • A deferred tax liability is recognized for temporary differences relating to interests in subsidiaries, associates and joint ventures, except in cases where Sanofi is able to control the timing of the reversal of the temporary differences. This applies in particular when Sanofi is able to control dividend policy and it is probable that the temporary differences will not reverse in the foreseeable future. • No deferred tax is recognized on eliminations of intragroup transfers of interests in subsidiaries, associates or joint ventures. • Each tax entity calculates its own net deferred tax position. All net deferred tax asset and liability positions are then aggregated and shown in separate line items on the relevant side of the consolidated balance sheet. Deferred tax assets and liabilities are offset only if (i) Sanofi has a legally enforceable right to offset current tax assets and current tax liabilities, and (ii) the deferred tax assets and deferred tax liabilities relate to income taxes levied by the same taxation authority. • Deferred taxes are not discounted, except implicitly in the case of deferred taxes on assets and liabilities which are already impacted by discounting. In addition, Sanofi has elected not to discount current taxes payable or receivable where the amounts in question are payable or receivable in the long term. • Withholding taxes on intragroup royalties and dividends, and on royalties and dividends collected from third parties, are accounted for as current income taxes. In accounting for business combinations, Sanofi complies with IFRS 3 as regards the recognition of deferred tax assets after the initial accounting period. Consequently, any deferred tax assets recognized by the acquiree after the end of that period in respect of temporary differences or tax loss carry-forwards existing at the acquisition date are recognized in profit or loss. The positions adopted by Sanofi in tax matters are based on its interpretation of tax laws and regulations. Some of those positions may be subject to uncertainty. In such cases, Sanofi assesses the amount of the tax liability on the basis of the following assumptions: that its position will be examined by one or more tax authorities on the basis of all relevant information; that a technical assessment is carried out with reference to legislation, case law, regulations, and established practice; and that each position is assessed individually (or collectively where appropriate), with no offset or aggregation between positions. Those assumptions are assessed on the basis of facts and circumstances existing at the end of the reporting period. When an uncertain tax liability is regarded as probable, it is measured on the basis of Sanofi’s best estimate and recognized as a liability; uncertain tax assets are not recognized. The amount of the liability includes any penalties and late payment interest. The line item Income tax expense includes the effects of tax reassessments and tax disputes, and any penalties and late payment interest arising from such disputes that have the characteristics of income taxes within the meaning of paragraph 2 of IAS 12 (“taxes which are based on taxable profits”). Tax exposures relating to corporate income taxes are presented separately within Non-current income tax liabilities (see Note D.19.4.). No deferred taxation is recognized on temporary differences that are liable to be subject to US global intangible low taxed income (GILTI) provisions. The related tax expense is recognized in the year in which it is declared in the tax return to the extent that it arises from the existence of non-US profits that exceed the theoretical return on investment specified in the GILTI provisions and are taxed at a rate lower than the applicable US tax rate. In accordance with IAS 1 (Presentation of Financial Statements), current income tax assets and liabilities are presented as separate line items in the consolidated balance sheet.
Employee benefit obligations	Employee benefit obligations Sanofi offers retirement benefits to employees and retirees. Such benefits are accounted for in accordance with IAS 19 (Employee Benefits). Benefits are provided in the form of either defined contribution plans or defined benefit plans. In the case of defined contribution plans, the cost is recognized immediately in the period in which it is incurred, and equates to the amount of the contributions paid by Sanofi. For defined benefit plans, Sanofi generally recognizes its obligations to pay pensions and similar benefits to employees as a liability, based on an actuarial estimate of the rights vested or currently vesting in employees and retirees, using the projected unit credit method. Estimates are performed at least once a year, and rely on financial assumptions (such as discount rates) and demographic assumptions (such as life expectancy, retirement age, employee turnover, and the rate of salary increases). Obligations relating to other post-employment benefits (healthcare and life insurance) offered by Sanofi companies to employees are also recognized as a liability based on an actuarial estimate of the rights vested or currently vesting in employees and retirees at the end of the reporting period. Such liabilities are recognized net of the fair value of plan assets. In the case of multi-employer defined benefit plans where plan assets cannot be allocated to each participating employer with sufficient reliability, the plan is accounted for as a defined contribution plan, in accordance with paragraph 34 of IAS 19. The benefit cost for the period consists primarily of current service cost, past service cost, net interest cost, gains or losses arising from plan settlements not specified in the terms of the plan, and actuarial gains or losses arising from plan curtailments. Net interest cost for the period is determined by applying the discount rate specified in IAS 19 to the net liability (i.e. the amount of the obligation, net of plan assets) recognized in respect of defined benefit plans. Past service cost is recognized immediately in profit or loss in the period in which it is incurred, regardless of whether or not the rights have vested at the time of adoption (in the case of a new plan) or of amendment (in the case of an existing plan). Actuarial gains and losses on defined benefit plans (pensions and other post-employment benefits), also referred to as "Remeasurements of the net defined benefit liability (asset)" , arise as a result of changes in financial and demographic assumptions, experience adjustments, and the difference between the actual return and interest cost on plan assets. The impacts of those remeasurements are recognized in Other comprehensive income , net of deferred taxes; they are not subsequently reclassifiable to profit or loss.
Share-based payment	Share-based payment Share-based payment expense is recognized as a component of operating income, in the relevant classification of expense by function. In measuring the expense, the level of attainment of any performance conditions is taken into account. B.24.1. Stock option plans Sanofi has granted a number of equity-settled share-based payment plans (stock option plans) to some of its employees. The terms of those plans may make the award contingent on the attainment of performance criteria for some of the grantees. In accordance with IFRS 2 (Share-Based Payment), services received from employees as consideration for stock options are recognized as an expense in the income statement, with the opposite entry recognized in equity. The expense corresponds to the fair value of the stock option plans, and is charged to income on a straight-line basis over the four-year vesting period of the plan. The fair value of stock option plans is measured at the date of grant using the Black-Scholes valuation model, taking into account the expected life of the options. The resulting expense also takes into account the expected cancellation rate of the options. The expense is adjusted over the vesting period to reflect actual cancellation rates resulting from option-holders ceasing to be employed by Sanofi. B.24.2. Employee share ownership plans Sanofi may offer its employees the opportunity to subscribe to reserved share issues at a discount to the reference market price. Shares awarded to employees under such plans fall within the scope of IFRS 2. Consequently, an expense is recognized at the subscription date, based on the value of the discount offered to employees. B.24.3. Restricted share plans Sanofi may award restricted share plans to certain of its employees. The terms of those plans may make the award contingent on the attainment of performance criteria for some of the grantees. In accordance with IFRS 2, an expense equivalent to the fair value of such plans is recognized in profit or loss on a straight line basis over the vesting period of the plan, with the opposite entry recognized in equity. The vesting period is three The fair value of restricted share plans is based on the quoted market price of Sanofi shares at the date of grant, adjusted for expected dividends during the vesting period; it also takes account of any vesting conditions contingent on stock market performance. Other vesting conditions are taken into account in the estimate of the number of shares awarded during the vesting period; that number is then definitively adjusted based on the actual number of shares awarded on the vesting date.
Earnings per share	Earnings per share Basic earnings per share is calculated using the weighted average number of shares outstanding during the reporting period, adjusted on a time-weighted basis from the acquisition date to reflect the number of own shares held by Sanofi. Diluted earnings per share is calculated on the basis of the weighted average number of ordinary shares, computed using the treasury stock method. This method assumes that (i) all outstanding dilutive options and warrants are exercised, and (ii) Sanofi acquires its own shares at the quoted market price for an amount equivalent to the cash received as consideration for the exercise of the options or warrants, plus the expense arising on unamortized stock options.
Segment information	Segment information In accordance with IFRS 8 (Operating Segments), the segment information reported by Sanofi is prepared on the basis of internal management data provided to the Chief Executive Officer, who is the chief operating decision maker. The performance of those segments is monitored individually using internal reports and common indicators. Disclosures about operating segments required under IFRS 8 are presented in Note D.35. “Segment information” to the consolidated financial statements. Sanofi has three operating segments: Pharmaceuticals, Consumer Healthcare and Vaccines. The Pharmaceuticals segment comprises, for all geographical territories, the commercial operations of the following global franchises: Specialty Care (Dupixent ® , Multiple Sclerosis, Neurology, Other Inflammatory Diseases & Immunology, Rare Diseases, Oncology, and Rare Blood Disorders) and General Medicines (Diabetes, Cardiovascular, and Established Prescription Products), together with research, development and production activities dedicated to the Pharmaceuticals segment. This segment also includes associates whose activities are related to pharmaceuticals. Following the transaction of May 29, 2020, Regeneron is no longer an associate of Sanofi (see Note D.1.). Consequently, the Pharmaceuticals segment no longer includes Sanofi’s equity-accounted share of Regeneron’s profits for all the periods presented. The Consumer Healthcare segment comprises, for all geographical territories, the commercial operations for our Consumer Healthcare products, together with research, development and production activities dedicated to those products. The Vaccines segment comprises, for all geographical territories, the commercial operations of Sanofi Pasteur, together with research, development and production activities dedicated to vaccines. Inter-segment transactions are not material. The costs of Sanofi’s global functions (External Affairs, Finance, Human Resources, Legal Affairs, Information Solutions & Technologies, Sanofi Business Services, etc.) are managed centrally at group-wide level, and are presented within the “Other” category. That category also includes other reconciling items such as retained commitments in respect of divested activities. In 2020, Sanofi adapted its management reporting to reflect the new organizational structure. This resulted in cost reallocations between the Pharmaceuticals, Consumer Healthcare and Vaccines segments and the “Other” category, and product reallocations between Pharmaceuticals and Consumer Healthcare. Information about operating segments for the years ended December 31, 2020, 2019 and 2018 is presented in Note D.35 ., “Segment information”.
Management of capital	Management of capital In order to maintain or adjust the capital structure, Sanofi can adjust the amount of dividends paid to shareholders, repurchase its own shares, issue new shares, or issue securities giving access to its capital. The following objectives are defined under the terms of Sanofi’s share repurchase programs: • the implementation of any stock option plan giving entitlement to purchase shares in the Sanofi parent company; • the allotment or sale of shares to employees under statutory profit sharing schemes and employee savings plans; • the consideration-free allotment of shares (i.e. restricted share plans); • the cancellation of some or all of the repurchased shares; • market-making in the secondary market by an investment services provider under a liquidity contract in compliance with the ethical code recognized by the Autorité des marchés financiers (AMF); • the delivery of shares on the exercise of rights attached to securities giving access to the capital by redemption, conversion, exchange, presentation of a warrant or any other means; • the delivery of shares (in exchange, as payment, or otherwise) in connection with mergers and acquisitions; • the execution by an investment services provider of purchases, sales or transfers by any means, in particular via off-market trading; or • any other purpose that is or may in the future be authorized under the applicable laws and regulations. Sanofi is not subject to any constraints on equity capital imposed by third parties. Total equity includes Equity attributable to equity holders of Sanofi and Equity attributable to non-controlling interests , as shown in the consolidated balance sheet.

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2020
Corporate Information And Statement Of IFRS Compliance [Abstract]
Summary of useful lives of property, plant and equipment	The customary useful lives of property, plant and equipment are as follows: Buildings 15 to 40 years Fixtures 10 to 20 years Machinery and equipment 5 to 15 years Other 3 to 15 years
Disclosure of detailed information about financial instruments	The table below shows the disclosures required under IFRS 7 relating to the measurement principles applied to financial instruments. Note Type of financial instrument Measurement Level in Valuation Method used to determine fair value Valuation Market data Exchange rate Interest D.7. Financial assets measured at fair value (quoted equity instruments) Fair value 1 Market value Quoted market price N/A D.7. Financial assets measured at fair value (quoted debt instruments) Fair value 1 Market value Quoted market price N/A D.7. Financial assets measured at fair value (unquoted equity instruments) Fair value 3 Revenue and/or market-based approach If cost ceases to be a representative measure of fair value, an internal valuation is carried out, based mainly on growth forecasts or by reference to similar transactions contracted with third parties. D.7. Financial assets measured at fair value (contingent consideration receivable) Fair value 3 Revenue-based approach The fair value of contingent consideration receivable is determined by adjusting the contingent consideration at the end of the reporting period using the method described in Note D.7.3. D.7. Financial assets measured at fair value held to meet obligations under post-employment benefit plans Fair value 1 Market value Quoted market price N/A D.7. Financial assets designated at fair value held to meet obligations under deferred compensation plans Fair value 1 Market value Quoted market price N/A D.7. Long-term loans and advances and other non-current receivables Amortized cost N/A N/A The amortized cost of long-term loans and advances and other non-current receivables at the end of the reporting period is not materially different from their fair value. D.13. Investments in mutual funds Fair value 1 Market value Net asset value N/A D.13. Negotiable debt instruments, commercial paper, instant access deposits and term deposits Amortized cost N/A N/A Because these instruments have a maturity of less than 3 months, amortized cost is regarded as an acceptable approximation of fair value as disclosed in the notes to the consolidated financial statements. D.17.1. Debt Amortized cost (a) N/A N/A In the case of debt with a maturity of less than 3 months, amortized cost is regarded as an acceptable approximation of fair value as reported in the notes to the consolidated financial statements. D.20. Forward currency contracts Fair value 2 Present value of future cash flows Mid < 1 year: Mid Money Market > 1 year: Mid Zero Coupon D.20. Interest rate swaps Fair value 2 Revenue-based approach Present value of future cash flows Mid < 1 year: D.20. Cross-currency swaps Fair value 2 Present value of future cash flows Mid < 1 year: D.18. Liabilities related to business combinations and to non-controlling interests (CVRs) Fair value 1 Market value Quoted market price D.18. Liabilities related to business combinations and to non-controlling interests (other than CVRs) Fair value (b) 3 Revenue-based approach Under IAS 32, contingent consideration payable in a business combination is a financial liability. The fair value of such liabilities is determined by adjusting the contingent consideration at the end of the reporting period using the method described in Note B.8.4. (a) In the case of debt designated as a hedged item in a fair value hedging relationship, the carrying amount in the consolidated balance sheet includes changes in fair value attributable to the hedged risk(s). (b) For business combinations completed prior to application of IFRS 3, contingent consideration is recognized when payment becomes probable. See Note B.3.1.

Changes in the scope of conso_2

Changes in the scope of consolidation in 2020 (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations 1 [Abstract]
Summary of purchase price allocation	The provisional purchase price allocation, as presented in the table below, led to the recognition of goodwill of €913 million: (€ million) Fair value at acquisition date Intangible assets other than goodwill 2,534 Other current and non-current assets and liabilities (38) Cash and cash equivalents 186 Net deferred tax position (437) Net assets of Principia 2,245 Goodwill 913 Purchase price 3,158 930 million : (€ million) Fair value at acquisition date Intangible assets other than goodwill 1,549 Other current and non-current assets and liabilities 36 Net deferred tax position (269) Net assets of Synthorx 1,316 Goodwill 930 Purchase price 2,246 The final purchase price allocation resulted in the recognition of goodwill amounting to €2,676 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 8,113 Inventories 145 Cash and cash equivalents 422 Other current and non-current assets and liabilities 16 True North Therapeutics contingent consideration liability (226) Net deferred tax position (1,792) Net assets of Bioverativ 6,678 Goodwill 2,676 Purchase price 9,354 The final purchase price allocation resulted in the recognition of goodwill amounting to €1,360 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 2,409 Cash and cash equivalents 258 Other current and non-current assets and liabilities 131 Net deferred tax position (261) Net assets of Ablynx 2,537 Goodwill 1,360 Purchase price 3,897

Principal changes in the scop_2

Principal changes in the scope of consolidation in 2019 and 2018 (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations 1 [Abstract]
Summary of Changes in Equity Interest Held	Changes in the equity interest held by Sanofi in Regeneron during 2019 and 2018 are set forth below: (€ million) 2019 2018 Carrying amount (a) 3,342 3,055 Equity interest 21.2 % 21.7 % Acquisitions of shares — — Disposals of shares (b) 33 24 (a) See Note D.6. ® , Dupixent ® and REGN3500 (SAR440340) (see Note C.1.).
Summary of purchase price allocation	The provisional purchase price allocation, as presented in the table below, led to the recognition of goodwill of €913 million: (€ million) Fair value at acquisition date Intangible assets other than goodwill 2,534 Other current and non-current assets and liabilities (38) Cash and cash equivalents 186 Net deferred tax position (437) Net assets of Principia 2,245 Goodwill 913 Purchase price 3,158 930 million : (€ million) Fair value at acquisition date Intangible assets other than goodwill 1,549 Other current and non-current assets and liabilities 36 Net deferred tax position (269) Net assets of Synthorx 1,316 Goodwill 930 Purchase price 2,246 The final purchase price allocation resulted in the recognition of goodwill amounting to €2,676 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 8,113 Inventories 145 Cash and cash equivalents 422 Other current and non-current assets and liabilities 16 True North Therapeutics contingent consideration liability (226) Net deferred tax position (1,792) Net assets of Bioverativ 6,678 Goodwill 2,676 Purchase price 9,354 The final purchase price allocation resulted in the recognition of goodwill amounting to €1,360 million, as indicated below: (€ million) Fair value at acquisition date Other intangible assets 2,409 Cash and cash equivalents 258 Other current and non-current assets and liabilities 131 Net deferred tax position (261) Net assets of Ablynx 2,537 Goodwill 1,360 Purchase price 3,897
Summary of Assets and Liabilities Divested	An analysis of the assets and liabilities divested is set forth below: (€ million) September 30, 2018 Assets Property, plant and equipment 120 Goodwill 913 Other intangible assets 75 Other non-current assets 1 Deferred tax assets 83 Inventories 129 Accounts receivable 107 Other current assets 40 Cash and cash equivalents 122 Total assets of the divested European Generics business 1,590 Liabilities Non-current provisions and other non-current liabilities 27 Deferred tax liabilities 14 Accounts payable 91 Other current liabilities 216 Short-term debt and current portion of long-term debt 46 Total liabilities of the divested European Generics business 394

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, plant and equipment [abstract]
Schedule of Property, Plant and Equipment (Including Assets Held Under Finance Leases)	Property, plant and equipment owned by Sanofi (including property, plant and equipment acquired under finance leases for 2018, prior to the application of IFRS 16) is comprised of the following items: (€ million) Land Buildings Machinery Fixtures, Property, plant Total Gross value at January 1, 2018 318 6,768 10,145 2,450 2,297 21,978 Changes in scope of consolidation — 6 11 4 1 22 Acquisitions and other increases — 22 48 71 1,318 1,459 Disposals and other decreases (23) (227) (272) (127) (20) (669) Currency translation differences — 57 26 17 11 111 Transfers (a) (12) 257 510 164 (1,123) (204) Gross value at December 31, 2018 283 6,883 10,468 2,579 2,484 22,697 Acquisitions and other increases — 10 50 56 1,145 1,261 Disposals and other decreases (3) (42) (148) (114) (12) (319) Currency translation differences 6 80 64 17 33 200 Transfers (a) (31) 351 619 49 (1,259) (271) Gross value at December 31, 2019 255 7,282 11,053 2,587 2,391 23,568 Changes in scope of consolidation — 6 3 1 — 10 Acquisitions and other increases — 16 40 46 1,208 1,310 Disposals and other decreases (11) (173) (177) (123) (3) (487) Currency translation differences (13) (264) (276) (67) (91) (711) Transfers (a) 5 (39) 484 80 (1,051) (521) Gross value at December 31, 2020 236 6,828 11,127 2,524 2,454 23,169 Accumulated depreciation & impairment at January 1, 2018 (20) (3,612) (6,885) (1,804) (78) (12,399) Depreciation expense — (351) (595) (191) — (1,137) Impairment losses, net of reversals (8) (24) (40) (11) (12) (95) Disposals and other decreases 8 170 235 110 3 526 Currency translation differences — (29) (15) (14) — (58) Transfers (a) 1 50 70 (4) — 117 Accumulated depreciation & impairment at December 31, 2018 (19) (3,796) (7,230) (1,914) (87) (13,046) Depreciation expense — (357) (586) (194) — (1,137) Impairment losses, net of reversals (4) (33) (4) (2) (55) (98) Disposals and other decreases 2 54 140 106 11 313 Currency translation differences — (40) (40) (12) — (92) Transfers (a) 10 107 60 32 — 209 Accumulated depreciation & impairment at December 31, 2019 (11) (4,065) (7,660) (1,984) (131) (13,851) Depreciation expense — (356) (605) (182) — (1,143) Impairment losses, net of reversals — (24) (12) (7) — (43) Disposals and other decreases 1 168 166 117 8 460 Currency translation differences — 127 169 49 — 345 Transfers (a) — 252 150 26 — 428 Accumulated depreciation & impairment at December 31, 2020 (10) (3,898) (7,792) (1,981) (123) (13,804) Carrying amount at December 31, 2018 264 3,087 3,238 665 2,397 9,651 Carrying amount at December 31, 2019 244 3,217 3,393 603 2,260 9,717 Carrying amount at December 31, 2020 226 2,930 3,335 543 2,331 9,365 (a) This line mainly comprises property, plant and equipment in process brought into service during the period, but also includes the effect of the reclassification of assets to Assets held for sale or exchange , and for 2019 the reclassification of assets held under finance leases to Right-of-use assets on first-time application of IFRS 16.
Summary of Acquisitions and Capitalized Interest by Operating Segment	The table below sets forth acquisitions and capitalized interest by operating segment for the years ended December 31, 2020, 2019 and 2018: (€ million) 2020 2019 2018 Acquisitions 1,310 1,261 1,459 Pharmaceuticals 831 846 1,014 Industrial facilities 634 682 769 Research sites 152 87 14 Other 45 77 231 Vaccines 384 405 440 Consumer Healthcare 95 10 5 Capitalized interest 11 14 21
Summary of Off Balance Sheet Commitments Relating to Property, Plant and Equipment	Off balance sheet commitments relating to property, plant and equipment as of December 31, 2020, 2019 and 2018 are set forth below: (€ million) 2020 2019 2018 Firm orders of property, plant and equipment 708 398 535 Property, plant and equipment pledged as security for liabilities — 107 123
Summary of Impairment Losses Recognised in Property, Plant and Equipment	Impairment tests of property, plant and equipment conducted using the method described in Note B.6. resulted in the recognition of the following net impairment losses in each of the last three financial periods: (€ million) 2020 2019 2018 Net impairment losses on property, plant and equipment 43 98 94
Schedule of Amounts for Items of Property, Plant and Equipment Held under Finance Leases	The table below shows amounts for items of property, plant and equipment held under finance leases: (€ million) 2018 Buildings 73 Other property, plant and equipment 14 Total gross value 87 Accumulated depreciation and impairment (64) Carrying amount 23
Summary of Future Minimum Lease Payments Due Under Finance Lease	Future minimum lease payments due under finance leases are shown in the table below: (€ million) 2018 Future minimum lease payments due under finance leases 25 of which interest 3
Disclosure of Quantitative Information About Right-Of-Use Assets	Right-of-use assets relating to property, plant and equipment leased by Sanofi are analyzed in the table below: (€ million) Right-of-use assets Gross value at January 1, 2019 1,439 Acquisitions and other increases 157 Disposals and other decreases (31) Currency translation differences 18 Gross value at December 31, 2019 1,583 Changes in scope of consolidation 15 Acquisitions and other increases 340 Disposals and other decreases (121) Currency translation differences (85) Transfers (a) (21) Gross value at December 31, 2020 1,711 Accumulated depreciation & impairment at January 1, 2019 (8) Depreciation and amortization expense (b) (282) Disposals and other decreases 7 Accumulated depreciation & impairment at December 31, 2019 (283) Depreciation and amortization expense (b) (299) Disposals and other decreases 44 Currency translation differences 22 Transfers (a) 3 Accumulated depreciation & impairment at December 31, 2020 (513) Carrying amount at January 1, 2019 (c) 1,431 Carrying amount at December 31, 2019 1,300 Carrying amount at December 31, 2020 1,198 (a) This line also includes the effect of the reclassification of assets to Assets held for sale or exchange as of December 31, 2020. (b) Impairment losses against right of use assets amounted to €31 million as of December 31, 2020. and were immaterial as of December 31, 2019. (c) Sanofi elected the simplified retrospective method for first-time application of IFRS 16 (Leases), which involved recognizing a right-of-use asset equal to the lease liability, adjusted by the amount of any prepaid or accrued lease payments; impacts of the adoption of IFRS 16 on the balance sheet primarily included the recognition of right-of-use assets of €1,431 million, the recognition of current and non-current lease liabilities of €1,346 million, and an increase in provisions and other current and non-current liabilities of €73 million.

Goodwill and other intangible_2

Goodwill and other intangible assets (Tables)	12 Months Ended
	Dec. 31, 2020
Intangible Assets [Abstract]
Schedule of Movements in Goodwill	Movements in goodwill comprise: (€ million) Goodwill Balance at January 1, 2018 40,264 Acquisitions during the period 4,039 Other movements during the period (a) (1,006) Currency translation differences 938 Balance at December 31, 2018 44,235 Acquisitions during the period — Other movements during the period (a) (244) Currency translation differences 528 Balance at December 31, 2019 44,519 Acquisitions during the period 1,843 Other movements during the period (a) (75) Currency translation differences (1,923) Balance at December 31, 2020 44,364 (a) This line includes the amount of goodwill allocated to divested operations in accordance with paragraph 86 of IAS 36. In 2018, it mainly comprises the goodwill allocated to the European Generics business when it was divested (see Note D.2.2.).
Schedule of Movements in Other Intangible Assets	Movements in other intangible assets comprise: (€ million) Acquired R&D Products, Software Total other Gross value at January 1, 2018 3,679 53,638 1,368 58,685 Changes in scope of consolidation 3,632 6,889 2 10,523 Acquisitions and other increases 367 16 251 634 Disposals and other decreases (44) (920) (75) (1,039) Currency translation differences 218 1,757 10 1,985 Transfers (a) (430) 420 3 (7) Gross value at December 31, 2018 7,422 61,800 1,559 70,781 Acquisitions and other increases 272 19 184 475 Disposals and other decreases (236) (569) (50) (855) Currency translation differences 86 889 10 985 Transfers (a) (1,814) 1,814 (5) (5) Gross value at December 31, 2019 5,730 63,953 1,698 71,381 Changes in scope of consolidation 3,951 132 — 4,083 Acquisitions and other increases 654 58 137 849 Disposals and other decreases (44) (243) (46) (333) Currency translation differences (593) (2,926) (39) (3,558) Transfers (a) (98) 100 (2) — Gross value at December 31, 2020 9,600 61,074 1,748 72,422 Accumulated amortization & impairment at January 1, 2018 (2,204) (42,476) (925) (45,605) Amortization expense — (2,188) (115) (2,303) Impairment losses, net of reversals (b) (456) (264) (10) (730) Disposals and other decreases 36 840 68 944 Currency translation differences (54) (1,146) (6) (1,206) Transfers (a) — 6 2 8 Accumulated amortization & impairment at December 31, 2018 (2,678) (45,228) (986) (48,892) Amortization expense — (2,167) (134) (2,301) Impairment losses, net of reversals (b) (847) (2,757) (23) (3,627) Disposals and other decreases 158 488 51 697 Currency translation differences (31) (648) (8) (687) Transfers (a) 2 (2) 1 1 Accumulated amortization & impairment at December 31, 2019 (3,396) (50,314) (1,099) (54,809) Amortization expense — (1,707) (125) (1,832) Impairment losses, net of reversals (b) (328) (2) — (330) Disposals and other decreases 44 232 45 321 Currency translation differences 158 2,460 31 2,649 Transfers (a) 14 (14) — — Accumulated amortization & impairment at December 31, 2020 (3,508) (49,345) (1,148) (54,001) Carrying amount at December 31, 2018 4,744 16,572 573 21,889 Carrying amount at December 31, 2019 2,334 13,639 599 16,572 Carrying amount at December 31, 2020 6,092 11,729 600 18,421 (a) The “Transfers” line mainly relates to acquired R&D that came into commercial use during the period and is being amortized from the date of marketing approval. (b) See Note D.5.
Detailed Information for Principal Marketed Products	The table below provides information about the principal "marketed products", which were recognized in connection with business combinations and represented 91% of the carrying amount of that item as of December 31, 2020: (€ million) Gross Accumulated Carrying amount at December 31, 2020 Amortization period (years) (a) Residual amortization period (years) (b) Carrying amount at December 31, 2019 Carrying amount at December 31, 2018 Genzyme 9,823 (8,338) 1,485 10 3 2,095 2,988 Boehringer Ingelheim 3,687 (1,198) 2,489 16 14 2,699 3,237 Aventis 32,474 (32,364) 110 9 7 219 409 Chattem 1,192 (590) 602 23 13 711 748 Protein Sciences 751 (197) 554 13 10 667 715 Ablynx 2,279 (418) 1,861 13 11 2,029 376 Bioverativ 6,516 (3,276) 3,240 13 11 3,788 6,385 Total: principal marketed products 56,722 (46,381) 10,341 12,208 14,858 (a) Weighted averages. The amortization periods for these products vary between 1 and 25 years. (b) Weighted averages.
Amortization of Softwares Recognized in Income Statement	An analysis of amortization of software is shown in the table below: (€ million) 2020 2019 2018 Cost of sales 19 11 21 Research and development expenses 2 3 4 Selling and general expenses 100 114 87 Other operating expenses 4 6 3 Total 125 134 115

Impairment of intangible asse_2

Impairment of intangible assets and property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Impairment Of Assets [Abstract]
Schedule of Allocation of Goodwill	The allocation of goodwill as of December 31, 2020 is shown below: (€ million) Pharmaceuticals Consumer Healthcare Vaccines Total Goodwill 36,682 6,425 1,257 44,364
Summary of Net Impairment Losses of Other Intangible Assets	In 2020, 2019 and 2018, impairment testing of other intangible assets (excluding software) resulted in the recognition of net impairment losses as shown below: (€ million) 2020 2019 2018 Impairment of other intangible assets (excluding software) 330 3,604 720 Marketed products 2 2,757 264 Pharmaceuticals (a) 2 2,405 258 Vaccines — — 6 CHC (b) — 352 — Research and development projects (c) 328 847 454 Other (d) — — 2 (a) Impairment tests conducted on other intangible assets as of December 31, 2019 led to (i) the recognition of an impairment loss of €2,236 million on the product Eloctate ® (as part of the broader Eloctate ® franchise) and (ii) an impairment loss of €163 million on the marketed product Lemtrada ® , compared with €183 million as of December 31, 2018. (b) Impairment tests conducted on other intangible assets as of December 31, 2019 led to the recognition of an impairment loss of €352 million on assets related to Zantac ® . (c) For 2020, this line mainly comprises impairment losses taken against R&D programs within the Specialty Care GBU, and the discontinuation of certain R&D programs and collaboration agreements in Diabetes. For 2019, it relates mainly to (i) the allocation of the impairment loss recognized for the Eloctate ® franchise to the BIVV001 project (see (a) above), and (ii) the termination of the development program for sotagliflozin (€275 million). For 2018, this line relates mainly to intangible assets of Ablynx and to other R&D intellectual property assets, including the MyoKardia and efpeglenatide programs in Diabetes. (d) Not included within the line item Impairment of intangible assets in the consolidated income statements (see Note B.4.).

Investments accounted for usi_2

Investments accounted for using the equity method (Tables)	12 Months Ended
	Dec. 31, 2020
Interests In Other Entities [Abstract]
Summary of Investments in Associates and Joint Ventures	(€ million) % interest 2020 2019 2018 Regeneron Pharmaceuticals, Inc. (a) — — 3,342 3,055 Onduo LLC (b) 19.9 — — 108 Infraserv GmbH & Co. Höchst KG (c) 31.2 72 70 73 Entities and companies managed by Bristol-Myers Squibb (d) 100.0 — 37 40 Other investments — 129 142 126 Total 201 3,591 3,402 (a) Following the transaction of May 29, 2020 as described in Note D.1. above, which resulted in the divestment of 22.8 million Regeneron shares, Sanofi no longer exercises significant influence over Regeneron. As of that date, Sanofi retained 0.4 million Regeneron shares, classified in the “Equity instruments at fair value through other comprehensive income” category (see Note D.7.1.). As of December 31, 2020, Sanofi held 279,766 Regeneron shares. (b) As a result of the restructuring of Onduo LLC, finalized November 11, 2019, Sanofi lost significant influence over that entity on that date; this did not have a material impact on profit or loss in the year ended December 31, 2019. As of that date, Sanofi held a 19.9% equity interest in Onduo. As of December 31, 2020, Sanofi still held a 19.9% equity interest in Onduo. (c) Joint venture. (d) On February 28, 2020, Sanofi acquired from Bristol-Myers Squibb the remaining 50.1% equity interest not yet held by Sanofi in the three partnerships that organize the commercialization of Plavix ® in the United States and Puerto Rico, for a total consideration of $12 million. The acquisition was accounted for in accordance with IFRS 3 (Business Combinations).
Summary of Share of Profit or Loss and Other Comprehensive Income of Associates and Joint Ventures	The table below shows Sanofi’s overall share of (i) profit or loss and (ii) other comprehensive income from investments accounted for using the equity method, showing the split between associates and joint ventures in accordance with IFRS 12 (the amounts for each individual associate or joint venture are not material): 2020 2019 2018 (€ million) Joint ventures Associates Joint ventures Associates Joint ventures Associates Share of profit/(loss) from investments accounted for using the equity method 4 355 (a) 15 240 17 482 Share of other comprehensive income from investments accounted for using the equity method 8 (311) (7) 90 (7) 105 Total 12 44 8 330 10 587 (a) Includes €343 million for Sanofi's share of the net income of Regeneron up to and including May 29, 2020 (see Note D.1.)
Summary of Principal Transactions and Balances with Related Parties	The principal transactions and balances with related parties are summarized below: (€ million) 2020 2019 2018 Sales 75 24 35 Royalties and other income (a) 97 270 116 Accounts receivable and other receivables 50 151 89 Purchases and other expenses (including research expenses) (a) 747 1,334 1,143 Accounts payable and other payables 15 342 544 (a) For 2020, these amounts include transactions between Sanofi and Regeneron for the period from January 1 through May 29, 2020. The table above does not include the repurchase by Regeneron of its own shares from Sanofi (see Note D.1.).
Summary of Financial Statements of Regeneron, After Adjustments to Comply With IFRS But Before Fair Value Remeasurements	Key items from the 2018 and 2019 consolidated financial statements of Regeneron, after adjustments to comply with IFRS (including those required to align on elective accounting treatments adopted by Sanofi) but before fair value remeasurements, are set forth below: (€ million) 2019 2018 Net sales and other revenues 7,023 5,680 Net income 1,882 2,476 Other comprehensive income for the period, net of taxes 113 (33) Comprehensive income 1,995 2,443 (€ million) December 31, 2019 December 31, 2018 Current assets 6,858 5,621 Non-current assets 6,627 4,731 Total assets 13,485 10,352 Current liabilities 1,870 1,258 Non-current liabilities 925 772 Total liabilities 2,795 2,030 Consolidated shareholders’ equity of Regeneron 10,690 8,322
Summary of Reconciliation to Carrying Amount of Investment	The table below shows a reconciliation to the carrying amount of the investment: (€ million) December 31, 2019 December 31, 2018 % interest 21 % 22 % Share of equity attributable to Sanofi 2,263 1,806 Goodwill 839 858 Fair value remeasurements of assets and liabilities at the acquisition date 811 873 Other items (a) (571) (482) Carrying amount of the investment in Regeneron 3,342 3,055 (a) Mainly comprises the difference arising from Sanofi’s share of the accumulated profits and losses and other changes in the net assets of Regeneron for the periods prior to first-time application of the equity method, and thereafter (i) Sanofi’s share of the stock option expense recognized against equity in the books of Regeneron, and of the deferred taxes recognized against equity in respect of that expense in accordance with IAS 12 paragraph 68.C. and (ii) the effects of the elimination of internal profits between Sanofi and Regeneron.
Summary of Market Value of Sanofi's Investment in Regeneron Based on Quoted Stock Market Price Per Share	The market value of Sanofi’s investment in Regeneron as of December 31, 2019 and 2018, based on the quoted stock market price per share in US dollars, is shown below: 2019 2018 Quoted stock market price per share ($) 375.48 373.50 Market value of investment in Regeneron ($ million) 8,767 8,835 Market value of investment in Regeneron (€ million) 7,820 7,702

Other non-current assets (Table

Other non-current assets (Tables)	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Summary of Other Non-current Assets	Other non-current assets comprise: (€ million) 2020 2019 2018 Equity instruments at fair value through other comprehensive income (D.7.1.) 588 380 1,037 Debt instruments at fair value through other comprehensive income (D.7.2.) 426 403 359 Other financial assets at fair value through profit or loss (D.7.3.) 890 892 733 Pre-funded pension obligations (Note D.19.1.) 177 155 77 Long-term prepaid expenses 92 115 126 Long-term loans and advances and other non-current receivables 537 521 464 Derivative financial instruments (Note D.20.) 24 37 19 Total 2,734 2,503 2,815

Assets held for sale or excha_2

Assets held for sale or exchange and liabilities related to assets held for sale or exchange (Tables)	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Summary of Assets Held for Sale or Exchange, and Liabilities Related to Assets Held for Sale or Exchange	Assets held for sale or exchange, and liabilities related to assets held for sale or exchange, comprise: (€ million) December 31, 2020 December 31, 2019 December 31, 2018 Assets held for sale or exchange 83 325 68 Liabilities related to assets held for sale or exchange 32 6 —

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Schedule of Inventories	Inventories comprise the following: 2020 2019 2018 (€ million) Gross Allowances Carrying Gross Allowances Carrying Gross Allowances Carrying Raw materials 1,051 (76) 975 1,163 (76) 1,087 1,099 (83) 1,016 Work in process 5,398 (542) 4,856 5,104 (582) 4,522 4,637 (549) 4,088 Finished goods 2,739 (218) 2,521 2,629 (244) 2,385 2,533 (160) 2,373 Total 9,188 (836) 8,352 8,896 (902) 7,994 8,269 (792) 7,477

Accounts receivable (Tables)

Accounts receivable (Tables)	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Summary of Accounts Receivable	Accounts receivable break down as follows: (€ million) December 31, 2020 December 31, 2019 December 31, 2018 Gross value 7,633 8,090 7,430 Allowances (142) (153) (170) Carrying amount 7,491 7,937 7,260
Summary of Gross Value of Overdue Receivables	Overdue accounts Overdue by Overdue by Overdue by Overdue by Overdue by (€ million) gross value <1 month 1 to 3 months 3 to 6 months 6 to 12 months > 12 months December 31, 2020 549 271 97 52 34 95 December 31, 2019 642 269 171 61 36 105 December 31, 2018 547 257 172 36 21 61

Other current assets (Tables)

Other current assets (Tables)	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Schedule of Other Current Assets	An analysis of Other current assets is set forth below: (€ million) 2020 2019 2018 Tax receivables, other than corporate income taxes 687 603 564 Other receivables 567 735 627 Prepaid expenses 525 493 469 Interest rate derivatives measured at fair value (see Note D.20.) — 4 30 Currency derivatives measured at fair value (see Note D.20.) 58 184 134 Other current financial assets (a) 900 426 199 Total 2,737 2,445 2,023

Financial assets and liabilit_2

Financial assets and liabilities measured at fair value (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Measurement [Abstract]
Summary of Assets and Liabilities Measured at Fair Value	The table below shows the balance sheet amounts of assets and liabilities measured at fair value. 2020 2019 2018 Level in the fair value hierarchy Level in the fair value Level in the fair value (€ million) Note Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Financial assets measured at fair value Quoted equity investments D.7.1. 439 — — 114 — — 859 — — Unquoted equity investments D.7.1. — — 149 — — 290 — — 197 Quoted debt securities D.7.2. 426 — — 403 — — 359 — — Unquoted debt securities not meeting the definition of equity instruments D.7.3. — — 63 — — 52 — — 61 Contingent consideration relating to divestments D.7.3. — — 483 — — 492 — — 373 Financial assets held to meet obligations under deferred compensation plans D.7.3. and D.11. 454 — — 442 — — 364 — — Non-current derivatives D.7. — 24 — — 37 — — 19 — Current derivatives D.11. — 58 — — 188 — — 164 — Mutual fund investments D.13. 8,703 — — 5,304 — — 3,189 — — Total financial assets measured at fair value 10,022 82 695 6,263 225 834 4,771 183 631 Financial liabilities measured at fair value CVRs issued in connection with the acquisition of Genzyme D.18. — — — — — — 99 — — Bayer contingent purchase consideration arising from the acquisition of Genzyme D.18. — — 104 — — 156 — — 472 MSD contingent consideration (European vaccines business) D.18. — — 312 — — 385 — — 410 Other contingent consideration arising from business combinations D.18. — — 189 — — 259 — — 301 Liabilities related to non-controlling interests D.18. — — — — — — — — 22 Non-current derivatives D.19. — 92 — — 10 — — 7 — Current derivatives D.19.5 — 205 — — 89 — — 90 — Total financial liabilities measured at fair value — 297 605 — 99 800 99 97 1,205

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Summary of Cash and Cash Equivalents	(€ million) 2020 2019 2018 Cash 1,144 701 661 Cash equivalents (a) 12,771 8,726 6,264 Cash and cash equivalents 13,915 9,427 6,925 (a) As of December 31, 2020, cash equivalents mainly comprised the following: (i) €8,703 million invested in euro and US dollar denominated money-market mutual funds (December 31, 2019: €5,304 million; December 31, 2018: €3,189 million); (ii) €3,259 million of term deposits (December 31, 2019: €2,211 million; December 31, 2018: €2,014 million) and (iii) €74 million in commercial paper (December 31, 2019: €446 million; December 31, 2018: €357 million). Cash equivalents also include €425 million held by captive insurance and reinsurance companies in accordance with insurance regulations (December 31, 2019: €456 million; December 31, 2018: €505 million).

Net deferred tax position (Tabl

Net deferred tax position (Tables)	12 Months Ended
	Dec. 31, 2020
Income Taxes [Abstract]
Summary of Net Deferred Tax Position	An analysis of the net deferred tax position is set forth below: (€ million) 2020 2019 2018 Deferred taxes on: Consolidation adjustments (intragroup margin in inventory) 1,142 1,270 1,195 Provision for pensions and other employee benefits 1,213 1,327 1,166 Remeasurement of other acquired intangible assets (3,083) (a) (2,656) (3,740) Recognition of acquired property, plant and equipment at fair value (27) (33) (31) Equity interests in subsidiaries and investments in other entities (b) (522) (421) (437) Tax losses available for carry-forward 1,327 1,323 1,341 Stock options and other share-based payments 88 142 110 Accrued expenses and provisions deductible at the time of payment (c) 1,399 1,405 1,394 Other (d) 905 783 201 Net deferred tax asset/(liability) 2,442 3,140 1,199 (a) As of December 31, 2020, includes remeasurements of the acquired intangible assets of Bioverativ ( €1,021 million), Principia (€547 million), Genzyme (€367 million) and Synthorx (€315 million). (b) In some countries, Sanofi is liable for withholding taxes and other tax charges when dividends are distributed. Consequently, Sanofi recognizes a deferred tax liability on the reserves of French and foreign subsidiaries (approximately €47.8 billion) which it regards as likely to be distributed in the foreseeable future. In determining the amount of the deferred tax liability as of December 31, 2020, Sanofi took into account changes in the ownership structure of certain subsidiaries, and the effects of changes in the taxation of dividends in France following the ruling of the Court of Justice of the European Union in the Steria case and the resulting amendments to the 2015 Finance Act. (c) Includes deferred tax assets related to restructuring provisions, amounting to €307 million as of December 31, 2020, €259 million as of December 31, 2019, and €218 million as of December 31, 2018. (d) The 2019 movement in the "Other" line mainly comprises the recognition of a deferred tax asset on an internal transfer of intangible assets.
Summary of Tax Losses Available for Carry-forward	The table below shows when tax losses available for carry-forward are due to expire: (€ million) Tax losses available for carry-forward (a) 2021 53 2022 37 2023 36 2024 10 2025 38 2026 and later 6,341 Total as of December 31, 2020 6,515 Total as of December 31, 2019 6,401 Total as of December 31, 2018 6,100 (a) Excluding tax loss carry-forwards on asset disposals. Such carry-forwards amounted to €6 million as of December 31, 2020, and €1 million as of December 31, 2019 and December 31, 2018.

Consolidated shareholders_ eq_2

Consolidated shareholders’ equity (Tables)	12 Months Ended
	Dec. 31, 2020
Share Capital, Reserves And Other Equity Interest [Abstract]
Summary of Treasury Shares Held	Treasury shares held by Sanofi are as follows: Number of shares (million) % of share capital for the period December 31, 2020 8.28 0.658 % December 31, 2019 0.02 0.002 % December 31, 2018 1.94 0.156 % January 1, 2018 0.17 0.014 %
Summary of Movements Share Capital	Movements in the share capital of the Sanofi parent company over the last three years are set forth below: Date Transaction Number of shares December 31, 2017 1,254,019,904 During 2018 Capital increase by exercise of stock subscription options (a) 1,168,808 During 2018 Capital increase by issuance of restricted shares (b) 2,152,183 Board meeting of April 26, 2018 Reduction in share capital by cancellation of treasury shares (7,239,803) Board meeting of July 27, 2018 Capital increase reserved for employees 2,401,184 Board meeting of December 18, 2018 Reduction in share capital by cancellation of treasury shares (5,106,804) December 31, 2018 1,247,395,472 During 2019 Capital increase by exercise of stock subscription options (a) 2,745,853 During 2019 Capital increase by issuance of restricted shares (b) 3,704,786 December 31, 2019 1,253,846,111 During 2020 Capital increase by exercise of stock subscription options (a) 868,655 During 2020 Capital increase by issuance of restricted shares (b) 1,666,256 Board meeting of July 28, 2020 Capital increase reserved for employees 2,590,716 December 31, 2020 1,258,971,738 (a) Shares issued on exercise of Sanofi stock subscription options. (b) Shares vesting under restricted share plans and issued in the period.
Principal Characteristics of Restricted Share Plans	Restricted share plans are accounted for in accordance with the policies described in Note B.24.3. The principal characteristics of those plans are as follows: 2020 2019 2018 Type of plan Performance Performance Performance Performance Performance Date of Board meeting approving the plan April 28, 2020 October 28, 2020 April 30, 2019 July 30, 2018 May 2, 2018 Service period 3 years 3 years 3 years 3 years 3 years Total number of shares awarded in 2018 and 2019 3,797,582 141,669 4,390,216 Fair value per share awarded (€) (a) 67.90 64.35 56.59 Total number of shares awarded in 2020 3,340,501 73,027 Of which with no market condition 2,536,893 — Fair value per share awarded (€) (a) 82.36 — Of which with market condition 803,608 73,027 Fair value per share awarded (€) (b) 76.11 63.18 Fair value of plan at the date of grant (€ million) 270 5 258 9 248 (a) Market price of Sanofi shares at the date of grant, adjusted for dividends expected during the vesting period. (b) Weighting between (i) fair value determined using the Monte Carlo model and (ii) market price of Sanofi shares at the date of grant, adjusted for dividends expected during the vesting period.
Summary of Number of Restricted Shares Not Yet Fully Vested	The total expense recognized for all restricted share plans, and the number of restricted shares not yet fully vested, are shown in the table below: 2020 2019 2018 Total expense for restricted share plans (€ million) 222 247 248 Number of shares not yet fully vested 10,546,612 10,908,503 13,576,464 Under 2020 plans 3,284,558 — — Under 2019 plans 3,375,717 3,662,806 — Under 2018 plans 3,886,337 4,117,795 4,406,593 Under 2017 plans — 3,127,902 3,314,391 Under 2016 plans — — 3,690,226 Under 2015 plans — — 2,165,254
Summary of Characteristics of Employee Share Ownership Plans Awarded	The characteristics of the employee share ownership plans awarded in the form of a capital increase reserved for employees in 2020 and 2018 are summarized in the table below; there were no capital increases reserved for employees in 2019. 2020 2018 Date of Board meeting approving the plan February 5, 2020 March 6, 2018 Subscription price (€) (a) 70.67 52.66 Subscription period June 8-26, 2020 June 11-29, 2018 Number of shares subscribed 2,467,101 2,298,783 Number of shares issued immediately as employer’s contribution 123,615 102,401 (a) Subscription price representing 80% of the average of the opening quoted market prices of Sanofi shares during the 20 trading days preceding June 2, 2020 and June 9, 2018, respectively.
Summary of Expenses	The table below sets forth the expense recognized for each plan: (€ million) 2020 2018 Expense recognized 52 32 of which employer’s contribution 11 7
Summary of Repurchases program	The following repurchases have been made under those programs: (in number of shares and € million) Year of authorization 2020 2019 2018 Number of shares Value Number of shares Value Number of shares Value 2020 program 5,685,426 461 — — — — 2019 program 3,982,939 361 — — — — 2018 program — — 147,793 12 6,884,792 501 2017 program — — — — 8,489,873 602
Summary of Currency Translation Differences	Currency translation differences comprise the following: (€ million) 2020 2019 2018 Attributable to equity holders of Sanofi (3,386) 632 (167) Attributable to non-controlling interests (55) (36) (36) Total (3,441) 596 (203)
Summary of Movements within Other Comprehensive Income	Movements within other comprehensive income are shown below: (€ million) 2020 2019 2018 Actuarial gains/(losses): • Actuarial gains/(losses) excluding investments accounted for using the equity method (see Note D.19.1.) (267) (377) 201 • Actuarial gains/(losses) of investments accounted for using the equity method, net of taxes (1) (5) — • Tax effects 45 161 (69) Equity instruments included in financial assets and financial liabilities: • Change in fair value (excluding investments accounted for using the equity method) 358 30 (529) • Change in fair value (investments accounted for using the equity method, net of taxes) (14) 80 (8) • Equity risk hedging instruments designated as fair value hedges (24) (4) — • Tax effects (85) (48) 100 Items not subsequently reclassifiable to profit or loss 12 (163) (305) Debt instruments included in financial assets: • Change in fair value (excluding investments accounted for using the equity method) (a) 15 28 (4) • Change in fair value (investments accounted for using the equity method, net of taxes) — — — • Tax effects (3) (5) — Cash flow hedges: • Change in fair value (excluding investments accounted for using the equity method) (b) 4 (13) 3 • Change in fair value (investments accounted for using the equity method, net of taxes) — — — ▪ Tax effects (2) 4 (1) Change in currency translation differences: • Currency translation differences on foreign subsidiaries (excluding investments accounted for using the equity method) (b) (3,872) 850 1,273 • Currency translation differences (investments accounted for using the equity method) (b) 32 64 106 • Currency translation differences related to the investment in Regeneron and reclassified to profit or loss (c) (318) — — • Hedges of net investments in foreign operations (b) 180 (163) (185) • Tax effects (c) (58) 48 72 Items subsequently reclassifiable to profit or loss (4,022) 813 1,264 (a) Amounts reclassified to profit or loss: €5 million in 2020, and immaterial in 2019 and 2018. (b) Amounts reclassified to profit or loss: €1 million in 2020, €27 million in 2019 and €(7) million in 2018. (c) Relates to the translation reserve arising on the investment in Regeneron, which was reclassified to profit or loss in accordance with IAS 21 (The Effects of Changes in Foreign Exchange Rates), of which €2 million (net of tax) related to hedges of net investments in foreign operations.
Summary of Stock Option Plans Awarded and Measurement of Stock Option Plans	Stock options granted by the Board of Directors in 2019 and 2018 are summarized below, with the assumptions used to determine their fair value: 2019 2018 Date of Board meeting approving the plan April 30, 2019 May 2, 2018 Total number of options granted 220,000 220,000 Exercise price (€) 76.71 65.84 Vesting period 4 years 4 years Plan expiry date April 30, 2029 May 2, 2028 Fair value of the plan (€ million) 2 1 Fair value per option granted (€) 7.80 6.32 Assumptions used to determine fair value Dividend yield 4.31 % 4.87 % Volatility of Sanofi shares, computed on a historical basis 22.48 % 23.10 % Risk-free interest rate 0.15 % 0.36 % Plan maturity 8 years 7 years
Disclosure of Stock Subscription Option Plan Outstanding and Option Exercised	The table shows all Sanofi stock subscription option plans still outstanding or under which options were exercised in the year ended December 31, 2020: Source Date of grant Number of Start date of Expiry date Exercise Number of options outstanding as of 12/31/2020 Sanofi-aventis 03/01/2010 8,121,355 03/03/2014 02/28/2020 54.12 — Sanofi-aventis 03/09/2011 874,500 03/10/2015 03/09/2021 50.48 32,448 Sanofi-aventis 03/05/2012 814,050 03/06/2016 03/05/2022 56.44 173,867 Sanofi 03/05/2013 788,725 03/06/2017 03/05/2023 72.19 380,256 Sanofi 03/05/2014 1,009,250 03/06/2018 03/05/2024 73.48 634,265 Sanofi 06/24/2015 435,000 06/25/2019 06/24/2025 89.38 339,964 Sanofi 05/04/2016 402,750 05/05/2020 05/04/2026 75.90 284,250 Sanofi 05/10/2017 378,040 05/11/2021 05/10/2027 88.97 294,220 Sanofi 05/02/2018 220,000 05/03/2022 05/02/2028 65.84 220,000 Sanofi 04/30/2019 220,000 05/02/2023 04/30/2029 76.71 220,000 Total 2,579,270
Summary of Stock Options Outstanding at Each Balance Sheet Date	A summary of stock options outstanding at each balance sheet date, and of movements during the relevant periods, is presented below: Number of Weighted average Total Options outstanding at January 1, 2018 7,889,020 60.08 474 Options exercisable 5,812,165 52.93 308 Options granted 220,000 65.84 14 Options exercised (1,192,838) 50.02 (60) Options cancelled (a) (66,609) 82.03 (5) Options outstanding at December 31, 2018 6,849,573 61.81 423 Options exercisable 5,468,214 56.80 311 Options granted 220,000 76.71 17 Options exercised (2,816,123) 53.18 (150) Options cancelled (a) (48,005) 72.84 (3) Options forfeited (383,425) 44.90 (17) Options outstanding at December 31, 2019 3,822,020 70.58 270 Options exercisable 2,650,375 67.14 178 Options exercised (868,655) 59.20 (52) Options cancelled (a) (91,305) 87.73 (8) Options forfeited (282,790) 54.12 (15) Options outstanding at December 31, 2020 2,579,270 75.61 195 Options exercisable 1,845,050 74.51 137 (a) Mainly due to the grantees leaving Sanofi.
Summary of Options Outstanding and Exercisable	The table below provides summary information about options outstanding and exercisable as of December 31, 2020: Outstanding Exercisable Range of exercise prices per share Number of Weighted Weighted Number of Weighted From €50.00 to €60.00 per share 206,315 1.02 55.50 206,315 55.50 From €60.00 to €70.00 per share 220,000 7.34 65.84 — — From €70.00 to €80.00 per share 1,518,771 4.08 74.08 1,298,771 73.63 From €80.00 to €90.00 per share 634,184 5.35 89.19 339,964 89.38 Total 2,579,270 1,845,050
Summary of Number of Shares Used to Compute Diluted Earnings Per Share	(million) 2020 2019 2018 Average number of shares outstanding 1,253.6 1,249.9 1,247.1 Adjustment for stock options with dilutive effect 0.4 0.8 1.3 Adjustment for restricted shares 6.1 6.4 6.8 Average number of shares used to compute diluted earnings per share 1,260.1 1,257.1 1,255.2

Debt, cash and cash equivalen_2

Debt, cash and cash equivalents and lease liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Financial Instruments [Abstract]
Summary of Changes in Financial Position	Changes in Sanofi's financial position during the period were as follows: (€ million) 2020 2019 2018 Long-term debt 19,745 20,131 22,007 Short-term debt and current portion of long-term debt 2,767 4,554 2,633 Interest rate and currency derivatives used to manage debt 119 (117) (54) Total debt 22,631 24,568 24,586 Cash and cash equivalents (13,915) (9,427) (6,925) Interest rate and currency derivatives used to manage cash and cash equivalents 74 (34) (33) Net debt (a) 8,790 15,107 17,628 (a) Following the first-time application of IFRS 16 effective January 1, 2019, net debt does not include lease liabilities, which amounted to €1,163 million as of December 31, 2020 and € 1,248 million as of December 31, 2019 (see the maturity analysis at Note D.17.2.). “Net debt” is a non-GAAP financial measure used by management and investors to measure Sanofi’s overall net indebtedness.
Summary of Reconciliation of Carrying Amount to Value on Redemption	Reconciliation of carrying amount to value on redemption Value on redemption (€ million) Carrying amount at December 31, 2020 Amortized Adjustment December 31, 2020 December 31, 2019 December 31, 2018 Long-term debt 19,745 70 (21) 19,794 20,180 22,071 Short-term debt and current portion of long-term debt 2,767 (2) 2 2,767 4,553 2,613 Interest rate and currency derivatives used to manage debt 119 23 142 (86) (12) Total debt 22,631 68 4 22,703 24,647 24,672 Cash and cash equivalents (13,915) (13,915) (9,427) (6,925) Interest rate and currency derivatives used to manage cash and cash equivalents 74 74 (34) (33) Net debt 8,790 68 4 8,862 15,186 17,714
Disclosure of Movement in Total Debt	The table below shows the movement in total debt during the period: Cash flows from Non-cash items (€ million) December 31, 2019 Repayments New Other Currency Reclassification Other items (a) December 31, 2020 Long-term debt 20,131 — 2,019 — (152) (2,285) 32 19,745 Short-term debt and current portion of long-term debt 4,554 (3,952) — 86 (219) 2,285 13 2,767 Interest rate and currency derivatives used to manage debt (117) — — 196 (14) — 54 119 Total debt 24,568 (3,952) 2,019 282 (385) — 99 22,631 (a) Includes fair value remeasurements.
Summary of Debt by Type Valuation of Redemption	2020 2019 2018 (€ million) Non- current Current Total Non- Current Total Non- Current Total Bond issues 19,698 2,280 21,978 20,128 4,079 24,207 21,983 2,181 24,164 Other bank borrowings 96 200 296 40 156 196 57 176 233 Finance lease obligations (b) – – – – – – 18 4 22 Other borrowings – 2 2 13 12 25 13 3 16 Bank credit balances – 285 285 – 305 305 – 249 249 Interest rate and currency derivatives used to manage debt 57 85 142 – (86) (86) – (12) (12) Total debt 19,851 2,852 22,703 20,181 4,466 24,647 22,071 2,601 24,672 Cash and cash equivalents – (13,915) (13,915) – (9,427) (9,427) – (6,925) (6,925) Interest rate and currency derivatives used to manage cash and cash equivalents 6 68 74 (6) (28) (34) – (33) (33) Net debt (a) 19,857 (10,995) 8,862 20,175 (4,989) 15,186 22,071 (4,357) 17,714 (a) Following the first-time application of IFRS 16 effective January 1, 2019, net debt does not include lease liabilities (see the maturity schedule in Note D.17.2.). (b) Following the first-time application of IFRS 16 effective January 1, 2019, the finance lease obligation as of that date was reclassified to Lease liabilities .
Summary of Bond Issues	Bond issues carried out by Sanofi under the Euro Medium Term Note (EMTN) program are as follows: Issuer ISIN code Issue date Maturity Annual interest rate Amount (€ million) Sanofi FR0011625433 November 2013 November 2023 2.5 % 1,000 Sanofi FR0012146777 September 2014 March 2022 1.125 % 1,000 Sanofi FR0012146801 September 2014 September 2026 1.75 % 1,510 Sanofi FR0012969020 September 2015 September 2021 0.875 % 500 Sanofi FR0012969038 September 2015 September 2025 1.5 % 750 Sanofi FR0013143997 April 2016 April 2024 0.625 % 600 Sanofi FR0013144003 April 2016 April 2028 1.125 % 700 Sanofi FR0013201621 September 2016 September 2022 - % 850 Sanofi FR0013201639 September 2016 January 2027 0.5 % 1,150 Sanofi FR0013505104 March 2020 April 2025 1 % 1,000 Sanofi FR0013505112 March 2020 April 2030 1.5 % 1,000 Sanofi FR0013324332 March 2018 March 2023 0.5 % 1,750 Sanofi FR0013324340 March 2018 March 2026 1 % 1,500 Sanofi FR0013324357 March 2018 March 2030 1.375 % 2,000 Sanofi FR0013324373 March 2018 March 2038 1.875 % 1,250 Sanofi FR0013409836 March 2019 March 2022 - % 850 Sanofi FR0013409844 March 2019 March 2029 0.875 % 650 Sanofi FR0013409851 March 2019 March 2034 1.25 % 500 Bond issues carried out by Sanofi under the public bond issue program (shelf registration statement) registered with the US Securities and Exchange Commission (SEC) comprise: Issuer ISIN code Issue date Maturity Annual interest rate Amount ($ million) Sanofi US80105NAG07 March 2011 March 2021 4 % 2,000 Sanofi US801060AC87 June 2018 June 2023 3.375 % 1,000 Sanofi US801060AD60 June 2018 June 2028 3.625 % 1,000
Summary of Debt by Maturity at Value on Redemption	December 31, 2020 Current Non-current (€ million) Total 2021 2022 2023 2024 2025 2026 and later Bond issues 21,978 2,280 2,700 3,569 600 1,750 11,079 Other bank borrowings 296 200 73 6 2 6 9 Finance lease obligations (b) – – – – – – – Other borrowings 2 2 – – – – – Bank credit balances 285 285 – – – – – Interest rate and currency derivatives used to manage debt 142 85 57 – – – – Total debt 22,703 2,852 2,830 3,575 602 1,756 11,088 Cash and cash equivalents (13,915) (13,915) – – – – – Interest rate and currency derivatives used to manage cash and cash equivalents 74 68 6 – – – – Net debt (a) 8,862 (10,995) 2,836 3,575 602 1,756 11,088 (a) Following the first-time application of IFRS 16 effective January 1, 2019, net debt does not include lease liabilities, which amounted to €1,163 million as of December 31, 2020 and €1,248 million as of December 31, 2019 (see the maturity analysis at Note D.17.2.). (b) Following the first-time application of IFRS 16 effective January 1, 2019, the finance lease obligation as of that date was reclassified to Lease liabilities . December 31, 2019 Current Non-current (€ million) Total 2020 2021 2022 2023 2024 2025 and later Bond issues 24,207 4,079 2,284 2,700 3,642 600 10,902 Other bank borrowings 196 156 6 6 23 5 – Finance lease obligations – – – – – – – Other borrowings 25 12 – – – – 13 Bank credit balances 305 305 – – – – – Interest rate and currency derivatives used to manage debt (86) (86) – – – Total debt 24,647 4,466 2,290 2,706 3,665 605 10,915 Cash and cash equivalents (9,427) (9,427) – – – – – Interest rate and currency derivatives used to manage cash and cash equivalents (34) (28) (6) – – – – Net debt 15,186 (4,989) 2,284 2,706 3,665 605 10,915 December 31, 2018 Current Non-current (€ million) Total 2019 2020 2021 2022 2023 2024 and later Bond issues 24,164 2,181 3,936 2,243 1,850 3,622 10,332 Other bank borrowings 233 176 15 3 3 28 8 Finance lease obligations 22 4 3 3 3 4 5 Other borrowings 16 3 — — — — 13 Bank credit balances 249 249 — — — — — Interest rate and currency derivatives used to manage debt (12) (12) — — — — — Total debt 24,672 2,601 3,954 2,249 1,856 3,654 10,358 Cash and cash equivalents (6,925) (6,925) — — — — — Interest rate and currency derivatives used to manage cash and cash equivalents (33) (33) — — — — — Net debt 17,714 (4,357) 3,954 2,249 1,856 3,654 10,358
Summary of Debt by Interest Rate	The table below splits net debt between fixed and floating rate, and by maturity, as of December 31, 2020. The figures shown are values on redemption, before the effects of derivative instruments: (€ million) Total 2021 2022 2023 2024 2025 2026 and later Fixed-rate debt 21,978 2,280 2,700 3,569 600 1,750 11,079 of which euro 18,703 of which US dollar 3,275 % fixed-rate 97 % Floating-rate debt 584 488 73 6 2 6 9 of which euro 35 of which US dollar 69 % floating-rate 3 % Debt 22,562 2,768 2,773 3,575 602 1,756 11,088 Cash and cash equivalents (13,915) (13,915) – – – – – of which euro (9,192) of which US dollar (4,278) % floating-rate 100 % Net debt 8,647 (11,147) 2,773 3,575 602 1,756 11,088 To optimize the cost of debt or reduce the volatility of debt and manage its exposure to financial foreign exchange risk, Sanofi uses derivative instruments (interest rate swaps, currency swaps, foreign exchange swaps and forward contracts) that alter the fixed/floating rate split and the currency split of its net debt: (€ million) Total 2021 2022 2023 2024 2025 2026 and later Fixed-rate debt 20,713 2,358 1,357 3,569 600 1,750 11,079 of which euro 17,752 of which US dollar 2,960 % fixed-rate 91 % Floating-rate debt 1,990 494 1,473 6 2 6 9 of which euro 415 of which US dollar 69 of which Japanese yen 215 % floating-rate 9 % Debt 22,703 2,852 2,830 3,575 602 1,756 11,088 Cash and cash equivalents (13,841) (13,847) 6 of which euro (4,442) of which US dollar (6,333) of which Singapore dollar (2,250) % floating-rate 100 % Net debt 8,862 (10,995) 2,836 3,575 602 1,756 11,088
Summary of Interest Rate of Net Debt at Value on Redemption	The table below shows the fixed/floating rate split of net debt at value on redemption after taking account of derivative instruments as of December 31, 2019 and December 31, 2018: (€ million) 2019 % 2018 % Fixed-rate debt 21,713 88 % 18,864 76 % Floating-rate debt 2,934 12 % 5,808 24 % Debt 24,647 100 % 24,672 100 % Cash and cash equivalents (9,461) (6,958) Net debt 15,186 17,714
Summary of Interest Rate Fluctuations of Debt Net of Cash and Cash Equivalents	The projected full-year sensitivity of net debt to interest rate fluctuations for 2021 is as follows: Change in short-term interest rates Impact on pre-tax net Impact on pre-tax +100 bp 119 – +25 bp 30 – -25 bp (30) – -100 bp (119) –
Summary of Debt by Currency	The table below shows net debt by currency at December 31, 2020, before and after derivative instruments contracted to convert the foreign-currency net debt of exposed entities into their functional currency: (€ million) Before derivative instruments After derivative instruments Euro 9,547 13,725 US dollar (933) (3,304) Singapore dollar (1) (2,250) Japanese yen — 214 Chinese yuan renminbi (9) (179) Other currencies 43 656 Net debt 8,647 8,862
Summary of Debt by Currency	The table below shows net debt by currency at December 31, 2019 and 2018, after derivative instruments contracted to convert the foreign currency net debt of exposed entities into their functional currency: (€ million) 2019 2018 Euro 17,691 16,511 US dollar (813) 2,197 Other currencies (1,692) (994) Net debt 15,186 17,714
Summary of Market Value of Net Debt	The market value of Sanofi’s debt, net of cash and cash equivalents and derivatives and excluding accrued interest, is as follows: (€ million) 2020 2019 2018 Market value 10,500 16,370 18,003 Value on redemption 8,862 15,186 17,714
Amount of Future Undiscounted Contractual Cash Flows Relating to Debt and Derivative Instruments Designated as Hedges of Debt	The table below shows the amount of future undiscounted contractual cash flows (principal and interest) relating to debt and to derivative instruments designated as hedges of debt: December 31, 2020 Payments due by period (€ million) Total 2021 2022 2023 2024 2025 2026 and later Debt 24,339 2,943 3,019 3,808 791 1,937 11,841 Principal 22,392 2,622 2,757 3,571 601 1,751 11,090 Interest (a) 1,947 321 262 237 190 186 751 Net cash flows related to derivative instruments 163 135 28 – – – – Total 24,502 3,078 3,047 3,808 791 1,937 11,841 (a) Interest flows are estimated on the basis of forward interest rates applicable as of December 31, 2020. The tables below show the amount of future undiscounted contractual cash flows (principal and interest) relating to debt and to derivative instruments designated as hedges of debt as of December 31, 2019 and 2018: December 31, 2019 Payments due by period (€ million) Total 2020 2021 2022 2023 2024 2025 and later Debt 26,708 4,775 2,588 2,952 3,862 771 11,760 Principal 24,596 4,417 2,305 2,710 3,646 604 10,914 Interest (a) 2,112 358 283 242 216 167 846 Net cash flows related to derivative instruments (117) (97) (11) (9) Total 26,591 4,678 2,577 2,943 3,862 771 11,760 (a) Interest flows are estimated on the basis of forward interest rates applicable as of December 31, 2019. December 31, 2018 Payments due by period (€ million) Total 2019 2020 2021 2022 2023 2024 and later Debt 26,881 2,855 4,300 2,519 2,088 3,856 11,263 Principal 24,550 2,477 3,955 2,250 1,858 3,653 10,357 Interest (a) 2,331 378 345 269 230 203 906 Net cash flows related to derivative instruments (50) (45) (8) (1) 4 — — Total 26,831 2,810 4,292 2,518 2,092 3,856 11,263 (a) Interest flows are estimated on the basis of forward interest rates applicable as of December 31, 2018.
Disclosure of Lease Liabilities	A maturity analysis of lease liabilities as of December 31, 2020 and 2019 is set forth below: Undiscounted future minimum lease payments (€ million) Total Less than 1 year From 1 to 3 years From 3 to 5 years More than 5 years Discounting effect Total lease liabilities as of December 31, 2020 1,163 247 357 225 482 (148) Total lease liabilities as of December 31, 2019 1,248 272 422 232 540 (218)

Liabilities related to busine_2

Liabilities related to business combinations and to non-controlling interests (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations 1 [Abstract]
Summary of Movements in Liabilities Related to Business Combinations and to Non-Controlling Interests	Movements in liabilities related to business combinations and to non-controlling interests are shown below: (€ million) Liabilities related to non-controlling interests (a) CVRs issued in connection with the acquisition of Genzyme (b) Bayer contingent consideration arising from the acquisition of Genzyme MSD Other Total (c) Balance at January 1, 2018 92 75 701 420 81 1,369 New transactions (e) — — — — 228 228 Payments made (70) — (147) (57) (55) (329) Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount) (d) — 19 (109) 50 3 (37) Other movements — — — — 24 24 Currency translation differences — 5 27 (3) 20 49 Balance at December 31, 2018 22 99 472 410 301 1,304 Payments made — — (113) (69) (55) (237) Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount) (d) — 49 (214) 38 81 (46) Other movements (22) (153) — — (73) (248) Currency translation differences — 5 11 6 5 27 Balance at December 31, 2019 — — 156 385 259 800 Payments made — — (42) (78) (2) (122) Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount) (d) — — 9 9 (53) (35) Other movements — — (8) — (2) (10) Currency translation differences — — (11) (4) (13) (28) Balance at December 31, 2020 — — 104 312 189 605 (a) Includes put options granted to non-controlling interests expired in 2019, and a commitment to a future buyout of non-controlling interests held by BMS (the payment relating to that buyout had been made as of December 31, 2018: see Note C.2.). (b) Based on the quoted market price per CVR of $0.72 as of October 30, 2019 and $0.48 as of December 31, 2018. The CVR agreement was terminated in March 2020 following signature of a litigation settlement agreement. (c) Portion due after more than one year: €387 million as of December 31, 2020 (€508 million as of December 31, 2019 and €963 million as of December 31, 2018); portion due within less than one year: €218 million as of December 31, 2020 (€292 million as of December 31, 2019 and €341 million as of December 31, 2018). (d) Amounts reported within the income statement line item Fair value remeasurement of contingent consideration , and mainly comprising unrealized gains and losses. (e) Includes €226 million for contingent consideration liabilities in favor of True North Therapeutics and €2 million of liabilities owed to Bioverativ employees at the acquisition date.
Summary of Maximum Amount of Contingent Consideration Payable and Firm Commitments to Buy Out Non-Controlling Interests	The table below sets forth the maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests: December 31, 2020 Total Payments due by period (€ million) Less than From 1 to From 3 to More than Commitments relating to contingent consideration in connection with business combinations (a) 1,043 228 351 192 272 (a) Includes €0.4 billion for the Bayer contingent consideration and €0.4 billion for the MSD contingent consideration.

Provisions, income tax liabil_2

Provisions, income tax liabilities and other liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Subclassifications of assets, liabilities and equities [abstract]
Summary of Non Current Provisions and Other Non-current Liabilities	The line item Non current provisions and other non-current liabilities comprises the following: (€ million) 2020 2019 2018 Provisions 7,219 7,353 6,883 Other non-current liabilities (a) 317 288 323 Total 7,536 7,641 7,206 (a) Includes derivative financial instruments: €92 million as of December 31, 2020, €10 million as of December 31, 2019, €7 million as of December 31, 2018.
Summary of Movements in Non-current Provisions	The table below sets forth movements in non-current provisions for the reporting periods presented: (€ million) Provisions for Provisions Restructuring Other Total Balance at January 1, 2018 3,959 750 514 1,975 7,198 Changes in scope of consolidation (6) (2) — 37 29 Increases in provisions 251 (a) 93 387 306 (b) 1,037 Provisions utilized (529) (a) (101) (3) (160) (793) Reversals of unutilized provisions (36) (a) (5) (15) (190) (246) Transfers (22) 10 (251) (26) (289) Net interest related to employee benefits, and unwinding of discount 70 4 — 24 98 Unrealized gains and losses — — — — — Currency translation differences 36 12 — 2 50 Actuarial gains and losses on defined-benefit plans (c) (201) — — — (201) Balance at December 31, 2018 3,522 761 632 1,968 6,883 Changes in scope of consolidation (1) — — — (1) Increases in provisions 213 (a) 189 393 554 (b) 1,349 Provisions utilized (285) (a) (102) (3) (132) (522) Reversals of unutilized provisions (209) (a) (3) (15) (511) (d) (738) Transfers 92 (3) (411) 168 (154) Net interest related to employee benefits, and unwinding of discount 83 5 3 18 109 Unrealized gains and losses — — — — — Currency translation differences 35 8 1 6 50 Actuarial gains and losses on defined-benefit plans (c) 377 — — — 377 Balance at December 31, 2019 3,827 855 600 2,071 7,353 Changes in scope of consolidation (3) — — 8 5 Increases in provisions 253 (a) 169 688 369 1,479 Provisions utilized (566) (a) (109) (5) (113) (793) Reversals of unutilized provisions (233) (a) (5) (42) (245) (525) Transfers 12 — (369) (64) (421) Net interest related to employee benefits, and unwinding of discount 57 2 1 8 68 Unrealized gains and losses — — — — — Currency translation differences (117) (33) (5) (59) (214) Actuarial gains and losses on defined-benefit plans (c) 267 — — — 267 Balance at December 31, 2020 3,497 879 868 1,975 7,219 (a) In the case of “Provisions for pensions and other post-employment benefits”, the “Increases in provisions” line corresponds to rights vesting in employees during the period, and past service cost; the “Provisions utilized” line corresponds to contributions paid into pension funds, and plan settlements; and the “Reversals of unutilized provisions” line corresponds to plan curtailments, settlements and amendments.. (b) Amounts charged during the period include changes to estimates of future expenditures on environmental risks. (c) Amounts recognized in Other comprehensive income (see Note D.15.7.). (d) This amount mainly comprises a reversal of a provision resulting from a settlement of litigation (see Note D.28.).
Summary of Financial and Demographic Assumptions	Those calculations were based on the following financial and demographic assumptions: 2020 2019 2018 France Germany USA UK France Germany USA UK France Germany USA UK Discount rate (a)/(b) 0.00% or 0.55% 0.00% or 0.55% 2.40 % 1.35 % 0.25% or 0.75% 0.25% or 0.75% 3.00 % 2.00 % 1.25% or 1.75% 1.25% or 1.75% 4.00 % 3.00 % General inflation rate (c) 1.45 % 1.45 % 2.00 % 2.95 % 1.30 % 1.30 % 2.00 % 2.85 % 1.50 % 1.50 % 2.00 % 3.10 % Pension benefit 1.45% 1.45 % — 2.85 % 1.25% to 2.25% 1.30 % — 2.80 % 1.25% to 2.25% 1.50 % — 3.00 % Healthcare cost — — (d) 3.50% to 4.50% 4.45 % (e) 2.00 % — (d) 5.52 % 4.35 % 2.00 % — (d) 5.66 % 1.50 % Retirement age 62 to 67 62 55 to70 60 to 65 62 to 67 62 55 to 70 60 to 65 62 to 67 62 55 to 70 60 to 65 Mortality table TGH/ Heubeck RP2012 Proj. SAPS TGH/ Heubeck RP2014 SAPS TGH/ Heubeck RP2014 SAPS (a) The discount rates used were based on market rates for high quality corporate bonds with a duration close to that of the expected benefit payments under the plans. The benchmarks used to determine discount rates were the same for all periods presented. (b) The rate depends on the duration of the plan (0 to 7 years, 7 to 10 years, or more than 10 years). (c) Inflation for the euro zone is determined using a multi-criterion method. (d) No post-employment healthcare benefits are provided in Germany. (e) Healthcare cost inflation rate in the United Kingdom of 1.50% above the general inflation rate.
Summary of Weighted Average Duration of Obligation for Pensions and Other Long-term Benefits in Principal Countries	The table below shows the duration of Sanofi’s obligations in the principal countries: 2020 2019 2018 (years) France Germany USA UK France Germany USA UK France Germany USA UK Weighted average duration 13 16 16 18 13 15 14 17 13 15 13 17
Summary of Sensitivity for Pensions and Other Post-employment Benefits to Changes in Key Actuarial Assumptions	The table below shows the sensitivity of Sanofi’s obligations for pensions and other post-employment benefits to changes in key actuarial assumptions: (€ million) Pensions and other post-employment benefits, by principal country Measurement of defined-benefit obligation Change in France Germany USA UK Discount rate -0.50 % +140 +272 +171 +337 General inflation rate +0.50 % +64 +377 +1 +216 Pension benefit indexation +0.50 % +71 +367 — +160 Healthcare cost inflation rate +0.50 % — — +14 — Mortality table +1 year +41 +83 +55 +154
Reconciliation of Net Obligation in Respect of Sanofi's Pension and Other Post-Employment Benefit Plans	The table below reconciles the net obligation in respect of Sanofi’s pension and other post-employment benefit plans with the amounts recognized in the consolidated financial statements: Pensions and other post-employment benefits (€ million) 2020 2019 2018 Measurement of the obligation: Beginning of period 13,322 12,055 13,012 Current service cost 218 199 231 Interest cost 194 293 260 Actuarial losses/(gains) due to changes in demographic assumptions 41 (61) 204 Actuarial losses/(gains) due to changes in financial assumptions 946 1,481 (841) Actuarial losses/(gains) due to experience adjustments (24) (119) (14) Plan amendments, curtailments or settlements not specified in the terms of the plan (a) (945) (259) (96) Plan settlements specified in the terms of the plan (75) (78) (83) Benefits paid (545) (504) (647) Changes in scope of consolidation and transfers (12) 13 (46) Currency translation differences (443) 302 75 Obligation at end of period 12,677 13,322 12,055 Fair value of plan assets: Beginning of period 9,651 8,610 9,106 Interest income on plan assets 138 211 190 Difference between actual return and interest income on plan assets 696 926 (450) Administration costs (14) (7) (8) Plan settlements specified in the terms of the plan (75) (78) (83) Plan settlements not specified in the terms of the plan (739) (64) (78) Contributions from plan members 6 6 6 Employer’s contributions 490 250 392 Benefits paid (469) (470) (510) Changes in scope of consolidation and transfers — — 6 Currency translation differences (326) 267 39 Fair value of plan assets at end of period 9,358 9,651 8,610 Net amount shown in the balance sheet: Net obligation 3,319 3,671 3,445 Effect of asset ceiling 1 1 — Net amount shown in the balance sheet at end of period 3,320 3,672 3,445 Amounts recognized in the balance sheet: Pre-funded obligations (see Note D.7.) (177) (155) (77) Obligations provided for 3,497 3,827 3,522 Net amount recognized at end of period 3,320 3,672 3,445 Benefit cost for the period: Current service cost 218 199 231 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (a) (206) (195) (18) Net interest (income)/cost 57 83 70 Contributions from plan members (7) (6) (6) Administration costs and taxes paid during the period 14 7 8 Expense recognized directly in profit or loss 76 88 285 Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses) 267 377 (201) Expense/(gain) for the period 343 465 84 (a) For 2019, this line mainly comprises the favorable impact of the amendment to the remaining top-up pension plan, following the application of the Pacte law in France. For 2020, it mainly comprises a reduction in post-employment benefit liabilities following the announcement of voluntary redundancy programs, primarily in Europe.
Net Liability in Respect of Pension Plans and Other Post-employment Benefits by Geographical Region	The tables below show Sanofi’s net liability in respect of pension plans and other post-employment benefits by geographical region: (€ million) Pensions and other post-employment benefits by geographical region December 31, 2020 France Germany USA UK Other Total Measurement of obligation 1,999 3,580 2,091 3,561 1,446 12,677 Fair value of plan assets 906 2,661 1,077 3,536 1,178 9,358 Effect of asset ceiling — — — — 1 1 Net amount shown in the balance sheet at end of period 1,093 919 1,014 25 269 3,320 (€ million) Pensions and other post-employment benefits by geographical region December 31, 2019 France Germany USA UK Other Total Measurement of obligation 2,077 3,470 2,948 3,388 1,439 13,322 Fair value of plan assets 956 2,516 1,774 3,258 1,147 9,651 Effect of asset ceiling — — — — 1 1 Net amount shown in the balance sheet at end of period 1,121 954 1,174 130 293 3,672 (€ million) Pensions and other post-employment benefits by geographical region December 31, 2018 France Germany USA UK Other Total Measurement of obligation 2,091 3,262 2,597 2,858 1,247 12,055 Fair value of plan assets 931 2,217 1,622 2,862 978 8,610 Net amount shown in the balance sheet at end of period 1,160 1,045 975 (4) 269 3,445
Fair Value of Plans Assets relating to Pension Plans and Other Post-employment Plans	The table below shows the fair value of plan assets relating to Sanofi’s pension and other post-employment plans, split by asset category: 2020 2019 2018 Securities quoted in an active market 94.8 % 87.4 % 99.2 % Cash and cash equivalents 3.5 % 1.8 % 1.4 % Equity instruments 24.8 % 22.6 % 22.3 % Bonds and similar instruments 59.9 % 55.8 % 66.5 % Real estate 3.4 % 3.8 % 4.2 % Commodities 0.9 % 0.9 % 0.7 % Other 2.3 % 2.5 % 4.1 % Other securities 5.2 % 12.6 % 0.8 % Hedge funds 0.4 % — % — % Insurance policies 4.8 % 12.6 % 0.8 % Total 100.0 % 100.0 % 100.0 %
Service Cost for Pension and Other post-employment Benefit Plans, by Geographical Region	The tables below show the service cost for Sanofi’s pension and other post-employment benefit plans, by geographical region: (€ million) Pensions and other post-employment benefits by geographical region Service cost for 2020 France Germany USA UK Other Total Current service cost 62 49 51 — 56 218 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (94) 10 (123) — 1 (206) Net interest cost/(income) including administration costs and taxes paid during the period 9 13 34 5 10 71 Contributions from plan members — — — — (7) (7) Expense/(gain) recognized directly in profit or loss (23) 72 (38) 5 60 76 Remeasurement of net defined-benefit (asset)/ liability (actuarial gains and losses) 24 121 22 115 (15) 267 Expense/(gain) for the period 1 193 (16) 120 45 343 (€ million) Pensions and other post-employment benefits by geographical region Service cost for 2019 France Germany USA UK Other Total Current service cost 62 42 42 — 53 199 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (193) 13 (12) (2) (1) (195) Net interest cost/(income) including administration costs and taxes paid during the period 20 17 40 2 11 90 Contributions from plan members — — — — (6) (6) Expense/(gain) recognized directly in profit or loss (111) 72 70 — 57 88 Remeasurement of net defined-benefit (asset)/ liability (actuarial gains and losses) 89 (4) 148 133 11 377 Expense/(gain) for the period (22) 68 218 133 68 465 (€ million) Pensions and other post-employment benefits by geographical region Service cost for 2018 France Germany USA UK Other Total Current service cost 78 51 46 — 56 231 (Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan (5) (20) 3 5 (1) (18) Net interest cost/(income) including administration costs and taxes paid during the period 17 12 35 4 10 78 Contributions from plan members — — — — (6) (6) Expense/(gain) recognized directly in profit or loss 90 43 84 9 59 285 Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses) (155) (13) (38) 7 (2) (201) Expense/(gain) for the period (65) 30 46 16 57 84
Remeasurement of Net Defined-benefit (Asset)/Liability (Actuarial Gains and Losses)	An analysis of the “Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)” line in the preceding tables is set forth below: (€ million) 2020 2019 2018 France Germany USA UK France Germany USA UK France Germany USA UK Actuarial gains/(losses) arising during the period (a) (24) (121) (22) (115) (89) 5 (148) (133) 155 13 38 (7) Comprising: Gains/(losses) on experience adjustments (b) 26 76 214 341 149 331 210 242 21 (154) (131) (118) Gains/(losses) 20 — (42) (14) — — — 63 (7) (67) 7 (144) Gains/(losses) (70) (197) (194) (442) (238) (326) (358) (438) 141 234 162 255 (a) Gains and losses arising from changes in assumptions are due primarily to changes in the discount rate. (b) Experience adjustments are mainly due to the effect of trends in the financial markets on plan assets.
Summary of Net Pre-tax Actuarial Loss	The net pre-tax actuarial loss (excluding investments accounted for using the equity method) recognized directly in equity is presented below: (€ million) 2020 2019 2018 Net pre-tax actuarial loss (3,471) (3,207) (2,834)
Summary of Present Value of Pension and Other Post Employement Benefits	The present value of Sanofi’s obligations in respect of pension and other post-employment benefit plans at the end of each reporting period is shown below: (€ million) 2020 2019 2018 Present value of wholly or partially funded obligations in respect of pension and other post-employment benefit plans 11,543 12,057 10,995 Present value of unfunded obligations 1,134 1,265 1,060 Total 12,677 13,322 12,055
Total Expense for Pensions and Other Post-employment Benefits Allocated between Income Statement Line Items	The total expense for pensions and other post-employment benefits (€76 million in 2020) is allocated between income statement line items as follows: (€ million) 2020 2019 2018 Cost of sales 75 46 67 Research and development expenses 62 25 77 Selling and general expenses (34) (22) 84 Other operating (income)/expenses, net (18) (3) (21) Restructuring costs (66) (41) 8 Financial expenses 57 83 70 Total 76 88 285
Estimated Amounts of Employer's Contributions to Plan Assets	The estimated amounts of employer’s contributions to plan assets in 2021 are as follows: (€ million) France Germany USA UK Other Total Employer’s contributions in 2021 (estimate): 2021 — — — 3 39 42
Expected Timing of Benefit Payments under Pension and Other Post-employment Benefit Plans	The table below shows the expected timing of benefit payments under pension and other post-employment benefit plans for the next ten years: (€ million) France Germany USA UK Other Total Estimated future benefit payments: 2021 145 186 95 119 62 607 2022 64 190 88 122 53 517 2023 74 195 88 126 56 539 2024 84 199 91 130 60 564 2025 80 203 85 134 58 560 2026 to 2029 529 1,024 439 734 340 3,066
Timing of Future Payments in Respect of Unfunded Pension and Other Post-employment Benefit Plans	The table below shows estimates as of December 31, 2020 for the timing of future payments in respect of unfunded pension and other post-employment benefit plans: Total Payments due by period (€ million) Less than 1 year 1 to 3 to More than Estimated payments 1,134 61 99 102 872
Movements in Restructuring Provisions Classified in Non-current and Current Liabilities	The table below shows movements in restructuring provisions classified in non-current and current liabilities: (€ million) 2020 2019 2018 Balance, beginning of period 1,390 1,572 1,086 Of which: • Classified in non-current liabilities 600 632 514 • Classified in current liabilities 790 940 572 Change in provisions recognized in profit or loss for the period 767 760 1,035 Provisions utilized (663) (897) (605) Transfers 20 (51) 54 Unwinding of discount 1 3 — Currency translation differences (16) 3 2 Balance, end of period 1,499 1,390 1,572 Of which: • Classified in non-current liabilities 868 600 632 • Classified in current liabilities 631 790 940
Timing of Future Termination Benefit Payments	The timing of future termination benefit payments is as follows: December 31, 2020 Total Benefit payments by period (€ million) Less than 1 to 3 to More than Employee termination benefits • France 889 295 457 124 13 • Other countries 371 195 149 18 9 Total 1,260 490 606 142 22 December 31, 2019 Benefit payments by period (€ million) Total Less than 1 to 3 to More than Employee termination benefits • France 694 314 268 110 2 • Other countries 431 343 79 6 3 Total 1,125 657 347 116 5 December 31, 2018 Benefit payments by period (€ million) Total Less than 1 to 3 to More than Employee termination benefits • France 623 302 242 71 8 • Other countries 272 187 62 6 17 Total 895 489 304 77 25
Summary of Other Provisions	Other provisions include provisions for risks and litigation relating to environmental, tax, commercial and product liability matters. (€ million) 2020 2019 2018 Environmental risks 713 737 680 Product liability risks, litigation and other 1,262 1,334 1,288 Total 1,975 2,071 1,968
Current Provisions and Other Current Liabilities	Current provisions and other current liabilities comprise the following: (€ million) 2020 2019 2018 Taxes payable, other than corporate income taxes 347 361 393 Employee-related liabilities 2,042 1,978 1,989 Restructuring provisions (see Note D.19.2.) 631 790 940 Interest rate derivatives (see Note D.20.) — 2 — Currency derivatives (see Note D.20.) 205 87 90 Amounts payable for acquisitions of non-current assets 467 413 497 Customer contract liabilities (a) 252 — — Other current liabilities (b) 6,188 6,072 5,060 Total 10,132 9,703 8,969 (a) See Note A.7. , "Agreements relating to the recombinant Covid-19 vaccine candidate developed by Sanofi in collaboration with GSK" . (b) As of December 31, 2019, the "Other current liabilities" line included $315 million deposited by Sanofi in an escrow account, the release of which occurred in March 2020 following the signature of a settlement agreement in the CVR litigation between Sanofi and the Trustee.

Derivative financial instrume_2

Derivative financial instruments and market risks (Tables)	12 Months Ended
	Dec. 31, 2020
Financial Instruments [Abstract]
Summary of Fair Value of Derivative Instruments	The table below shows the fair value of derivative instruments as of December 31, 2020, 2019 and 2018: (€ million) Non-current assets Current Total Non-current Current Total Market value at December 31, 2020 (net) Market value at December 31, 2019 (net) Market value at December 31, 2018 (net) Currency derivatives — 58 58 (62) (205) (267) (209) 103 44 operating — 26 26 — (19) (19) 7 (15) 7 financial — 32 32 (62) (186) (248) (216) 118 37 Interest rate derivatives 24 — 24 (4) — (4) 20 27 42 Equity derivatives — — — (26) — (26) (26) (4) Total 24 58 82 (92) (205) (297) (215) 126 86
Summary of Operating Currency Hedging Instruments	The table below shows operating currency hedging instruments in place as of December 31, 2020, with the notional amount translated into euros at the relevant closing exchange rate: December 31, 2020 Of which derivatives designated as Of which derivatives not (€ million) Notional Fair Notional Fair Of which Notional Fair value Forward currency sales 3,477 7 — — — 3,477 7 of which US dollar 1,367 10 — — — 1,367 10 of which Chinese yuan renminbi 521 2 — — — 521 2 of which Singapore dollar 287 (1) — — — 287 (1) of which Japanese yen 143 1 — — — 143 1 of which Mexican peso 121 — — — — 121 — Forward currency purchases 1,932 — — — — 1,932 — of which US dollar 580 (1) — — — 580 (1) of which Singapore dollar 571 (1) — — — 571 (1) of which Chinese yuan renminbi 286 1 — — — 286 1 of which Russian rouble 61 — — — — 61 — of which Japanese yen 55 — — — — 55 — Total 5,409 7 — — — 5,409 7 The table below shows operating currency hedging instruments in place as of December 31, 2019, with the notional amount translated into euros at the relevant closing exchange rate: December 31, 2019 Of which derivatives designated as Of which derivatives not (€ million) Notional Fair Notional Fair Of which Notional Fair value Forward currency sales 3,372 (10) – – – 3,372 (10) of which US dollar 1,186 3 – – – 1,186 3 of which Chinese yuan renminbi 447 — – – – 447 — of which Singapore dollar 410 — – – – 410 — of which Russian rouble 184 (3) – – – 184 (3) of which Saudi riyal 133 1 – – – 133 1 Forward currency purchases 1,835 (5) – – – 1,835 (5) of which US dollar 602 (6) – – – 602 (6) of which Singapore dollar 525 1 – – – 525 1 of which Chinese yuan renminbi 130 — – – – 130 — of which Hungarian forint 60 — – – – 60 — of which Russian rouble 49 — – – – 49 — Total 5,207 (15) – – – 5,207 (15) The table below shows operating currency hedging instruments in place as of December 31, 2018, with the notional amount translated into euros at the relevant closing exchange rate: December 31, 2018 Of which derivatives Of which derivatives not eligible for hedge accounting (€ million) Notional Fair Notional Fair Of which Notional Fair value Forward currency sales 4,002 — — — — 4,002 — of which US dollar 1,723 (7) — — — 1,723 (7) of which Singapore dollar 652 1 — — — 652 1 of which Chinese yuan renminbi 451 (1) — — — 451 (1) of which Saudi riyal 100 1 — — — 100 1 of which Russian rouble 88 5 — — — 88 5 Forward currency purchases 2,036 7 — — — 2,036 7 of which US dollar 514 8 — — — 514 8 of which Singapore dollar 500 1 — — — 500 1 of which Japanese yen 197 3 — — — 197 3 of which Chinese yuan renminbi 163 (1) — — — 163 (1) of which Canadian dollar 106 (2) — — — 106 (2) Total 6,038 7 — — — 6,038 7
Disclosure of Financial Currency Hedging Instruments in Place with Notional Amount Translated	The table below shows financial currency hedging instruments in place, with the notional amount translated into euros at the relevant closing exchange rate: 2020 2019 2018 (€ million) Notional Fair Expiry Notional Fair Expiry Notional Fair Expiry Forward currency sales 5,064 10 8,515 40 7,762 17 of which US dollar 3,721 (a) 20 2021 6,331 51 2020 5,500 38 2019 of which Japanese yen 283 — 2021 516 (5) 2020 973 (24) 2019 of which Pound sterling 257 (6) 2021 297 1 2020 184 — 2019 Forward currency purchases 9,004 (226) 10,975 78 7,291 20 of which US dollar 6,068 (b) (c) (200) 2022 7,363 42 2020 4,165 (17) 2019 of which Singapore dollar 2,250 (d) (27) 2021 2,332 32 2,022 33 2019 of which Chinese yuan renminbi 195 1 2021 270 2 2020 427 — 2019 Total 14,068 (216) 19,490 118 15,053 37 (a) Includes forward sales with a notional amount of $3,615 million expiring in 2021, designated as a hedge of Sanofi’s net investment in Bioverativ. As of December 31, 2020, the fair value of these forward contracts represented an asset of €13 million; the opposite entry was recognized in Other comprehensive income , with the impact on financial income and expense being immaterial. (b) Includes forward purchases with a notional amount of $3,000 million expiring in 2021 and 2022, designated as a fair value hedge of the exposure of $3,000 million of bond issues to fluctuations in the EUR/USD spot rate. As of December 31, 2020, the fair value of the contracts was a liability of €109 million. (c) Includes currency swaps with a notional amount of $1,000 million, receive 0.22% pay EUR -0.63% expiring in 2022, designated as a cash flow hedge of $1,000 million of bond issues. As of December 31, 2020, the fair value of the swaps was a liability of €38 million.
Disclosure of Instruments	December 31, 2020: Notional amounts by expiry date as of December 31, 2020 Of which Of which designated as (€ million) 2021 2022 2023 2024 2025 2026 Total Fair Notional Fair Notional Fair Of which Interest rate swaps pay capitalized Eonia / receive 0.06% — 2,000 — — — — 2,000 23 2,000 23 — — — pay -0.57% / receive capitalized Eonia — 600 — — — — 600 1 — — 600 1 1 receive capitalized Eonia / pay 1.48% (a) — 42 57 — — — 99 (4) 99 (4) — — — Total — 2,642 57 — — — 2,699 20 2,099 19 600 1 1 (a) These interest rate swaps hedge fixed-rate bonds with a nominal of €99 million held in a Professional Specialized Investment Fund dedicated to Sanofi and recognized within “Loans, advances and other long-term receivables” (see Note D.7.). The table below shows interest rate hedging instruments in place as of December 31, 2019: Notional amounts by expiry date as of December 31, 2019 Of which Of which designated as (€ million) 2020 2021 2022 2023 2024 2025 Total Fair Notional Fair Notional Fair Of which Interest rate swaps pay capitalized Eonia / receive 0.06% — — 2,000 — — — 2,000 28 2,000 28 — — — pay -0.57% / receive capitalized Eonia — — 600 — — — 600 3 — — 600 3 3 pay 1.81% / receive 3-month US dollar Libor 446 — — — — — 446 (2) — — 446 (2) — pay 3-month US dollar Libor / receive 2.22% 446 — — — — — 446 4 446 4 — — — receive capitalized Eonia / pay 1.48% — — 42 57 — — 99 (6) 99 (6) — — — Total 892 — 2,642 57 — — 3,591 27 2,545 26 1,046 1 3 The table below shows interest rate hedging instruments in place as of December 31, 2018: Notional amounts by expiry date as of December 31, 2018 Of which Of which designated as (€ million) 2019 2020 2021 2022 2023 2024 Total Fair Notional Fair Notional Fair Of which Interest rate swaps pay capitalized Eonia / receive 1.58% 1,550 — — — — — 1,550 30 1,550 30 — — — pay capitalized Eonia / receive 0.06% — — — 2,000 — — 2,000 15 2,000 15 — — — pay 1.81% / receive 3-month US dollar Libor — 436 — — — — 436 5 — — 436 5 7 pay 3-month US dollar Libor / receive 2.22% — 436 — — — — 436 (1) 436 (1) — — — receive capitalized Eonia / pay 1.48% — — — 42 57 — 99 (6) 99 (6) — — — Total 1,550 872 — 2,042 57 — 4,521 42 4,085 38 436 5 7
Disclosure of Actual or Potential Effects of Netting Arrangements	The table below is prepared in accordance with the accounting policies described in Note B.8.3.: (€ million) 2020 2019 2018 Derivative Derivative Derivative Derivative Derivative Derivative Gross carrying amounts before offset (a) 82 (297) 225 (99) 183 (97) Gross amounts offset (in accordance with IAS 32) (b) — — — — — — Net amounts as reported in the balance sheet (a) - (b) = (c) 82 (297) 225 (99) 183 (97) Effects of other netting arrangements (not fulfilling the IAS 32 criteria for offsetting) (d) — — Financial instruments (81) 81 (89) 89 (81) 81 Fair value of financial collateral N/A N/A N/A N/A N/A N/A Net exposure (c) + (d) 1 (216) 136 (10) 102 (16)

Off balance sheet commitments (

Off balance sheet commitments (Tables)	12 Months Ended
	Dec. 31, 2020
Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]
Summary of off balance sheet commitments relating to operating activities	Off balance sheet commitments relating to Sanofi’s operating activities comprise the following: December 31, 2020 Payments due by period (€ million) Total Less than 1 to 3 to More than Leases with a term of less than 12 months, low value asset leases and lease contracts committed but not yet commenced (a)(b) 950 39 118 118 675 Irrevocable purchase commitments (c) • given (d) 7,153 4,072 1,482 572 1,027 • received (608) (236) (168) (51) (153) Research and development license agreements - commitments given • commitments related to R&D and other commitments (e) 500 261 217 10 12 • probable milestone payments (f) 2,456 163 714 972 607 Total - net commitments given (g) 10,451 4,299 2,363 1,621 2,168 (a) Includes future variable lease payments not recognized in Lease liabilities as of December 31, 2020. The principal commitment on this line is a new lease in the United States that will commence in 2021. As of December 31, 2019, the amount of such commitments was €1,067 million. (b) Lease commitments given to joint ventures were immaterial as of December 31, 2020. (c) These comprise irrevocable commitments to suppliers of (i) property, plant and equipment, net of down-payments (see Note D.3.) and (ii) goods and services. As of December 31, 2019, irrevocable commitments amounted to €6,726 million given and €(648) million received. (d) Irrevocable purchase commitments given as of December 31, 2020 include €989 million of commitments to joint ventures. (e) Commitments related to R&D, and other commitments, amounted to €784 million as of December 31, 2019. (f) This line includes only contingent milestone payments on development projects in progress. The reduction relative to December 31, 2019 (when probable milestone payments amounted to €3,040 million) is mainly due to (i) the discontinuation of the collaboration with Hanmi and (ii) the ending of a pre-existing agreement with Principia Biopharma Inc. following the acquisition of that company by Sanofi in September 2020. (g) This line excludes: (i) commitments given relating to projects in the research phase (€6.7 billion in 2020, €6.7 billion in 2019) and payments contingent upon the attainment of sales targets once a product is commercialized (€8.1 billion in 2020, €10.6 billion in 2019); (ii) commitments received in respect of the additional share of quarterly profits to which Sanofi is entitled under the collaboration agreements with Regeneron on monoclonal antibodies (capped at 10% of Regeneron’s share of quarterly profits), until Regeneron has paid 50% of the cumulative development costs incurred by the parties in the collaboration (see Note C.1.). Such commitments received were €2.6 billion in 2020 (€2.7 billion in 2019), relative to cumulative development costs of €6.6 billion as of December 31, 2020 (€3.3 billion 100% financed by Sanofi, €3.3 billion financed 80% Sanofi, 20% Regeneron); and (iii) commitments received under other agreements amounting to €3.3 billion in 2020 (€3.2 billion in 2019), including discovery, development and commercialization agreements arising from (i) the acquisition of Ablynx on May 14, 2018 (see Note D.1.), amounting to €1.1 billion as of December 31, 2020 (€1.1 billion in 2019) and (ii) the sale to Celgene of Sanofi's equity interest in Impact Biomedicines in January 2018, amounting to €0.5 billion as of December 31, 2020 (€0.5 billion in 2019).
Summary of Undrawn Credit Facilities	Undrawn credit facilities are as follows: December 31, 2020 Total Expiry (€ million) Less than 1 to 3 to More than General-purpose credit facilities 8,000 4,000 — 4,000 —
Summary of amount of guarantees given and received	The table below shows the amount of guarantees given and received: (€ million) 2020 2019 2018 Guarantees given: 3,291 3,103 3,010 • Guarantees provided to banks in connection with credit facilities 695 1,263 1,307 • Other guarantees given 2,596 1,840 1,703 Guarantees received (964) (703) (190)

Provisions for discounts, reb_2

Provisions for discounts, rebates and sales returns (Tables)	12 Months Ended
	Dec. 31, 2020
Other Provisions, Contingent Liabilities And Contingent Assets [Abstract]
Summary of movement in provisions for discounts, rebates and sales returns	The table below shows movements in these items: (€ million) Government and State programs (a) Managed care and GPO programs (b) Chargeback Rebates Sales Other Total Balance at January 1, 2018 2,086 663 377 1,067 547 6 4,746 Changes in scope of consolidation 37 2 — (123) — 2 (82) Provision related to current period sales 4,624 2,038 3,620 5,942 465 56 16,745 Net change in provision related to prior period sales (2) (4) (1) (11) (35) 3 (50) Payments made (4,673) (2,055) (3,714) (5,732) (448) (54) (16,676) Currency translation differences 76 30 12 (3) 17 — 132 Balance at December 31, 2018 (c) 2,148 674 294 1,140 546 13 4,815 Provision related to current period sales 5,542 2,563 4,649 5,888 554 96 19,292 Net change in provision related to prior period sales (27) — (1) (6) (27) 14 (47) Payments made (5,529) (2,528) (4,637) (5,719) (465) (72) (18,950) Currency translation differences 44 17 7 27 13 — 108 Balance at December 31, 2019 (c) 2,178 726 312 1,330 621 51 5,218 Provision related to current period sales 5,970 2,752 4,633 6,221 628 110 20,314 Net change in provision related to prior period sales (54) — — (113) (34) — (201) Payments made (5,552) (2,556) (4,604) (5,838) (512) (112) (19,174) Currency translation differences (35) (14) (8) (43) (15) (3) (118) Balance at December 31, 2020 (c) 2,507 908 333 1,557 688 46 6,039 (a) Primarily US government programs: Medicaid (€1,015 million in 2020, €1,017 million in 2019, €1,033 million in 2018) and Medicare (€726 million in 2020, €810 million in 2019 and €829 million in 2018). (b) Mainly rebates and other price reductions granted to healthcare authorities in the United States (including Managed Care: €692 million in 2020, €649 million in 2019 and €604 million in 2018). (c) Provisions related to US net sales amounted to €3,982 million as of December 31, 2020, €3,585 million as of December 31, 2019 and €3,509 million as of December 31, 2018.

Personnel costs (Tables)

Personnel costs (Tables)	12 Months Ended
	Dec. 31, 2020
Employee Benefits [Abstract]
Summary of personal costs	Total personnel costs (other than termination benefits, presented in Note D.27.) include the following items: (€ million) 2020 2019 2018 Salaries 6,508 6,590 6,547 Social security charges (including defined-contribution pension plans) 1,874 1,949 1,954 Stock options and other share-based payment expense 274 252 282 Defined-benefit plans 159 119 261 Other employee benefits 261 229 225 Total 9,076 9,139 9,269

Other operating expenses (Table

Other operating expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Schedule Other Operating Expenses	For 2020, this line item includes €1,090 million of expenses relating to the alliance with Regeneron (see Note C.1.), versus €715 million for 2019 and €225 million in 2018 (as shown in the table below): (€ million) 2020 2019 2018 Income & expense related to profit/loss sharing under the Monoclonal Antibody Alliance (727) (253) 177 Additional share of profit paid by Regeneron towards development costs 75 21 — Reimbursement to Regeneron of selling expenses incurred (349) (449) (388) Total - Monoclonal Antibody Alliance (1,001) (681) (211) Immuno-Oncology Alliance 89 62 4 Other (mainly Zaltrap ® ) (14) (14) (14) Other operating income/(expenses), net related to the Regeneron Alliance (926) (633) (221) of which amount presented in Other operating income (Note D.25.) 164 82 4

Restructuring costs and simil_2

Restructuring costs and similar items (Tables)	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Summary of Restructuring Costs and Similar Items	Restructuring costs and similar items amounted to €1,064 million in 2020, €1,062 million in 2019 and €1,480 million in 2018, and comprise the following items: (€ million) 2020 2019 2018 Employee-related expenses 690 791 517 Charges, gains or losses on assets (a) 149 106 162 Compensation for early termination of contracts (other than contracts of employment) 40 49 352 Decontamination costs (2) 27 5 Other restructuring costs 187 89 444 Total 1,064 1,062 1,480

Financial expenses and income (

Financial expenses and income (Tables)	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Summary of Analysis of Financial Income and Expenses	An analysis of Financial expenses and Financial income is set forth below: (€ million) 2020 2019 2018 Cost of debt (a) (328) (318) (396) Interest income (b) 103 146 123 Cost of net debt (225) (172) (273) Non-operating foreign exchange gains/(losses) (6) 1 6 Unwinding of discounting of provisions (c) (11) (25) (24) Net interest cost related to employee benefits (59) (87) (75) Gains/(losses) on disposals of financial assets 6 — 63 Net interest expense on lease liabilities (d) (38) (39) — Other (4) 19 32 Net financial income/(expenses) (337) (303) (271) comprising: Financial expenses (390) (444) (435) Financial income 53 141 164 (a) Includes net gains on interest rate and currency derivatives used to manage debt: €93 million in 2020, €187 million in 2019 and €75 million in 2018. (b) Includes net gains on interest rate and currency derivatives used to manage cash and cash equivalents: €66 million in 2020, €55 million in 2019 and €51 million in 2018. (c) Primarily on provisions for environmental risks, restructuring provisions, and provisions for product-related risks (see Note D.19.). (d) Impact of the application of IFRS 16.

Income tax expense (Tables)

Income tax expense (Tables)	12 Months Ended
	Dec. 31, 2020
Income Taxes [Abstract]
Summary of Allocation of Income Tax Expense Between Current and Deferred Taxes	The table below shows the allocation of income tax expense between current and deferred taxes: (€ million) 2020 2019 2018 Current taxes (1,912) (1,892) (1,212) Deferred taxes 99 1,753 731 Total (1,813) (139) (481) Income before tax and investments accounted for using the equity method 13,804 2,822 4,405
Summary of Difference Between Effective Tax Rate and Standard Corporate Income Tax Rate	The difference between the effective tax rate and the standard corporate income tax rate applicable in France is explained as follows: (as a percentage) 2020 2019 2018 Standard tax rate applicable in France 32.0 34.4 34.4 Difference between the standard French tax rate and the rates applicable to Sanofi (a) (18.2) (22.9) (17.4) Revisions to tax exposures and settlements of tax disputes 0.5 4.8 (1.4) Impact of US tax reform (b) — — (4.3) Impact of past acquisitions and divestitures — (6.2) — Fair value remeasurement of contingent consideration (c) — (2.6) 0.2 Other items (d) (1.2) (2.6) (0.6) Effective tax rate 13.1 4.9 10.9 (a) The difference between the French tax rate and tax rates applicable to foreign subsidiaries reflects the fact that Sanofi has operations in many countries, most of which have lower tax rates than France. For 2020, this line includes the difference between the standard French tax rate and the tax rate applicable to the gain on divestment of Regeneron shares. (b) For 2018, this line reflects an adjustment of €188 million to the estimated tax charge on deemed repatriation attributable to the accumulated earnings of non-US operations. (c) For 2019, this line includes impacts related to the MSD contingent consideration and to the CVRs issued in connection with the acquisition of Genzyme. (d) In determining the amount of the deferred tax liability for 2020, 2019 and 2018, Sanofi took into account changes in the ownership structure of certain subsidiaries. For 2018, "Other items" also includes the net tax effect of taxable temporary differences associated with holdings in Sanofi subsidiaries.

Share of profit_loss from inv_2

Share of profit/loss from investments accounted for using the equity method (Tables)	12 Months Ended
	Dec. 31, 2020
Interests In Other Entities [Abstract]
Summary of share of profit/loss from investments accounted for using equity method	The line item Share of profit/(loss) from investments accounted for using the equity method comprises: (€ million) 2020 2019 2018 Regeneron (a) 343 245 484 BMS co-promotion entities (b) 1 5 12 Other investments accounted for using the equity method 15 5 3 Total 359 255 499 (a) Following the transaction of May 29, 2020 as described in Note D.1., which resulted in the divestment of 22.8 million Regeneron shares, Sanofi no longer exercises significant influence over Regeneron. The 2020 figure presented represents Sanofi’s equity-accounted share of Regeneron’s net profits up to and including that date. (b) On February 28, 2020, Sanofi acquired from Bristol-Myers Squibb the remaining 50.1% equity interest not yet held by Sanofi in the three partnerships that organize the commercialization of Plavix ® in the United States and Puerto Rico, for a total consideration of $12 million. This acquisition was accounted for in accordance with IFRS 3 (Business Combinations).

Net income attributable to no_2

Net income attributable to non-controlling interests (Tables)	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Summary of trends in net income attributable to non-controlling interests	The table below shows Net income attributable to non-controlling interests for the reporting periods presented: (€ million) 2020 2019 2018 Share of co-promotion profits attributable to BMS (a) — — 83 Share of net income attributable to other non-controlling interests 36 31 21 Total 36 31 104 (a) For 2018: share of co-promotion profits attributable to BMS for territories covered by entities majority owned by Sanofi; there was no tax effect on these amounts because BMS received its share before tax. The payment to buy out the BMS non-controlling interests was made on December 31, 2018 (see Note C.2.).

Related party transactions (Tab

Related party transactions (Tables)	12 Months Ended
	Dec. 31, 2020
Related Party [Abstract]
Schedule of compensation paid to key management personnel	The table below shows, by type, the compensation paid to key management personnel: (€ million) 2020 2019 2018 Short-term benefits (a) 36 31 38 Post-employment benefits (b) 3 (8) 9 Share-based payment 18 30 33 Total recognized in profit or loss 57 53 80 (a) Compensation, employer’s social security contributions, directors’ attendance fees, and any termination benefits (net of reversals of termination benefit obligations). (b) This line item includes in 2019 the favorable impact of top-up pension plan amendments following the application of the Pacte law in France.
Summary of aggregate amounts payable to key management personnel	The table below shows (i) the aggregate top-up pension obligation in favor of certain corporate officers who hold or have held executive positions within Sanofi and of Executive Committee members, and (ii) the aggregate amount of termination benefits and lump-sum retirement benefits payable to key management personnel. (€ million) 2020 2019 2018 Aggregate top-up pension obligation 28 48 59 Aggregate termination benefits and lump-sum retirement benefits 6 5 10

Segment information (Tables)

Segment information (Tables)	12 Months Ended
	Dec. 31, 2020
Operating Segments [Abstract]
Summary of Net Sales by Segment and Geographical Area	The table below sets forth Sanofi’s net sales for the years ended December 31, 2020, 2019 and 2018: (€ million) Europe United States Other 2020 Europe United Other 2019 (a) Europe United Other 2018 Pharmaceuticals 6,819 9,635 9,220 25,674 6,797 8,918 9,985 25,700 7,303 7,897 9,485 24,685 General Medicines 4,505 2,869 7,346 14,720 4,809 3,386 8,342 16,537 5,299 3,510 7,607 16,416 of which Lantus ® 537 929 1,195 2,661 599 1,149 1,264 3,012 684 1,614 1,267 3,565 Toujeo ® 374 267 292 933 343 289 251 883 290 344 206 840 Praluent ® 121 106 34 261 112 112 34 258 86 154 21 261 Multaq ® 24 274 14 312 41 295 11 347 43 296 11 350 Lovenox ® 656 30 665 1,351 730 33 596 1,359 870 38 557 1,465 Plavix ® 129 10 777 916 142 — 1,192 1,334 147 — 1,293 1,440 Generics 100 161 671 932 139 152 783 1,074 568 124 798 1,490 Specialty Care 2,314 6,766 1,874 10,954 1,988 5,532 1,643 9,163 2,004 4,387 1,878 8,269 of which Aubagio ® 473 1,448 124 2,045 414 1,351 114 1,879 385 1,157 105 1,647 Cerezyme ® 249 177 264 690 259 184 265 708 270 174 267 711 Myozyme ® / Lumizyme ® 389 359 200 948 388 331 199 918 374 284 182 840 Fabrazyme ® 200 406 211 817 185 410 218 813 175 383 197 755 Eloctate ® — 445 193 638 — 517 167 684 — 500 108 608 Jevtana ® 187 246 103 536 170 212 102 484 158 179 85 422 Dupixent ® 386 2,808 340 3,534 204 1,669 201 2,074 75 660 53 788 Consumer Healthcare 1,359 1,071 1,964 4,394 1,434 1,105 2,156 4,695 1,403 1,066 2,191 4,660 of which Allergy, Cough & Cold 305 361 430 1,096 364 323 502 1,189 347 303 474 1,124 Pain 539 181 505 1,225 543 185 552 1,280 521 165 568 1,254 Digestive 319 86 453 858 326 157 502 985 314 195 477 986 Nutritionals 127 43 441 611 130 38 453 621 125 37 513 675 Vaccines 973 2,759 2,241 5,973 851 2,733 2,147 5,731 728 2,577 1,813 5,118 of which Polio/Pertussis/ 331 412 1,363 2,106 315 380 1,251 1,946 296 397 1,056 1,749 Influenza Vaccines 441 1,575 456 2,472 230 1,289 372 1,891 177 1,233 298 1,708 Total net sales 9,151 13,465 13,425 36,041 9,082 12,756 14,288 36,126 9,434 11,540 13,489 34,463 (a) The analysis of net sales for 2019 has been restated to align on Sanofi's new management reporting structure, and to reflect the reallocation of certain countries between geographical regions.
Schedule of Segment Results	The table below sets forth Sanofi’s segment results for the years ended December 31, 2020, December 31, 2019 and December 31, 2018: 2020 (a) (€ million) Pharmaceuticals Consumer Vaccines Other Total Net sales 25,674 4,394 5,973 — 36,041 Other revenues 128 59 1,141 — 1,328 Cost of sales (7,025) (1,506) (3,328) (245) (12,104) Research and development expenses (4,331) (136) (692) (370) (5,529) Selling and general expenses (5,097) (1,450) (822) (2,021) (9,390) Other operating income and expenses (488) 54 2 (130) (562) Share of profit/(loss) from investments accounted for using the equity method 5 9 2 — 16 Net income attributable to non-controlling interests (33) (5) — — (38) Business operating income 8,833 1,419 2,276 (2,766) 9,762 (a) " Business operating income" no longer includes Sanofi’s equity-accounted share of Regeneron’s net profits (see definition above, and Note D.1.). 2019 (a) (€ million) Pharmaceuticals Consumer Vaccines Other Total Net sales 25,700 4,695 5,731 — 36,126 Other revenues 173 57 1,275 — 1,505 Cost of sales (6,750) (1,599) (3,372) (252) (11,973) Research and development expenses (4,850) (149) (639) (380) (6,018) Selling and general expenses (5,442) (1,529) (823) (2,089) (9,883) Other operating income and expenses (625) 193 — 50 (382) Share of profit/(loss) from investments accounted for using the equity method 5 (5) 9 — 9 Net income attributable to non-controlling interests (29) (6) — — (35) Business operating income 8,182 1,657 2,181 (2,671) 9,349 (a) In line with the amended management reporting structure adopted in 2020, " Business operating income" no longer includes Sanofi’s equity-accounted share of Regeneron’s net profits (see definition above, and Note D.1.). It includes the effects of IFRS 16, and the reallocation of some products from Phamaceuticals to Consumer Healthcare (immaterial impact) and the reallocation of costs previously reported in "Other" to operating segments, for a net amount of €291 million). 2018 (a) (€ million) Pharmaceuticals Consumer Vaccines Other Total Net sales 24,685 4,660 5,118 — 34,463 Other revenues 252 — 962 — 1,214 Cost of sales (6,738) (1,539) (2,854) (190) (11,321) Research and development expenses (4,572) (143) (555) (624) (5,894) Selling and general expenses (5,431) (1,534) (710) (2,156) (9,831) Other operating income and expenses (37) 101 (4) (124) (64) Share of profit/(loss) from investments accounted for using the equity method 17 1 (3) — 15 Net income attributable to non-controlling interests (96) (10) — — (106) Business operating income (a) 8,080 1,536 1,954 (3,094) 8,476 (a) " Business operating income" no longer includes Sanofi’s equity-accounted share of Regeneron’s net profits (see definition above, and Note D.1.). Due to lack of available data and the over-complex adjustments that would be required (in particular to Sanofi's reporting tools), 2018 figures have not been restated to reflect the changes arising from the new organizational structure.
Schedule of Reconciliation Between Business Operating Income for the Segments and Income Before Tax and Investments Accounted for Using the Equity Method	The table below, presented in compliance with IFRS 8, shows a reconciliation between aggregated “Business operating income” for the segments and Income before tax and investments accounted for using the equity method: (€ million) 2020 2019 2018 Business operating income (a) 9,762 9,349 8,476 Share of profit/(loss) from investments accounted for using the equity method (b) (16) (9) (15) Net income attributable to non-controlling interests (c) 38 35 106 Amortization and impairment of intangible assets (2,011) (5,750) (2,888) Fair value remeasurement of contingent consideration 124 238 117 Expenses arising from the impact of acquisitions on inventories (d) (53) (3) (114) Restructuring costs and similar items (1,064) (1,062) (1,480) Other expenses related to business combinations — — (28) Other gains and losses, and litigation (e) 136 327 502 Gain on divestment of Regeneron shares on May 29, 2020 (f) 7,225 — — Operating income 14,141 3,125 4,676 Financial expenses (390) (444) (435) Financial income 53 141 164 Income before tax and investments accounted for using the equity method 13,804 2,822 4,405 (a) "Business operating income" as presented for 2019 and 2018 has been restated to exclude Sanofi’s equity-accounted share of Regeneron’s net profits, which amounted to € 411 million in 20 19 and €408 million in 2018 (see above). In addition, "Business operating income" for 2019 has been restated to include (i) the effects of IFRS 16 and (ii) the effect of certain expenses and income being presented differently for segment reporting purposes to align on Sanofi’s new 2020 management reporting structure. (b) Excludes restructuring costs relating to investments accounted for using the equity method and expenses arising from the impact of acquisitions on investments accounted for using the equity method. For 2019 and 2018, this line has been restated to exclude any effect of equity method accounting for the investment in Regeneron following the divestment of Sanofi's entire equity interest (with the exception of the 400,000 shares retained by Sanofi) on May 29, 2020. (c) Excludes (i) restructuring costs and (ii) other adjustments attributable to non-controlling interests. (d) This line records the impact of the workdown of acquired inventories remeasured at fair value at the acquisition date. (e) For 2020, this line mainly comprises the gain on the sale of operations related to the Seprafilm ® activity to Baxter. For 2019, this line comprises a net gain, mainly arising from a settlement of litigation. For 2018, this line includes the gain on the divestment of Sanofi's European Generics business (€510 million). (f) This line includes the gain on the sale of (i) 13 million shares of Regeneron common stock in the registered public offering and (ii) the 9.8 million shares repurchased by Regeneron, but does not include the gain arising from the remeasurement of the 400,000 retained shares at market value as of May 29, 2020.
Schedule of Acquisition of Intangible Assets, Property, Plant and Equipment and Investments Accounted for Using the Equity Method by Segment	Acquisitions of intangible assets and property, plant and equipment correspond to acquisitions paid for during the period. 2020 (€ million) Pharmaceuticals Consumer Vaccines Total Investments accounted for using the equity method 154 — 47 201 Acquisitions of property, plant and equipment 755 95 404 1,254 Acquisitions of other intangible assets 532 6 322 860 2019 (€ million) Pharmaceuticals Consumer Vaccines Total Investments accounted for using the equity method (a) 205 4 40 249 Acquisitions of property, plant and equipment (b) 773 88 462 1,323 Acquisitions of other intangible assets 321 51 121 493 (a) This line has been restated to eliminate Sanofi’s equity investment in Regeneron, which had a carrying amount of €3,342 million as of December 31, 2019 (see Note D.35., "Segment Information", above) . (b) Includes the effect of restatements needed to align on Sanofi’s new 2020 management reporting structure. (€ million) 2018 Pharmaceuticals Consumer Vaccines Total Investments accounted for using the equity method (a) 297 20 30 347 Acquisitions of property, plant and equipment (b) 1,046 5 364 1,415 Acquisitions of other intangible assets 434 7 121 562 (a) This line has been restated to eliminate Sanofi’s equity investment in Regeneron, which had a carrying amount of €3,055 million as of December 31, 2018 (see Note D.35., "Segment Information", above) . (b) Due to lack of available data and the over-complex adjustments that would be required (in particular to Sanofi's reporting tools), 2018 figures have not been restated to reflect the changes arising from the new segment reporting model.
Summary of Geographical Information on Net Sales and Non-Current Assets	The geographical information on net sales provided below is based on the geographical location of the customer. In accordance with IFRS 8, the non-current assets reported below exclude right-of-use assets relating to leases as determined under IFRS 16, investments accounted for using the equity method, other non-current assets, non-current income tax assets, and deferred tax assets. 2020 (€ million) Total Europe of which North of which Other Net sales 36,041 9,151 2,223 14,060 13,465 12,830 Non-current assets: • property, plant and equipment owned 9,365 5,895 3,189 2,542 1,899 928 • goodwill 44,364 — — — — — ▪ other intangible assets 18,421 6,278 — 10,675 — 1,468 2019 (a) (€ million) Total Europe of which North of which Other Net sales (a) 36,126 9,082 2,261 13,370 12,756 13,674 Non-current assets: • property, plant and equipment owned 9,717 5,827 3,141 2,862 2,264 1,028 • goodwill 44,519 — — — — — • other intangible assets 16,572 6,941 — 7,825 — 1,806 (a) Net sales and property, plant and equipment owned for 2019 have been restated to align on the new management reporting structure, and to reflect the reallocation of certain countries between geographical regions. (€ million) 2018 (a) Total Europe of which North of which Other Net sales 34,463 9,434 2,319 12,193 11,540 12,836 Non-current assets: • property, plant and equipment owned 9,651 5,871 3,163 2,719 2,238 1,061 • goodwill 44,235 — — — — — • other intangible assets 21,889 8,058 — 11,190 — 2,641 (a) Due to lack of available data and the over-complex adjustments that would be required (in particular to Sanofi's reporting tools), 2018 figures have not been restated to reflect the changes arising from the new segment reporting model.

Principal accountants' fees a_2

Principal accountants' fees and services (Tables)	12 Months Ended
	Dec. 31, 2020
Analysis of income and expense [abstract]
Disclosure of Accountants' Fees and Services	The table below shows fees charged by those firms and member firms of their networks to Sanofi and consolidated subsidiaries in the years ended December 31, 2020 and 2019. Ernst & Young PricewaterhouseCoopers 2020 2019 2020 2019 (€ million) Amount % Amount % Amount % Amount % Audit: Statutory audit of separate and consolidated financial statements (a) 13.9 82 % 14.0 90 % 15.1 98 % 14.6 99 % Services other than statutory audit (b) 3.1 18 % 1.6 10 % 0.3 2 % 0.2 1 % Audit-related services (c) 2.5 0.9 0.2 0.2 Tax — — — — Other 0.6 0.7 0.1 — Total 17.0 100 % 15.6 100 % 15.4 100 % 14.8 100 % (a) Includes services provided by the independent auditors of the parent company and French subsidiaries: Ernst & Young €7.4 million in 2020, €7.2 million in 2019; PricewaterhouseCoopers €8.2 million in 2020, €7.3 million in 2019. (b) Services other than statutory audit provided by Ernst & Young et Autres during 2020 comprised: - work on share capital transactions and securities issues submitted to the Annual General Meeting (in extraordinary business) for approval; - additional procedures to enable reports previously signed by the firm to be incorporated by reference; - agreed-upon and audit procedures in connection with a proposed divestment; and - issuance of the Independent third party’s report on the consolidated statement of extra-financial performance. Services other than statutory audit provided by PricewaterhouseCoopers Audit during 2020 comprised: - work on share capital transactions and securities issues submitted to the Annual General Meeting (in extraordinary business) for approval; - additional procedures to enable reports previously signed by the firm to be incorporated by reference; - contractual audits, assurance engagements, agreed-upon procedures and thematic studies. (c) Includes services provided by the independent auditors of the parent company and French subsidiaries: Ernst & Young: €2.4 million in 2020, €0.8 million in 2019; PricewaterhouseCoopers €0.2 million in 2020, €0.1 million in 2019.

List of principal companies i_2

List of principal companies included in the consolidation scope during 2020 (Tables)	12 Months Ended
	Dec. 31, 2020
Interests In Other Entities [Abstract]
Summary of Principal Companies and their Country of Incorporation	: Europe Financial interest (%) as of December 31, 2020 Hoechst GmbH Germany 100.0 Sanofi-Aventis Deutschland GmbH Germany 100.0 A. Nattermann & Cie. GmbH Germany 100.0 Sanofi-Aventis GmbH Austria 100.0 Sanofi Belgium Belgium 100.0 Ablynx N.V. Belgium 100.0 Genzyme Flanders BVBA Belgium 100.0 Sanofi A/S Denmark 100.0 Sanofi-Aventis S.A. Spain 100.0 Sanofi Oy Finland 100.0 Sanofi France 100.0 Sanofi-Aventis France France 100.0 Sanofi Winthrop Industrie France 100.0 Sanofi-Aventis Recherche & Développement France 100.0 Sanofi-Aventis Groupe France 100.0 Sanofi Chimie France 100.0 Francopia France 100.0 Sanofi-Aventis Participations France 100.0 Genzyme Polyclonals SAS France 100.0 Sanofi Pasteur France 100.0 Aventis Pharma S.A. France 100.0 Sanofi Biotechnology France 100.0 Sanofi Mature IP France 100.0 Sanofi Pasteur NVL France 100.0 Sanofi Vaccine Technologies France 100.0 Sanofi Pasteur Europe France 100.0 Sanofi-Aventis A.E.B.E. Greece 100.0 Sanofi-Aventis Private Co, Ltd Hungary 99.6 Chinoin Private Co. Ltd Hungary 99.6 Carraig Insurance DAC Ireland 100.0 Sanofi-Aventis Ireland Ltd Ireland 100.0 Genzyme Ireland Limited Ireland 100.0 Sanofi Finance Ireland limited Ireland 100.0 Sanofi S.R.L. Italy 100.0 Genzyme Global Sarl Luxembourg 100.0 Sanofi-Aventis Norge AS Norway 100.0 Sanofi-Aventis Netherlands B.V. Netherlands 100.0 Genzyme Europe B.V. Netherlands 100.0 Sanofi Foreign Participations B.V. Netherlands 100.0 Sanofi-Aventis Sp. z.o.o. Poland 100.0 Sanofi Produtos Farmaceuticos Lda Portugal 100.0 Sanofi-Aventis, s.r.o. Czech Republic 100.0 Sanofi Romania SRL Romania 100.0 Sanofi-Aventis UK Holdings Limited United Kingdom 100.0 Genzyme Limited United Kingdom 100.0 Aventis Pharma Limited United Kingdom 100.0 AO Sanofi Russia Russia 100.0 sanofi-aventis Slovakia s.r.o. Slovakia 100.0 Sanofi AB Sweden 100.0 Sanofi-Aventis (Suisse) SA Switzerland 100.0 Sanofi Ilac Sanayi ve Ticaret A.S. Turkey 100.0 Sanofi Pasteur Asi Ticaret A.S. Turkey 100.0 Europe Financial interest (%) as of December 31, 2020 Sanofi Saglik Urunleri Limited Sirketi Turkey 100.0 Limited Liability Company Sanofi-Aventis Ukraine Ukraine 100.0 United States Financial interest (%) as of December 31, 2020 Genzyme Therapeutic Products Limited Partnership United States 100.0 Aventis Inc. United States 100.0 Sanofi US Corporation United States 100.0 Synthorx, Inc. United States 100.0 Sanofi US Services Inc. United States 100.0 Sanofi-Aventis U.S. LLC United States 100.0 Chattem, Inc. United States 100.0 Aventisub LLC United States 100.0 Genzyme Corporation United States 100.0 Sanofi Pasteur Inc. United States 100.0 VaxServe, Inc. United States 100.0 Bioverativ Inc. United States 100.0 Bioverativ U.S.LLC United States 100.0 Bioverativ Therapeutics Inc. United States 100.0 Sanofi Pharmaceuticals Holding Partnership United States 100.0 Principia Biopharma Inc. United States 100.0 Other Countries Financial interest (%) as of December 31, 2020 Sanofi-Aventis South Africa (Pty) Ltd South Africa 100.0 Sanofi-Aventis Algérie Algeria 100.0 Sanofi Arabia Trading Company Limited Saudi Arabia 75.0 Sanofi-Aventis Argentina S.A. Argentina 100.0 Genzyme de Argentina S.A. Argentina 100.0 Sanofi-Aventis Healthcare Pty Ltd Australia 100.0 Sanofi-Aventis Australia Pty Ltd Australia 100.0 Sanofi Medley Farmaceutica Ltda Brazil 100.0 Sanofi-Aventis Canada Inc. Canada 100.0 Sanofi Pasteur Limited Canada 100.0 Sanofi (Hangzhou) Pharmaceuticals Co., Ltd China 100.0 Sanofi (China) Investment Co., Ltd China 100.0 Sanofi (Beijing) Pharmaceuticals Co.Ltd China 100.0 Sanofi Pasteur Biologies Co., Ltd China 100.0 Shenzhen Sanofi pasteur Biological Products Co, Ltd China 100.0 Genfar S.A. Colombia 100.0 Sanofi-Aventis de Colombia S.A. Colombia 100.0 Sanofi-Aventis Korea Co. Ltd South Korea 100.0 Sanofi Pasteur Ltd South Korea 100.0 Sanofi-Aventis Gulf FZE United Arab Emirates 100.0 Sanofi-Aventis del Ecuador S.A. Ecuador 100.0 Sanofi Egypt Egypt 99.8 Sanofi-Aventis Hong-Kong Limited Hong Kong 100.0 Sanofi-Synthelabo (India) Private Ltd India 100.0 Sanofi India Limited India 60.4 Sanofi Healthcare India Private Limited India 99.9 PT Aventis Pharma Indonesia 80.0 Sanofi-Aventis Israël Ltd Israel 100.0 Sanofi K.K. Japan 100.0 SSP Co.,Ltd Japan 100.0 Sanofi Nichi-Iko K.K. Japan 51.0 Sanofi-Aventis (Malaysia) SDN. BHD. Malaysia 100.0 Sanofi-Aventis Maroc Morocco 100.0 Sanofi-Aventis de Mexico S.A. de C.V. Mexico 100.0 Sanofi-Aventis Winthrop S.A. de C.V. Mexico 100.0 Sanofi Pasteur S.A. de C.V. Mexico 100.0 Sanofi-Aventis Pakistan Limited Pakistan 52.9 Sanofi-Aventis de Panama S.A. Panama 100.0 Sanofi-Aventis del Peru S.A. Peru 100.0 sanofi-aventis Puerto Rico Inc Puerto Rico 100.0 Sanofi-Aventis Philippines Inc. Philippines 100.0 Sanofi-Aventis Singapore Pte. Ltd Singapore 100.0 Aventis Pharma (Manufacturing) Pte. Ltd Singapore 100.0 Sanofi Taiwan Co., Ltd Taiwan 100.0 Sanofi-Aventis (Thailand) Ltd Thailand 100.0 Sanofi-Aventis de Venezuela S.A. Venezuela 100.0 Sanofi-aventis Vietnam Company Limited Vietnam 100.0 Shanghai Rongheng Pharmaceutical Co, Ltd China 100.0 Sanofi Vietnam Shareholding Company Limited Vietnam 85.0 Azteca Vacunas, S.A. de C.V. Mexico 100.0
Summary of Principal Investments Accounted for Using the Equity Method	Financial interest (%) as of December 31, 2020 GlaxoSmithKline Consumer Healthcare, L.P. United States 11.7 Infraserv GmbH & Co. Höchst KG Germany 31.2 Maphar Morocco 48.3 MCM Vaccine B.V. Netherlands 50.0 MSP Vaccine Company (formerly MCM company) United States 50.0

Basis of preparation - Addition

Basis of preparation - Additional Information (Details)	Dec. 31, 2020
Lebanon
Disclosure of initial application of standards or interpretations [line items]
Cumulative inflation rate over three years	100.00%
Argentina
Disclosure of initial application of standards or interpretations [line items]
Cumulative inflation rate over three years	100.00%

Summary of significant accoun_4

Summary of significant accounting policies - Other Intangible Assets not Acquired in Business Combination (Details) - Software	12 Months Ended
	Dec. 31, 2020
Bottom of range
Disclosure of detailed information about intangible assets [line items]
Intangible asset, useful lives	3 years
Top of range
Disclosure of detailed information about intangible assets [line items]
Intangible asset, useful lives	5 years

Summary of significant accoun_5

Summary of significant accounting policies - Summary of Useful Lives of Property Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
Bottom of range | Buildings
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	15 years
Bottom of range | Fixtures
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	10 years
Bottom of range | Machinery and equipment
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	5 years
Bottom of range | Other
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	3 years
Top of range | Buildings
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	40 years
Top of range | Fixtures
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	20 years
Top of range | Machinery and equipment
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	15 years
Top of range | Other
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives or depreciation rates, property, plant and equipment	15 years

Summary of significant accoun_6

Summary of significant accounting policies - Treasury Shares (Details)	12 Months Ended
	Dec. 31, 2020EUR (€)
Corporate Information And Statement Of IFRS Compliance [Abstract]
Gain (loss) recognized on purchase of treasury shares	€ 0
Gain (loss) recognized on sale of treasury shares	0
Gain (loss) recognized on impairment of treasury shares	0
Gain (loss) recognized on cancellation of treasury shares	€ 0

Summary of significant accoun_7

Summary of significant accounting policies - Provision for Risks (Details)	12 Months Ended
	Dec. 31, 2020EUR (€)
Corporate Information And Statement Of IFRS Compliance [Abstract]
Provisions recorded for future operating losses	€ 0

Summary of significant accoun_8

Summary of significant accounting policies - Income Tax Expense (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of income taxes [line items]
Deferred tax expense	€ (99,000,000)	€ (1,753,000,000)	€ (731,000,000)
Elimination of inter-segment amounts
Disclosure of income taxes [line items]
Deferred tax expense	0
Temporary differences subject to GILTI
Disclosure of income taxes [line items]
Deferred tax expense	€ 0

Summary of significant accoun_9

Summary of significant accounting policies - Share-Based Payment (Details)	Apr. 30, 2019	May 02, 2018	Dec. 31, 2020
Share based payment plans [line items]
Award vesting period	4 years	4 years
Stock option plans
Share based payment plans [line items]
Option vesting period			4 years
Restricted share plans
Share based payment plans [line items]
Award vesting period			3 years

Summary of significant accou_10

Summary of significant accounting policies - Segment Information (Details)	12 Months Ended
	Dec. 31, 2020segment
Corporate Information And Statement Of IFRS Compliance [Abstract]
Number of operating segments	3

Principal alliances - Antibodie

Principal alliances - Antibodies Collaboration Agreement with Regeneron Pharmaceuticals, Inc. (Details) € in Millions, $ in Millions	Apr. 01, 2020	Dec. 31, 2020EUR (€)	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)	Dec. 31, 2017USD ($)
Disclosure of detailed information about Principal Alliances [Line Items]
Percentage of profits and losses arising from commercial operations		50.00%	50.00%
Net sales | €		€ 36,041			€ 36,126	€ 34,463
Acquisitions of property, plant and equipment and intangible assets | €		€ 2,114			€ 1,816	€ 1,977
Antibodies collaboration agreement | Outside the United States
Disclosure of detailed information about Principal Alliances [Line Items]
Net sales				$ 1,000
Antibodies collaboration agreement | Outside the United States | Bottom of range
Disclosure of detailed information about Principal Alliances [Line Items]
Percentage of profits and losses arising from commercial operations		55.00%	55.00%
Antibodies collaboration agreement | Outside the United States | Top of range
Disclosure of detailed information about Principal Alliances [Line Items]
Percentage of profits and losses arising from commercial operations		65.00%	65.00%
Regeneron Pharmaceuticals, INC | Antibodies collaboration agreement
Disclosure of detailed information about Principal Alliances [Line Items]
Maximum funding of the discovery and pre-clinical development of antibodies							$ 160
Phase III costs, responsibility percentage		80.00%	80.00%
Phase III costs, responsibility percentage for Regeneron		20.00%	20.00%
Maximum additional profit-share, in percentage of Regeneron's quarterly profit		10.00%	10.00%
Percentage of cumulative development costs reimbursed		50.00%	50.00%
Period before scheduled launch date		24 months	24 months
Percentage of losses borne by Sanofi		55.00%	55.00%
Contingent sales milestone receivable			$ 250
Acquisitions of property, plant and equipment and intangible assets			$ 50
Regeneron Pharmaceuticals, INC | Antibodies collaboration agreement | Outside the United States
Disclosure of detailed information about Principal Alliances [Line Items]
Royalty expense, percentage	5.00%

Principal alliances - Immuno-On

Principal alliances - Immuno-Oncology Agreement with Regeneron Pharmaceuticals, Inc. (Details) - USD ($)	Jul. 01, 2015	Dec. 31, 2020	Dec. 31, 2015
Development of cemiplimab (REGN2810) | Regeneron Pharmaceuticals, INC
Disclosure of Principal Alliances [Line Items]
Maximum additional funding for PD1 - part of each company			$ 820,000,000
Agreement amendment | Development of cemiplimab (REGN2810) | Regeneron Pharmaceuticals, INC
Disclosure of Principal Alliances [Line Items]
Prior development budget in total			$ 1,640,000,000
Contractual agreement for anti-programmed cell death protein1			5000.00%
Regeneron Pharmaceuticals, INC | Development of cemiplimab (REGN2810)
Disclosure of Principal Alliances [Line Items]
PD1 Sales Milestone payment from Sanofi			$ 375,000,000
Minimum sales of PD1 in 12-month period to be achieved for milestone payment			$ 2,000,000,000
Regeneron Pharmaceuticals, INC | Immuno-oncology collaboration agreement
Disclosure of Principal Alliances [Line Items]
Upfront payments	$ 640,000,000
Future development expense	$ 1,000,000,000
Percentage of future development expense - Regeneron part	25.00%
Future development expense - Regeneron part	$ 250,000,000
Percentage of future development expense - Sanofi part	75.00%
Future development expense - Sanofi part	$ 750,000,000
Reallocation of the development expenses to IO from Antibodies Collaboration Agreement	$ 75,000,000
Spread period for the reallocation of the development expenses to IO from Antibodies Collaboration Agreement	3 years
Annual contribution for antibody discovery collaboration	$ 160,000,000
Payments due under original Immuno-oncology Agreement		$ 462,000,000
Regeneron Pharmaceuticals, INC | Antibodies collaboration agreement
Disclosure of Principal Alliances [Line Items]
Percentage of cumulative development costs reimbursed		50.00%
Maximum additional profit-share, in percentage of Regeneron's quarterly profit		10.00%

Principal alliances - Investmen

Principal alliances - Investment Agreement with Regerneron Pharmaceuticals, Inc. (Details) - shares	May 29, 2020	Jan. 31, 2018	Jan. 31, 2014	Dec. 31, 2020	Dec. 31, 2019
Regeneron
Disclosure of detailed information about Principal Alliances [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	22,800,000
Non-current financial assets, number of shares (in shares)	400,000			279,766
Public Offering | Regeneron
Disclosure of detailed information about Principal Alliances [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	13,000,000			120,234	530,172
2018 Letter Agreement | Regeneron
Disclosure of detailed information about Principal Alliances [Line Items]
Aggregate number of Regeneron shares that could be sold for cemiplimab and dupilimab funding costs (in shares)				1,400,000
Regeneron Pharmaceuticals, INC | 2014 Amended Investment Agreement
Disclosure of detailed information about Principal Alliances [Line Items]
Maximum ownership percentage allowed to acquire			30.00%
Regeneron Pharmaceuticals, INC | Investment agreement
Disclosure of detailed information about Principal Alliances [Line Items]
Threshold ownership percentage of capital stock to designate an independent director			20.00%
Maximum percentage of capital stock acquired			25.00%
Regeneron Pharmaceuticals, INC | 2018 Letter Agreement
Disclosure of detailed information about Principal Alliances [Line Items]
Maximum percentage of capital stock acquired		25.00%
Aggregate number of Regeneron shares that could be sold for cemiplimab and dupilimab funding costs (in shares)		1,400,000

Principal alliances - Bristol-M

Principal alliances - Bristol-Myers Squibb (BMS) (Details) $ in Millions	Feb. 28, 2020USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2020product
Entities and companies managed by Bristol Mayers Squibb
Disclosure of Principal Alliances [Line Items]
Equity interest	50.10%
Purchase of interests in investments accounted for using equity method	$ 12
Bristol-Myers Squibb
Disclosure of Principal Alliances [Line Items]
Number of leading products jointly developed | product			2
Royalty payment to be paid by Sanofi		$ 200

Changes in the scope of conso_3

Changes in the scope of consolidation in 2020 - Additional Information (Details) $ / shares in Units, € in Millions, $ in Millions		May 29, 2020EUR (€)shares	May 29, 2020USD ($)shares	Feb. 14, 2020EUR (€)	Dec. 31, 2020EUR (€)shares	Dec. 31, 2020EUR (€)shares		Dec. 31, 2019EUR (€)shares		Dec. 31, 2018EUR (€)		Sep. 28, 2020EUR (€)	Sep. 28, 2020$ / shares	May 29, 2020$ / shares	Jan. 23, 2020EUR (€)	Jan. 23, 2020$ / shares	Jan. 31, 2018shares
Disclosure of detailed information about business combination [line items]
Net cash flow on acquisition	[1]					€ (5,336)		€ (488)		€ (12,857)
Investments accounted for using the equity method					€ 201	201		3,591		3,402
Gains on disposals of investments						7,382		0		0
Proceeds from sales of investments accounted for using equity method						10,370		0		0
Gains on disposal of non-current assets, net of tax				€ 129
Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax				€ 311		€ 918	[2]	€ 1,224	[2]	€ 2,163	[2]
2018 Letter Agreement | Regeneron Pharmaceuticals, INC
Disclosure of detailed information about business combination [line items]
Aggregate number of Regeneron shares that could be sold for cemiplimab and dupilimab funding costs (in shares) | shares																	1,400,000
Regeneron
Disclosure of detailed information about business combination [line items]
Non-current financial assets, number of shares (in shares) | shares		400,000			279,766	279,766
Sale of stock, number of shares issued in transaction (in shares) | shares		22,800,000	22,800,000
Proceeds from sales of investments accounted for using equity method, before transaction costs		€ 10,575
Investments accounted for using the equity method		3,668
Gains on disposals of investments		7,382
Transaction-related costs		64
Gains (losses) on remeasuring available-for-sale financial assets, net of tax		157
Quoted stock market price per share (in USD per share) | $ / shares														$ 612.81
Fair value through other comprehensive income		221			€ 111	€ 111
Tax expense on disposal of investment		502
Proceeds from sales of investments accounted for using equity method		10,370
Regeneron | Reserve of exchange differences on translation
Disclosure of detailed information about business combination [line items]
Gains on disposals of investments		€ 318
Regeneron | Public Offering
Disclosure of detailed information about business combination [line items]
Sale of stock, number of shares issued in transaction (in shares) | shares		13,000,000	13,000,000		120,234			530,172
Sale of stock, price per share (in USD per share) | $ / shares														515
Proceeds from sales of investments accounted for using equity method, before transaction costs | $			$ 6,703
Regeneron | Public Offering | Sanofi SA
Disclosure of detailed information about business combination [line items]
Sale of stock, number of shares issued in transaction (in shares) | shares		10,600,000	10,600,000
Regeneron | Regeneron Pharmaceuticals, INC | Repurchase From The Counterpart
Disclosure of detailed information about business combination [line items]
Sale of stock, price per share (in USD per share) | $ / shares														$ 509.85
Proceeds from sales of investments accounted for using equity method, before transaction costs | $			$ 5,000
Shares agreement, sale of stock, number of shares issued in transaction (in shares) | shares		9,800,000
Regeneron | 2018 Letter Agreement
Disclosure of detailed information about business combination [line items]
Aggregate number of Regeneron shares that could be sold for cemiplimab and dupilimab funding costs (in shares) | shares					1,400,000	1,400,000
Sale of stock, number of shares issued in transaction, shares agreement (in shares) | shares					779,320	779,320
Principia
Disclosure of detailed information about business combination [line items]
Purchase price (in USD per share) | $ / shares													$ 100
Goodwill												€ 913
Negative contribution to consolidated net income						€ 45
Acquisition costs, period cost						(13)
Net cash flow on acquisition						(2,972)
Synthorx
Disclosure of detailed information about business combination [line items]
Purchase price (in USD per share) | $ / shares																$ 68
Goodwill															€ 930
Negative contribution to consolidated net income						106
Acquisition costs, period cost								€ (8)
Net cash flow on acquisition						€ (2,245)
[1]	This line item includes payments made in respect of contingent consideration identified and recognized as a liability in business combinations.
[2]	This line item includes proceeds from disposals of investments in consolidated entities and of other non-current financial assets. For 2020, it includes the sale to Baxter of operations relating to Seprafilm ® for a selling price before taxes of €311 million and the divestment of certain established prescription products for €97 million before taxes, plus contingent consideration of €167 million before taxes relating to a past divestment. For 2019, it includes the proceeds from the divestments of Sanofi's entire equity interests in Alnylam for €706 million and in MyoKardia for €118 million (see Note D.7.1.). For 2018, it includes an amount of €1,598 million (net of transaction costs) for the divestment of the European Generics business (see Note D.2.2.).

Changes in the scope of conso_4

Changes in the scope of consolidation in 2020 - Summary of Provisional Purchase Price Allocation (Details) - Principia € in Millions	Sep. 28, 2020EUR (€)
Disclosure of detailed information about business combination [line items]
Intangible assets other than goodwill	€ 2,534
Other current and non-current assets and liabilities	(38)
Cash and cash equivalents	186
Net deferred tax position	(437)
Net assets at acquisition date	2,245
Goodwill	913
Purchase price	€ 3,158

Changes in the scope of conso_5

Changes in the scope of consolidation in 2020 - Summary of Purchase Price Allocation (Details) - Synthorx € in Millions	Jan. 23, 2020EUR (€)
Disclosure of detailed information about business combination [line items]
Intangible assets other than goodwill	€ 1,549
Other current and non-current assets and liabilities	36
Net deferred tax position	(269)
Net assets at acquisition date	1,316
Goodwill	930
Purchase price	€ 2,246

Principal changes in the scop_3

Principal changes in the scope of consolidation in 2019 and 2018 - Additional Information (Details) € in Millions, $ in Billions

May 29, 2020shares

Feb. 14, 2020EUR (€)

Sep. 30, 2018EUR (€)

May 14, 2018EUR (€)

Dec. 31, 2020EUR (€)

Dec. 31, 2019EUR (€)

Dec. 31, 2018EUR (€)

Mar. 08, 2018EUR (€)

Mar. 08, 2018USD ($)

Disclosure of detailed information about business combination [line items]

Gain on sale of business before taxes

€ 136

€ 327

€ 502

Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax

€ 311

€ 918

[1]

€ 1,224

[1]

€ 2,163

[1]

Regeneron

Disclosure of detailed information about business combination [line items]

Sale of stock, number of shares issued in transaction (in shares) | shares

22,800,000

Bioverativ

Disclosure of detailed information about business combination [line items]

Purchase price

€ 9,354

$ 11.6

Goodwill

€ 2,676

Sanofi Belgium

Disclosure of detailed information about business combination [line items]

Purchase price

€ 3,897

Goodwill

€ 1,360

Financial interest in principal fully consolidated companies

95.60%

European Generics Business

Disclosure of detailed information about business combination [line items]

Gain on sale of business before taxes

€ 510

Proceeds from disposals of property, plant and equipment, intangible assets and other non-current assets, net of tax

€ 1,598

[1]

This line item includes proceeds from disposals of investments in consolidated entities and of other non-current financial assets. For 2020, it includes the sale to Baxter of operations relating to Seprafilm ® for a selling price before taxes of €311 million and the divestment of certain established prescription products for €97 million before taxes, plus contingent consideration of €167 million before taxes relating to a past divestment. For 2019, it includes the proceeds from the divestments of Sanofi's entire equity interests in Alnylam for €706 million and in MyoKardia for €118 million (see Note D.7.1.). For 2018, it includes an amount of €1,598 million (net of transaction costs) for the divestment of the European Generics business (see Note D.2.2.).

Principal changes in the scop_4

Principal changes in the scope of consolidation in 2019 and 2018 - Summary of Changes in Equity Interest Held (Details) - Regeneron Pharmaceuticals, INC - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Share Capital Reserves and Other Equity Interest [Line Items]
Carrying amount	€ 3,342	€ 3,055
Equity interest	21.20%	21.70%
Acquisitions of shares	€ 0	€ 0
Disposals of shares	€ 33	€ 24

Principal changes in the scop_5

Principal changes in the scope of consolidation in 2019 and 2018 - Summary of Purchase Price Allocation (Details) € in Millions, $ in Billions	May 14, 2018EUR (€)	Mar. 08, 2018EUR (€)	Mar. 08, 2018USD ($)
Bioverativ
Disclosure of detailed information about business combination [line items]
Intangible assets other than goodwill		€ 8,113
Inventories		145
Cash and cash equivalents		422
Other current and non-current assets and liabilities		16
True North Therapeutics contingent consideration liability		(226)
Net deferred tax position		(1,792)
Net assets at acquisition date		6,678
Goodwill		2,676
Purchase price		€ 9,354	$ 11.6
Sanofi Belgium
Disclosure of detailed information about business combination [line items]
Intangible assets other than goodwill	€ 2,409
Cash and cash equivalents	258
Other current and non-current assets and liabilities	131
Net deferred tax position	(261)
Net assets at acquisition date	2,537
Goodwill	1,360
Purchase price	€ 3,897

Principal changes in the scop_6

Principal changes in the scope of consolidation in 2019 and 2018 - Summary of Assets and Liabilities Divested (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Assets
Property, plant and equipment	€ 9,365	€ 9,717	€ 9,651
Goodwill	44,364	44,519	44,235
Intangible assets other than goodwill	18,421	16,572	21,889
Other non-current assets	2,734	2,503	2,815
Deferred tax assets	4,212	5,434	4,613
Inventories	8,352	7,994	7,477
Accounts receivable	7,491	7,937	7,260
Other current assets	2,737	2,445	2,023
Cash and cash equivalents	13,915	9,427	6,925		€ 10,315
Total assets	114,529	112,736	111,408
Liabilities
Non-current provisions	7,536	7,641	7,206
Deferred tax liabilities	1,770	2,294	3,414
Other current liabilities	19,248	20,381	17,376
Short-term debt and current portion of long-term debt	€ 2,767	€ 4,554	€ 2,633
Disposal groups classified as held for sale | European Generics Business
Assets
Property, plant and equipment				€ 120
Goodwill				913
Intangible assets other than goodwill				75
Other non-current assets				1
Deferred tax assets				83
Inventories				129
Accounts receivable				107
Other current assets				40
Cash and cash equivalents				122
Total assets				1,590
Liabilities
Non-current provisions				27
Deferred tax liabilities				14
Accounts payable				91
Other current liabilities				216
Short-term debt and current portion of long-term debt				46
Total liabilities				€ 394

Property, plant and equipment -

Property, plant and equipment - Schedule of Property, Plant and Equipment (Including Assets Held Under Finance Leases) (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	€ 9,717	€ 9,651
Acquisitions and other increases	1,310	1,261	€ 1,459
Property, plant and equipment, ending balance	9,365	9,717	9,651
Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	23,568	22,697	21,978
Changes in scope of consolidation	10		22
Acquisitions and other increases	1,310	1,261	1,459
Disposals and other decreases	(487)	(319)	(669)
Currency translation differences	(711)	200	111
Transfers	(521)	(271)	(204)
Property, plant and equipment, ending balance	23,169	23,568	22,697
Accumulated depreciation and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	(13,851)	(13,046)	(12,399)
Depreciation expense	(1,143)	(1,137)	(1,137)
Impairment losses, net of reversals	(43)	(98)	(95)
Disposals and other decreases	460	313	526
Currency translation differences	345	(92)	(58)
Transfers	428	209	117
Property, plant and equipment, ending balance	(13,804)	(13,851)	(13,046)
Land
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	244	264
Property, plant and equipment, ending balance	226	244	264
Land | Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	255	283	318
Changes in scope of consolidation	0		0
Acquisitions and other increases	0	0	0
Disposals and other decreases	(11)	(3)	(23)
Currency translation differences	(13)	6	0
Transfers	5	(31)	(12)
Property, plant and equipment, ending balance	236	255	283
Land | Accumulated depreciation and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	(11)	(19)	(20)
Depreciation expense	0	0	0
Impairment losses, net of reversals	0	(4)	(8)
Disposals and other decreases	1	2	8
Currency translation differences	0	0	0
Transfers	0	10	1
Property, plant and equipment, ending balance	(10)	(11)	(19)
Buildings
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	3,217	3,087
Property, plant and equipment, ending balance	2,930	3,217	3,087
Buildings | Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	7,282	6,883	6,768
Changes in scope of consolidation	6		6
Acquisitions and other increases	16	10	22
Disposals and other decreases	(173)	(42)	(227)
Currency translation differences	(264)	80	57
Transfers	(39)	351	257
Property, plant and equipment, ending balance	6,828	7,282	6,883
Buildings | Accumulated depreciation and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	(4,065)	(3,796)	(3,612)
Depreciation expense	(356)	(357)	(351)
Impairment losses, net of reversals	(24)	(33)	(24)
Disposals and other decreases	168	54	170
Currency translation differences	127	(40)	(29)
Transfers	252	107	50
Property, plant and equipment, ending balance	(3,898)	(4,065)	(3,796)
Machinery and equipment
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	3,393	3,238
Property, plant and equipment, ending balance	3,335	3,393	3,238
Machinery and equipment | Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	11,053	10,468	10,145
Changes in scope of consolidation	3		11
Acquisitions and other increases	40	50	48
Disposals and other decreases	(177)	(148)	(272)
Currency translation differences	(276)	64	26
Transfers	484	619	510
Property, plant and equipment, ending balance	11,127	11,053	10,468
Machinery and equipment | Accumulated depreciation and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	(7,660)	(7,230)	(6,885)
Depreciation expense	(605)	(586)	(595)
Impairment losses, net of reversals	(12)	(4)	(40)
Disposals and other decreases	166	140	235
Currency translation differences	169	(40)	(15)
Transfers	150	60	70
Property, plant and equipment, ending balance	(7,792)	(7,660)	(7,230)
Fixtures, fittings and other
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	603	665
Property, plant and equipment, ending balance	543	603	665
Fixtures, fittings and other | Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	2,587	2,579	2,450
Changes in scope of consolidation	1		4
Acquisitions and other increases	46	56	71
Disposals and other decreases	(123)	(114)	(127)
Currency translation differences	(67)	17	17
Transfers	80	49	164
Property, plant and equipment, ending balance	2,524	2,587	2,579
Fixtures, fittings and other | Accumulated depreciation and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	(1,984)	(1,914)	(1,804)
Depreciation expense	(182)	(194)	(191)
Impairment losses, net of reversals	(7)	(2)	(11)
Disposals and other decreases	117	106	110
Currency translation differences	49	(12)	(14)
Transfers	26	32	(4)
Property, plant and equipment, ending balance	(1,981)	(1,984)	(1,914)
Property, plant and equipment in process
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	2,260	2,397
Property, plant and equipment, ending balance	2,331	2,260	2,397
Property, plant and equipment in process | Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	2,391	2,484	2,297
Changes in scope of consolidation	0		1
Acquisitions and other increases	1,208	1,145	1,318
Disposals and other decreases	(3)	(12)	(20)
Currency translation differences	(91)	33	11
Transfers	(1,051)	(1,259)	(1,123)
Property, plant and equipment, ending balance	2,454	2,391	2,484
Property, plant and equipment in process | Accumulated depreciation and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment, beginning balance	(131)	(87)	(78)
Depreciation expense	0	0	0
Impairment losses, net of reversals	0	(55)	(12)
Disposals and other decreases	8	11	3
Currency translation differences	0	0	0
Transfers	0	0	0
Property, plant and equipment, ending balance	€ (123)	€ (131)	€ (87)

Property, plant and equipment_2

Property, plant and equipment - Summary of Acquisitions and Capitalized Interest by Operating Segment (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of acquisitions of property plant and equipment by operating segments [line items]
Acquisitions	€ 1,310	€ 1,261	€ 1,459
Capitalized interest	11	14	21
Pharmaceuticals
Disclosure of acquisitions of property plant and equipment by operating segments [line items]
Acquisitions	831	846	1,014
Pharmaceuticals | Industrial facilities
Disclosure of acquisitions of property plant and equipment by operating segments [line items]
Acquisitions	634	682	769
Pharmaceuticals | Research sites
Disclosure of acquisitions of property plant and equipment by operating segments [line items]
Acquisitions	152	87	14
Pharmaceuticals | Other
Disclosure of acquisitions of property plant and equipment by operating segments [line items]
Acquisitions	45	77	231
Vaccines
Disclosure of acquisitions of property plant and equipment by operating segments [line items]
Acquisitions	384	405	440
Consumer Healthcare
Disclosure of acquisitions of property plant and equipment by operating segments [line items]
Acquisitions	€ 95	€ 10	€ 5

Property, plant and equipment_3

Property, plant and equipment - Summary of Off Balance Sheet Commitments Relating to Property, Plant and Equipment (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, plant and equipment [abstract]
Firm orders of property, plant and equipment	€ 708	€ 398	€ 535
Property, plant and equipment pledged as security for liabilities	€ 0	€ 107	€ 123

Property, plant and equipment_4

Property, plant and equipment - Summary of Impairment Losses Recognised in Property, Plant and Equipment (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, plant and equipment [abstract]
Net impairment losses on property, plant and equipment	€ 43	€ 98	€ 94

Property, plant and equipment_5

Property, plant and equipment - Schedule of Amounts for Items of Property, Plant and Equipment Held under Finance Leases (Details) € in Millions	Dec. 31, 2018EUR (€)
Disclosure of detailed information about property, plant and equipment [line items]
Recognised finance lease as assets	€ 23
Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Recognised finance lease as assets	87
Accumulated depreciation and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Recognised finance lease as assets	(64)
Buildings | Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Recognised finance lease as assets	73
Other property, plant and equipment | Gross value
Disclosure of detailed information about property, plant and equipment [line items]
Recognised finance lease as assets	€ 14

Property, plant and equipment_6

Property, plant and equipment - Summary of Future Minimum Lease Payments Due Under Finance Lease (Details) € in Millions	Dec. 31, 2018EUR (€)
Property, plant and equipment [abstract]
Future minimum lease payments due under finance leases	€ 25
Future minimum lease payments due under finance leases of which interest	€ 3

Property, plant and equipment_7

Property, plant and equipment - Summary of Property, Plant and Equipment Leased (Details) - EUR (€) € in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2020		Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Right-of-use assets at beginning of period	[1]	€ 1,300		€ 0
Right-of-use assets at end of period	[1]	1,198		1,300
Right-of-use assets		1,198	[1]	0	[1]	€ 1,198	[1]	€ 1,300	[1]	€ 1,431	€ 0	[1]
Current and non-current lease liabilities						1,163		1,248
IFRS 16
Disclosure of detailed information about property, plant and equipment [line items]
Right-of-use assets at beginning of period				1,431
Right-of-use assets				1,431							1,431
Current and non-current lease liabilities											1,346
Increase (decrease) in provisions and other liabilities current and noncurrent											73
Gross carrying amount
Disclosure of detailed information about property, plant and equipment [line items]
Right-of-use assets at beginning of period		1,583		1,439
Acquisitions and other increases		340		157
Disposals and other decreases		(121)		(31)
Currency translation differences		(85)		18
Changes in scope of consolidation		15
Transfers		(21)
Right-of-use assets at end of period		1,711		1,583
Right-of-use assets		1,711		1,583		1,711		1,583			1,439
Accumulated depreciation and amortisation
Disclosure of detailed information about property, plant and equipment [line items]
Right-of-use assets at beginning of period		(283)		(8)
Disposals and other decreases		44		7
Currency translation differences		22
Transfers		3
Depreciation and amortization expense		(299)		(282)
Right-of-use assets at end of period		(513)		(283)
Changes in scope of consolidation		31
Right-of-use assets		€ (513)		€ (283)		€ (513)		€ (283)			€ (8)
[1]	Includes the effects of first-time application of IFRS 16 on leases using the modified retrospective approach, effective January 1, 2019.

Property, plant and equipment_8

Property, plant and equipment - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Expense relating to short-term leases and low value assets	€ 27	€ 50
Cash outflow for leases, excluding short-term leases	€ 269	€ 302
Rental expense			€ 345
Land and buildings
Disclosure of detailed information about property, plant and equipment [line items]
Leased assets, percentage	92.00%
Vehicles
Disclosure of detailed information about property, plant and equipment [line items]
Leased assets, percentage	8.00%

Goodwill and other intangible_3

Goodwill and other intangible assets - Schedule of Movements in Goodwill (Details) - Goodwill - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of reconciliation of changes in goodwill [line items]
Beginning balance	€ 44,519	€ 44,235	€ 40,264
Acquisitions during the period	1,843	0	4,039
Other movements during the period(a)	(75)	(244)	(1,006)
Currency translation differences	(1,923)	528	938
Ending balance	€ 44,364	€ 44,519	€ 44,235

Goodwill and other intangible_4

Goodwill and other intangible assets - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Sep. 28, 2020	Jan. 23, 2020	Dec. 31, 2019	Dec. 31, 2018	May 14, 2018	Mar. 08, 2018
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	€ 44,364			€ 44,519	€ 44,235
Intangible assets other than goodwill	18,421			16,572	21,889
Marketed products
Disclosure of reconciliation of changes in goodwill [line items]
Intangible assets other than goodwill	€ 11,400			13,300	15,500
Useful life measured as period of time, intangible assets other than goodwill	10 years
Concentration risk percentage	91.00%
Technological Platforms
Disclosure of reconciliation of changes in goodwill [line items]
Intangible assets other than goodwill	€ 200			200	200
Useful life measured as period of time, intangible assets other than goodwill	10 years
Trademarks
Disclosure of reconciliation of changes in goodwill [line items]
Intangible assets other than goodwill	€ 100			€ 100	100
Useful life measured as period of time, intangible assets other than goodwill	12 years
Acquired in Process R and D | Intangible assets excluding software
Disclosure of reconciliation of changes in goodwill [line items]
Acquired R and D starting to be amortized in the period	€ 692
Principia
Disclosure of reconciliation of changes in goodwill [line items]
Identifiable intangible assets recognised as of acquisition date		€ 2,534
Goodwill		€ 913
Synthorx
Disclosure of reconciliation of changes in goodwill [line items]
Identifiable intangible assets recognised as of acquisition date			€ 1,549
Goodwill			€ 930
Bioverativ
Disclosure of reconciliation of changes in goodwill [line items]
Identifiable intangible assets recognised as of acquisition date							€ 8,113
Goodwill							€ 2,676
Ablynx N.V.
Disclosure of reconciliation of changes in goodwill [line items]
Identifiable intangible assets recognised as of acquisition date						€ 2,409
Goodwill						€ 1,360
Immuno-oncology product Libtayo | Acquired in Process R and D
Disclosure of reconciliation of changes in goodwill [line items]
Acquired R and D starting to be amortized in the period					€ 348

Goodwill and other intangible_5

Goodwill and other intangible assets - Schedule of Movements in Other Intangible Assets (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	€ 16,572	€ 21,889
Other intangible assets, Ending balance	18,421	16,572	€ 21,889
Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	71,381	70,781	58,685
Changes in scope of consolidation	4,083		10,523
Acquisitions and other increases	849	475	634
Disposals and other decreases	(333)	(855)	(1,039)
Currency translation differences	(3,558)	985	1,985
Transfers	0	(5)	(7)
Other intangible assets, Ending balance	72,422	71,381	70,781
Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	(54,809)	(48,892)	(45,605)
Disposals and other decreases	321	697	944
Currency translation differences	2,649	(687)	(1,206)
Transfers	0	1	8
Amortization expense	(1,832)	(2,301)	(2,303)
Impairment losses, net of reversals	(330)	(3,627)	(730)
Other intangible assets, Ending balance	(54,001)	(54,809)	(48,892)
Acquired R&D
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	2,334	4,744
Other intangible assets, Ending balance	6,092	2,334	4,744
Acquired R&D | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	5,730	7,422	3,679
Changes in scope of consolidation	3,951		3,632
Acquisitions and other increases	654	272	367
Disposals and other decreases	(44)	(236)	(44)
Currency translation differences	(593)	86	218
Transfers	(98)	(1,814)	(430)
Other intangible assets, Ending balance	9,600	5,730	7,422
Acquired R&D | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	(3,396)	(2,678)	(2,204)
Disposals and other decreases	44	158	36
Currency translation differences	158	(31)	(54)
Transfers	14	2	0
Amortization expense	0	0	0
Impairment losses, net of reversals	(328)	(847)	(456)
Other intangible assets, Ending balance	(3,508)	(3,396)	(2,678)
Products, trademarks and other rights
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	13,639	16,572
Other intangible assets, Ending balance	11,729	13,639	16,572
Products, trademarks and other rights | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	63,953	61,800	53,638
Changes in scope of consolidation	132		6,889
Acquisitions and other increases	58	19	16
Disposals and other decreases	(243)	(569)	(920)
Currency translation differences	(2,926)	889	1,757
Transfers	100	1,814	420
Other intangible assets, Ending balance	61,074	63,953	61,800
Products, trademarks and other rights | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	(50,314)	(45,228)	(42,476)
Disposals and other decreases	232	488	840
Currency translation differences	2,460	(648)	(1,146)
Transfers	(14)	(2)	6
Amortization expense	(1,707)	(2,167)	(2,188)
Impairment losses, net of reversals	(2)	(2,757)	(264)
Other intangible assets, Ending balance	(49,345)	(50,314)	(45,228)
Software
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	599	573
Other intangible assets, Ending balance	600	599	573
Software | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	1,698	1,559	1,368
Changes in scope of consolidation	0		2
Acquisitions and other increases	137	184	251
Disposals and other decreases	(46)	(50)	(75)
Currency translation differences	(39)	10	10
Transfers	(2)	(5)	3
Other intangible assets, Ending balance	1,748	1,698	1,559
Software | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets, Beginning balance	(1,099)	(986)	(925)
Disposals and other decreases	45	51	68
Currency translation differences	31	(8)	(6)
Transfers	0	1	2
Amortization expense	(125)	(134)	(115)
Impairment losses, net of reversals	0	(23)	(10)
Other intangible assets, Ending balance	€ (1,148)	€ (1,099)	€ (986)

Goodwill and other intangible_6

Goodwill and other intangible assets - Detailed Information for Principal Marketed Products (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 18,421	€ 16,572	€ 21,889
Genzyme
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 1,485	2,095	2,988
Useful life measured as period of time, intangible assets other than goodwill	10 years
Remaining amortisation period of intangible assets material to entity	3 years
Genzyme | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 9,823
Genzyme | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	(8,338)
Boehringer Ingelheim Consumer Healthcare
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 2,489	2,699	3,237
Useful life measured as period of time, intangible assets other than goodwill	16 years
Remaining amortisation period of intangible assets material to entity	14 years
Boehringer Ingelheim Consumer Healthcare | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 3,687
Boehringer Ingelheim Consumer Healthcare | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	(1,198)
Aventis
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 110	219	409
Useful life measured as period of time, intangible assets other than goodwill	9 years
Remaining amortisation period of intangible assets material to entity	7 years
Aventis | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 32,474
Aventis | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	(32,364)
Chattem
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 602	711	748
Useful life measured as period of time, intangible assets other than goodwill	23 years
Remaining amortisation period of intangible assets material to entity	13 years
Chattem | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 1,192
Chattem | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	(590)
Protein Sciences
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 554	667	715
Useful life measured as period of time, intangible assets other than goodwill	13 years
Remaining amortisation period of intangible assets material to entity	10 years
Protein Sciences | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 751
Protein Sciences | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	(197)
Ablynx
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 1,861	2,029	376
Useful life measured as period of time, intangible assets other than goodwill	13 years
Remaining amortisation period of intangible assets material to entity	11 years
Ablynx | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 2,279
Ablynx | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	(418)
Bioverativ
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 3,240	3,788	6,385
Useful life measured as period of time, intangible assets other than goodwill	13 years
Remaining amortisation period of intangible assets material to entity	11 years
Bioverativ | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ 6,516
Bioverativ | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	(3,276)
Total: principal marketed products
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	10,341	€ 12,208	€ 14,858
Total: principal marketed products | Gross value
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	56,722
Total: principal marketed products | Accumulated depreciation and impairment
Disclosure of detailed information about intangible assets [line items]
Other intangible assets	€ (46,381)
Bottom of range
Disclosure of detailed information about intangible assets [line items]
Useful life measured as period of time, intangible assets other than goodwill	1 year
Top of range
Disclosure of detailed information about intangible assets [line items]
Useful life measured as period of time, intangible assets other than goodwill	25 years

Goodwill and other intangible_7

Goodwill and other intangible assets - Amortization of Softwares Recognized in Income Statement (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [line items]
Cost of sales	€ 12,157	€ 11,976	€ 11,435
Research and development expenses	5,529	6,018	5,894
Selling and general expenses	9,390	9,883	9,859
Other operating expenses	1,415	1,207	548
Total	1,681	2,146	2,170
Amortization of computer software and other rights of an industrial or operational nature
Disclosure of detailed information about intangible assets [line items]
Cost of sales	19	11	21
Research and development expenses	2	3	4
Selling and general expenses	100	114	87
Other operating expenses	4	6	3
Total	€ 125	€ 134	€ 115

Impairment of intangible asse_3

Impairment of intangible assets and property, plant and equipment - Additional Information (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of impairment loss and reversal of impairment loss [line items]
Discount rate	450.00%
Perpetual growth rate	2010.00%
Operating margin rate	940.00%
Impairment of goodwill recognized	€ 0	€ 0	€ 0
Bottom of range
Disclosure of impairment loss and reversal of impairment loss [line items]
After tax discount rates	7.25%
Top of range
Disclosure of impairment loss and reversal of impairment loss [line items]
After tax discount rates	8.25%
Cash-generating units
Disclosure of impairment loss and reversal of impairment loss [line items]
Uniform pre-tax discount rates	9.50%
Cash-generating units | CGUs
Disclosure of impairment loss and reversal of impairment loss [line items]
Uniform impairment testing percentage	7.20%
Pharmaceuticals | Goodwill
Disclosure of impairment loss and reversal of impairment loss [line items]
Perpetual growth rates applied to future cash flows	0.00%
Pharmaceuticals | Cash-generating units | CGUs
Disclosure of impairment loss and reversal of impairment loss [line items]
Rate used for Impairment of goodwill	7.25%
Pre-tax discount rates	9.50%
Consumer Healthcare | Goodwill
Disclosure of impairment loss and reversal of impairment loss [line items]
Perpetual growth rates applied to future cash flows	1.00%
Consumer Healthcare | Cash-generating units | CGUs
Disclosure of impairment loss and reversal of impairment loss [line items]
Rate used for Impairment of goodwill	7.00%
Pre-tax discount rates	8.90%
Vaccines | Goodwill
Disclosure of impairment loss and reversal of impairment loss [line items]
Perpetual growth rates applied to future cash flows	0.00%
Vaccines | Cash-generating units | CGUs
Disclosure of impairment loss and reversal of impairment loss [line items]
Rate used for Impairment of goodwill	7.25%
Pre-tax discount rates	9.70%

Impairment of intangible asse_4

Impairment of intangible assets and property, plant and equipment - Schedule of Allocation of Goodwill (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	€ 44,364	€ 44,519	€ 44,235
Pharmaceuticals
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	36,682
Consumer Healthcare
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	6,425
Vaccines
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	€ 1,257

Impairment of intangible asse_5

Impairment of intangible assets and property, plant and equipment - Summary of Net Impairment Losses of Other Intangible Assets (Details) - Other intangible assets - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of other intangible assets (excluding software)	€ 330	€ 3,604	€ 720
Marketed products
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of other intangible assets (excluding software)	2	2,757	264
Research and development
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of other intangible assets (excluding software)	328	847	454
Eloctate
Disclosure of impairment loss and reversal of impairment loss [line items]
Recognition of impairment loss		2,236
Marketed product Lemtrada
Disclosure of impairment loss and reversal of impairment loss [line items]
Recognition of impairment loss		163
Marketed product Lemtrada | USA
Disclosure of impairment loss and reversal of impairment loss [line items]
Recognition of impairment loss			183
Zantac
Disclosure of impairment loss and reversal of impairment loss [line items]
Recognition of impairment loss		352
Sotaglifozin
Disclosure of impairment loss and reversal of impairment loss [line items]
Recognition of impairment loss		275
Pharmaceuticals | Marketed products
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of other intangible assets (excluding software)	2	2,405	258
Vaccines | Marketed products
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of other intangible assets (excluding software)	0	0	6
CHC | Marketed products
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of other intangible assets (excluding software)	0	352	0
Other
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of other intangible assets (excluding software)	€ 0	€ 0	€ 2

Investments accounted for usi_3

Investments accounted for using the equity method - Summary of Investments in Associates and Joint Ventures (Details) € in Millions, $ in Millions	May 29, 2020shares	Feb. 28, 2020USD ($)	Dec. 31, 2020EUR (€)shares	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Disclosure of transactions between related parties [line items]
Investments in subsidiaries, joint ventures and associates			€ 201	€ 3,591	€ 3,402
BioAtrium AG
Disclosure of transactions between related parties [line items]
Proportion of voting rights held in joint venture			31.20%
Investments in joint ventures			€ 72	70	73
Other investments
Disclosure of transactions between related parties [line items]
Proportion of voting rights held in joint venture			0.00%
Investments in joint ventures			€ 129	142	126
Regeneron Pharmaceuticals, INC
Disclosure of transactions between related parties [line items]
% interest			0.00%
Investments in associates			€ 0	3,342	3,055
Onduo LLC
Disclosure of transactions between related parties [line items]
% interest			19.90%
Investments in associates			€ 0	0	108
Entities and companies managed by Bristol Mayers Squibb
Disclosure of transactions between related parties [line items]
% interest			100.00%
Investments in associates			€ 0	€ 37	€ 40
Equity interest		50.10%
Purchase of interests in investments accounted for using equity method | $		$ 12
Regeneron
Disclosure of transactions between related parties [line items]
% interest				21.00%	22.00%
Investments in associates				€ 3,342	€ 3,055
Sale of stock, number of shares issued in transaction (in shares) | shares	22,800,000
Non-current financial assets, number of shares (in shares) | shares	400,000		279,766
Onduo LLC
Disclosure of transactions between related parties [line items]
% interest			19.90%	19.90%

Investments accounted for usi_4

Investments accounted for using the equity method - Summary of Share of Profit or Loss and Other Comprehensive Income of Associates and Joint Ventures (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Joint ventures
Disclosure of transactions between related parties [line items]
Share of profit/(loss) from investments accounted for using the equity method	€ 4	€ 15	€ 17
Share of other comprehensive income from investments accounted for using the equity method	8	(7)	(7)
Total	12	8	10
Associates
Disclosure of transactions between related parties [line items]
Share of profit/(loss) from investments accounted for using the equity method	355	240	482
Share of other comprehensive income from investments accounted for using the equity method	(311)	90	105
Total	€ 44	€ 330	€ 587

Investments accounted for usi_5

Investments accounted for using the equity method - Summary of Principal Transactions and Balances with Related Parties (Details) - Associates and joint ventures - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of transactions between related parties [line items]
Sales	€ 75	€ 24	€ 35
Royalties and other income	97	270	116
Accounts receivable and other receivables	50	151	89
Purchases and other expenses (including research expenses)	747	1,334	1,143
Accounts payable and other payables	€ 15	€ 342	€ 544

Investments accounted for usi_6

Investments accounted for using the equity method - Additional Information (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019
Associates and joint ventures
Disclosure of transactions between related parties [line items]
Funding commitments to associates and joint ventures	€ 0	€ 67

Investments accounted for usi_7

Investments accounted for using the equity method - Summary of Financial Statements of Regeneron, After Adjustments to Comply With IFRS But Before Fair Value Remeasurements (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	[1]
Disclosure of transactions between related parties [line items]
Net income	€ 12,350	€ 2,837	€ 4,410
Other comprehensive income for the period, net of taxes	(4,010)	650	959
Comprehensive income	8,340	3,487	5,369
Non-current assets	80,743	83,800	86,761
Total assets	114,529	112,736	111,408
Non-current liabilities	32,102	33,241	34,997
Consolidated shareholders’ equity of Regeneron	€ 63,147	59,108	59,035	€ 58,239
Regeneron
Disclosure of transactions between related parties [line items]
Net sales and other revenues		7,023	5,680
Net income		1,882	2,476
Other comprehensive income for the period, net of taxes		113	(33)
Comprehensive income		1,995	2,443
Current assets		6,858	5,621
Non-current assets		6,627	4,731
Total assets		13,485	10,352
Current liabilities		1,870	1,258
Non-current liabilities		925	772
Total liabilities		2,795	2,030
Consolidated shareholders’ equity of Regeneron		€ 10,690	€ 8,322
[1]	Includes the effects of first-time application of IFRS 15 on revenue recognition.

Investments accounted for usi_8

Investments accounted for using the equity method - Summary of Reconciliation to Carrying Amount of Investment (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]
Share of equity attributable to Sanofi	€ (58,934)	€ (58,876)	€ (63,001)
Goodwill	€ 44,519	€ 44,235	€ 44,364
Regeneron
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]
% interest	21.00%	22.00%
Share of equity attributable to Sanofi	€ 2,263	€ 1,806
Goodwill	839	858
Fair value remeasurements of assets and liabilities at the acquisition date	811	873
Other items	(571)	(482)
Carrying amount of the investment in Regeneron	€ 3,342	€ 3,055

Investments accounted for usi_9

Investments accounted for using the equity method - Summary of Market Value of Sanofi's Investment in Regeneron Based on Quoted Stock Market Price Per Share (Details) - Regeneron $ / shares in Units, € in Millions, $ in Millions	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2019EUR (€)	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2018EUR (€)
Disclosure of transactions between related parties [line items]
Quoted stock market price per share (in USD per share)	$ 375.48		$ 373.50
Market value of investment in Regeneron ($/€ million)	$ 8,767	€ 7,820	$ 8,835	€ 7,702

Other non-current assets - Summ

Other non-current assets - Summary of Other Non-current Assets (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Other Non Current Assets [Line Items]
Other financial assets at fair value through profit or loss	€ 890	€ 892	€ 733
Pre-funded pension obligations	177	155	77
Long-term prepaid expenses	92	115	126
Long-term loans and advances and other non-current receivables	537	521	464
Derivative financial instruments	24	37	19
Other non-current assets	2,734	2,503	2,815
Trading equity securities
Disclosure Of Other Non Current Assets [Line Items]
Fair value through other comprehensive income	588	380	1,037
Debt securities
Disclosure Of Other Non Current Assets [Line Items]
Fair value through other comprehensive income	€ 426	€ 403	€ 359

Other non-current assets - Addi

Other non-current assets - Additional Information (Details) € in Millions, $ in Millions	May 29, 2020EUR (€)shares	Nov. 11, 2019USD ($)	May 02, 2019EUR (€)shares	Jun. 30, 2019EUR (€)	Dec. 31, 2020EUR (€)shares	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Disclosure Of Other Non Current Assets [Line Items]
Proceeds from sales of investments accounted for using equity method					€ 10,370	€ 0	€ 0
Investments accounted for using the equity method					201	3,591	3,402
Impairment loss on financial assets					€ (44)
Regeneron
Disclosure Of Other Non Current Assets [Line Items]
Sale of stock, number of shares issued in transaction (in shares) | shares	22,800,000
Non-current financial assets, number of shares (in shares) | shares	400,000				279,766
Fair value through other comprehensive income	€ 221				€ 111
Proceeds from sales of investments accounted for using equity method	10,370
Investments accounted for using the equity method	€ 3,668
Fair value of SPMSD contingent consideration
Disclosure Of Other Non Current Assets [Line Items]
Increase in contingent consideration					2.00%
Quoted euro denominated senior bonds
Disclosure Of Other Non Current Assets [Line Items]
Debt instruments at fair value through other comprehensive income					€ 426
Senior bond
Disclosure Of Other Non Current Assets [Line Items]
Financial assets held for investments						403	359
Financial instruments held to fund deferred compensation plan
Disclosure Of Other Non Current Assets [Line Items]
Financial investments					453	442	363
Reduction of ten percent basis point in market interest rate
Disclosure Of Other Non Current Assets [Line Items]
Other comprehensive income before tax					3
Trading equity securities
Disclosure Of Other Non Current Assets [Line Items]
Fair value through other comprehensive income					588	380	1,037
Trading equity securities | Associates
Disclosure Of Other Non Current Assets [Line Items]
Fair value through other comprehensive income					357
Unquoted equity investments
Disclosure Of Other Non Current Assets [Line Items]
Investments in equity instruments designated at fair value through OCI					149	266
Unquoted equity investments | Quoted euro denominated senior bonds
Disclosure Of Other Non Current Assets [Line Items]
Exchange for financial assets held to meet obligations to employees under post-employment benefit plans					172
Quoted debt instruments
Disclosure Of Other Non Current Assets [Line Items]
Other comprehensive income before tax					1
Quoted equity securities
Disclosure Of Other Non Current Assets [Line Items]
Unrealized after-tax losses					200	(80)	(148)
SPMSD contingent consideration asset
Disclosure Of Other Non Current Assets [Line Items]
Fair value of the contingent consideration					483	492	373
Non current asset | Fair value of SPMSD contingent consideration
Disclosure Of Other Non Current Assets [Line Items]
Fair value of the contingent consideration					374	398
Unquoted debt securities not meeting the definition of equity instruments
Disclosure Of Other Non Current Assets [Line Items]
Total financial assets measured at fair value					63	52	61
Translate Bio
Disclosure Of Other Non Current Assets [Line Items]
Investments in equity instruments designated at fair value through OCI					€ 74
Investments in equity instruments designated at fair value through OCI, ownership percentage					8.00%
Alnylam Pharmaceuticals, Inc
Disclosure Of Other Non Current Assets [Line Items]
Equity investment, shares divested | shares			10,600,000
Alnylam Pharmaceuticals, Inc | Securities quoted in an active market
Disclosure Of Other Non Current Assets [Line Items]
Percentage of company capital			10.00%
Proceeds from sales of investments accounted for using equity method			€ 706			706
Investments accounted for using the equity method							671
MyoKardia, Inc | Securities quoted in an active market
Disclosure Of Other Non Current Assets [Line Items]
Proceeds from sales of investments accounted for using equity method				€ 118		118
Investments accounted for using the equity method							€ 178
Onduo LLC
Disclosure Of Other Non Current Assets [Line Items]
Investments accounted for using the equity method					€ 90	€ 104
Dividends recognised for investments in equity instruments | $		$ 122

Assets held for sale or excha_3

Assets held for sale or exchange and liabilities related to assets held for sale or exchange - Summary of Assets Held for Sale or Exchange, and Liabilities Related to Assets Held for Sale or Exchange (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Assets held for sale or exchange	€ 83	€ 325	€ 68
Liabilities related to assets held for sale or exchange	€ 32	€ 6	€ 0

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of inventories [line items]
Raw materials	€ 975	€ 1,087	€ 1,016
Work in process	4,856	4,522	4,088
Finished goods	2,521	2,385	2,373
Total	8,352	7,994	7,477
Gross value
Disclosure of inventories [line items]
Raw materials	1,051	1,163	1,099
Work in process	5,398	5,104	4,637
Finished goods	2,739	2,629	2,533
Total	9,188	8,896	8,269
Allowances
Disclosure of inventories [line items]
Raw materials	(76)	(76)	(83)
Work in process	(542)	(582)	(549)
Finished goods	(218)	(244)	(160)
Total	€ (836)	€ (902)	€ (792)

Inventories - Additional Inform

Inventories - Additional Information (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Inventories pledged as security for liabilities	€ 17	€ 15	€ 18

Accounts receivable - Summary o

Accounts receivable - Summary of Accounts Receivable (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of accounts receivable [line items]
Accounts receivable	€ 7,491	€ 7,937	€ 7,260
Gross value
Disclosure of accounts receivable [line items]
Accounts receivable	7,633	8,090	7,430
Allowances
Disclosure of accounts receivable [line items]
Accounts receivable	€ (142)	€ (153)	€ (170)

Accounts receivable - Additiona

Accounts receivable - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of accounts receivable [line items]
Impairment loss recognised in profit or loss, trade receivables	€ 30		€ 15
Reversal of impairment loss recognised in profit or loss, trade receivables		€ 5
Gross value of overdue receivables	549	642	547
Derecognized receivables	18	€ 214	€ 385
Europe
Disclosure of accounts receivable [line items]
Derecognized receivables	€ 18

Accounts receivable - Summary_2

Accounts receivable - Summary of Gross Value of Overdue Receivables (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of financial assets that are either past due or impaired [line items]
Overdue receivables gross value	€ 549	€ 642	€ 547
Less than 1 Month
Disclosure of financial assets that are either past due or impaired [line items]
Overdue receivables gross value	271	269	257
1 to 3 Months
Disclosure of financial assets that are either past due or impaired [line items]
Overdue receivables gross value	97	171	172
3 to 6 Months
Disclosure of financial assets that are either past due or impaired [line items]
Overdue receivables gross value	52	61	36
6 to 12 Months
Disclosure of financial assets that are either past due or impaired [line items]
Overdue receivables gross value	34	36	21
Greater than 12 Months
Disclosure of financial assets that are either past due or impaired [line items]
Overdue receivables gross value	€ 95	€ 105	€ 61

Other current assets (Details)

Other current assets (Details) € in Millions, $ in Millions	Dec. 31, 2020EUR (€)	Dec. 31, 2019EUR (€)	Dec. 31, 2019USD ($)	Dec. 31, 2018EUR (€)
Subclassifications of assets, liabilities and equities [abstract]
Tax receivables, other than corporate income taxes	€ 687	€ 603		€ 564
Other receivables	567	735		627
Prepaid expenses	525	493		469
Interest rate derivatives measured at fair value (see Note D.20.)	0	4		30
Currency derivatives measured at fair value (see Note D.20.)	58	184		134
Other current financial assets	900	426		199
Total	€ 2,737	€ 2,445		€ 2,023
Escrow account, settlement | $			$ 315

Financial assets and liabilit_3

Financial assets and liabilities measured at fair value - Summary of Assets and Liabilities Measured at Fair Value (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unquoted debt securities not meeting the definition of equity instruments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	€ 63	€ 52	€ 61
Level 1
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	10,022	6,263	4,771
Total financial liabilities measured at fair value	0	0	99
Level 1 | CVRs issued in connection with the acquisition of Genzyme
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	99
Level 1 | Bayer contingent purchase consideration arising from the acquisition of Genzyme
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 1 | MSD contingent consideration (European vaccines business)
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 1 | Other contingent consideration arising from business combinations
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 1 | Liabilities related to non-controlling interests
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 1 | Non-current derivatives
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 1 | Current derivatives
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 1 | Quoted equity investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	439	114	859
Level 1 | Unquoted equity investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 1 | Quoted debt securities
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	426	403	359
Level 1 | Unquoted debt securities not meeting the definition of equity instruments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 1 | Contingent consideration relating to divestments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 1 | Financial assets held to meet obligations under deferred compensation plans
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	454	442	364
Level 1 | Non-current derivatives
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 1 | Current derivatives
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 1 | Mutual fund investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	8,703	5,304	3,189
Level 2
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	82	225	183
Total financial liabilities measured at fair value	297	99	97
Level 2 | CVRs issued in connection with the acquisition of Genzyme
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 2 | Bayer contingent purchase consideration arising from the acquisition of Genzyme
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 2 | MSD contingent consideration (European vaccines business)
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 2 | Other contingent consideration arising from business combinations
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 2 | Liabilities related to non-controlling interests
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 2 | Non-current derivatives
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	92	10	7
Level 2 | Current derivatives
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	205	89	90
Level 2 | Quoted equity investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 2 | Unquoted equity investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 2 | Quoted debt securities
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 2 | Unquoted debt securities not meeting the definition of equity instruments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 2 | Contingent consideration relating to divestments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 2 | Financial assets held to meet obligations under deferred compensation plans
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 2 | Non-current derivatives
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	24	37	19
Level 2 | Current derivatives
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	58	188	164
Level 2 | Mutual fund investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 3
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	695	834	631
Total financial liabilities measured at fair value	605	800	1,205
Level 3 | CVRs issued in connection with the acquisition of Genzyme
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 3 | Bayer contingent purchase consideration arising from the acquisition of Genzyme
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	104	156	472
Level 3 | MSD contingent consideration (European vaccines business)
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	312	385	410
Level 3 | Other contingent consideration arising from business combinations
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	189	259	301
Level 3 | Liabilities related to non-controlling interests
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	22
Level 3 | Non-current derivatives
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 3 | Current derivatives
Disclosure of information on income statement [line items]
Total financial liabilities measured at fair value	0	0	0
Level 3 | Quoted equity investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 3 | Unquoted equity investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	149	290	197
Level 3 | Quoted debt securities
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 3 | Unquoted debt securities not meeting the definition of equity instruments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	63	52	61
Level 3 | Contingent consideration relating to divestments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	483	492	373
Level 3 | Financial assets held to meet obligations under deferred compensation plans
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 3 | Non-current derivatives
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 3 | Current derivatives
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	0	0	0
Level 3 | Mutual fund investments
Disclosure of information on income statement [line items]
Total financial assets measured at fair value	€ 0	€ 0	€ 0

Financial assets and liabilit_4

Financial assets and liabilities measured at fair value - Additional Information (Details) - Sanofi Pasteur MSD € in Millions	Dec. 31, 2020EUR (€)
Contingent consideration relating to divestments
Disclosure of information on income statement [line items]
Financial assets measured at fair value	€ 483
Other contingent consideration arising from business combinations
Disclosure of information on income statement [line items]
Financial liabilities measured at fair value	€ 312

Cash and cash equivalents (Deta

Cash and cash equivalents (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Subclassifications of assets, liabilities and equities [abstract]
Cash	€ 1,144	€ 701	€ 661
Cash equivalents	12,771	8,726	6,264
Cash and cash equivalents	13,915	9,427	6,925	€ 10,315
Cash equivalents, money market mutual funds	8,703	5,304	3,189
Cash equivalents, term deposits	3,259	2,211	2,014
Cash equivalents, commercial paper	74	446	357
Cash equivalent, captive insurance and reinsurance companies	€ 425	€ 456	€ 505

Net deferred tax position - Sum

Net deferred tax position - Summary of Net Deferred Tax Position (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	€ 2,442	€ 3,140	€ 1,199
Deferred tax liabilities	(1,770)	(2,294)	(3,414)
Reserves likely to be distributed in the foreseeable future	47,800
Deferred tax assets	4,212	5,434	4,613
Deferred tax liabilities	1,770	2,294	3,414
Consolidation adjustments (intragroup margin in inventory)
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	1,142	1,270	1,195
Provision for pensions and other employee benefits
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	1,213	1,327	1,166
Remeasurement of other acquired intangible assets
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	(3,083)	(2,656)	(3,740)
Remeasurement of other acquired intangible assets | Bioverativ
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax liabilities	(1,021)
Deferred tax liabilities	1,021
Remeasurement of other acquired intangible assets | Principia
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax liabilities	(547)
Deferred tax liabilities	547
Remeasurement of other acquired intangible assets | Genzyme
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax liabilities	(367)
Deferred tax liabilities	367
Remeasurement of other acquired intangible assets | Synthorx
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax liabilities	(315)
Deferred tax liabilities	315
Recognition of acquired property, plant and equipment at fair value
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	(27)	(33)	(31)
Equity interests in subsidiaries and investments in other entities
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	(522)	(421)	(437)
Tax losses available for carry-forward
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	1,327	1,323	1,341
Stock options and other share-based payments
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	88	142	110
Accrued expenses and provisions deductible at time of payments
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	1,399	1,405	1,394
Other
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Net deferred tax asset/(liability)	905	783	201
Deferred tax relating to restructuring provisions
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax assets	€ 307	€ 259	€ 218

Net deferred tax position - Add

Net deferred tax position - Additional information (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Temporary differences associated with investments in subsidiaries, branches and associates and interests in joint arrangements for which deferred tax liabilities have not been recognised	€ 11,500	€ 10,900	€ 10,200
Total deferred tax assets for tax loss carryforwards	1,658	1,640	1,651
Unused tax losses for which no deferred tax asset recognised	331	317	310
Deferred tax assets not recognized as future recovery not probable	€ 346	€ 340	€ 298

Net deferred tax position - S_2

Net deferred tax position - Summary of Tax Losses Available for Carry-forward (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of tax losses available for carryforward [line items]
Tax losses available for carry-forward	€ 6,515	€ 6,401	€ 6,100
Tax loss carry-forwards on asset disposals	6	€ 1	€ 1
2021
Disclosure of tax losses available for carryforward [line items]
Tax losses available for carry-forward	53
2022
Disclosure of tax losses available for carryforward [line items]
Tax losses available for carry-forward	37
2023
Disclosure of tax losses available for carryforward [line items]
Tax losses available for carry-forward	36
2024
Disclosure of tax losses available for carryforward [line items]
Tax losses available for carry-forward	10
2025
Disclosure of tax losses available for carryforward [line items]
Tax losses available for carry-forward	38
2026 and later
Disclosure of tax losses available for carryforward [line items]
Tax losses available for carry-forward	€ 6,341

Consolidated shareholders_ eq_3

Consolidated shareholders’ equity - Additional Information (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of classes of share capital [line items]
Share capital	€ 2,517,943,476
Number of shares (in shares)	1,258,971,738
Par value per share (in euros per share)	€ 2
Hedges of net investments in foreign operations	€ (136,000,000)	€ (260,000,000)	€ (145,000,000)
Number of stock option not taken for computing diluted earning per share (in shares)	600,000	800,000	2,500,000
April 28, 2020
Disclosure of classes of share capital [line items]
Period of share repurchase program	18 months
April 30, 2019
Disclosure of classes of share capital [line items]
Period of share repurchase program		18 months
May 2, 2018
Disclosure of classes of share capital [line items]
Period of share repurchase program			18 months
May 10, 2017
Disclosure of classes of share capital [line items]
Period of share repurchase program				18 months
Stock subscription option plan
Disclosure of classes of share capital [line items]
Increase in shareholders equity due to exercise of stock purchase option	€ 195,000,000

Consolidated shareholders_ eq_4

Consolidated shareholders’ equity - Summary of Treasury Shares Held (Details) - shares shares in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Capital, Reserves And Other Equity Interest [Abstract]
Number of shares (in shares)	8,280	20	1,940	170
% of share capital for the period	0.658%	0.002%	0.156%	0.014%

Consolidated shareholders_ eq_5

Consolidated shareholders’ equity - Summary of Movements Share Capital (Details) - shares	Jul. 28, 2020	Dec. 18, 2018	Jul. 27, 2018	Apr. 26, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Ending balance (in shares)					1,258,971,738
Share capital | Sanofi Oy
Disclosure of classes of share capital [line items]
Beginning balance (in shares)					1,253,846,111	1,247,395,472	1,254,019,904
Capital increase by exercise of stock subscription options (in shares)					868,655	2,745,853	1,168,808
Capital increase by issuance of restricted shares (in shares)					1,666,256	3,704,786	2,152,183
Reduction in share capital by cancellation of treasury shares (in shares)		(5,106,804)		(7,239,803)
Capital increase reserved for employees (in shares)	2,590,716		2,401,184
Ending balance (in shares)					1,258,971,738	1,253,846,111	1,247,395,472

Consolidated shareholders_ eq_6

Consolidated shareholders’ equity - Principal Characteristics of Restricted Share Plans (Details) € / shares in Units, € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)shares€ / shares	Dec. 31, 2019EUR (€)shares€ / shares	Dec. 31, 2018EUR (€)shares€ / shares
Restricted share plan 2020 | Performance share plan one
Disclosure of classes of share capital [line items]
Service period	3 years
Total number of shares awarded (in shares)	3,340,501
Fair value of plan at the date of grant | €	€ 270
Restricted share plan 2020 | Performance share plan one | Without Market Condition
Disclosure of classes of share capital [line items]
Total number of shares awarded (in shares)	2,536,893
Fair value per share awarded (in euros per share) | € / shares	€ 82.36
Restricted share plan 2020 | Performance share plan one | With Market Condition
Disclosure of classes of share capital [line items]
Total number of shares awarded (in shares)	803,608
Fair value per share awarded (in euros per share) | € / shares	€ 76.11
Restricted share plan 2020 | Performance share plan two
Disclosure of classes of share capital [line items]
Service period	3 years
Total number of shares awarded (in shares)	73,027
Fair value of plan at the date of grant | €	€ 5
Restricted share plan 2020 | Performance share plan two | Without Market Condition
Disclosure of classes of share capital [line items]
Total number of shares awarded (in shares)	0
Fair value per share awarded (in euros per share) | € / shares	€ 0
Restricted share plan 2020 | Performance share plan two | With Market Condition
Disclosure of classes of share capital [line items]
Total number of shares awarded (in shares)	73,027
Fair value per share awarded (in euros per share) | € / shares	€ 63.18
Restricted share plan 2019
Disclosure of classes of share capital [line items]
Service period		3 years
Total number of shares awarded (in shares)		3,797,582
Fair value per share awarded (in euros per share) | € / shares		€ 67.90
Fair value of plan at the date of grant | €		€ 258
Restricted share plan 2018 | Performance share plan one
Disclosure of classes of share capital [line items]
Service period			3 years
Total number of shares awarded (in shares)			141,669
Fair value per share awarded (in euros per share) | € / shares			€ 64.35
Fair value of plan at the date of grant | €			€ 9
Restricted share plan 2018 | Performance share plan two
Disclosure of classes of share capital [line items]
Service period			3 years
Total number of shares awarded (in shares)			4,390,216
Fair value per share awarded (in euros per share) | € / shares			€ 56.59
Fair value of plan at the date of grant | €			€ 248

Consolidated shareholders_ eq_7

Consolidated shareholders’ equity - Summary of Number of Restricted Shares Not Yet Fully Vested (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted shares
Disclosure of classes of share capital [line items]
Total expense for restricted share plans	€ 222	€ 247	€ 248
Number of shares not yet fully vested (in shares)	10,546,612	10,908,503	13,576,464
Restricted share plan 2020
Disclosure of classes of share capital [line items]
Number of shares not yet fully vested (in shares)	3,284,558	0	0
Restricted share plan 2019
Disclosure of classes of share capital [line items]
Number of shares not yet fully vested (in shares)	3,375,717	3,662,806	0
Restricted share plan 2018
Disclosure of classes of share capital [line items]
Number of shares not yet fully vested (in shares)	3,886,337	4,117,795	4,406,593
Restricted share plan 2017
Disclosure of classes of share capital [line items]
Number of shares not yet fully vested (in shares)	0	3,127,902	3,314,391
Restricted Share Plan 2016
Disclosure of classes of share capital [line items]
Number of shares not yet fully vested (in shares)	0	0	3,690,226
Restricted share plan 2015
Disclosure of classes of share capital [line items]
Number of shares not yet fully vested (in shares)	0	0	2,165,254

Consolidated shareholders_ eq_8

Consolidated shareholders’ equity - Summary of Characteristics of Employee Share Ownership Plans Awarded (Details) - € / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018	Feb. 05, 2020	Mar. 06, 2018
Disclosure of classes of share capital [line items]
Subscription price (as a percent)	80.00%	80.00%
Number of trading days preceding plan approval	20 days	20 days
Employees share ownership plan
Disclosure of classes of share capital [line items]
Subscription price (in euros per share)			€ 70.67	€ 52.66
Number of shares subscribed (in shares)			2,467,101	2,298,783
Number of shares issued immediately as employer's contribution (in shares)			123,615,000,000	102,401

Consolidated shareholders_ eq_9

Consolidated shareholders’ equity - Summary of Expenses (Details) - Employees share ownership plan - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Expense recognized	€ 52	€ 32
Expense recognized of which employers' contribution	€ 11	€ 7

Consolidated shareholders_ e_10

Consolidated shareholders’ equity - Summary of Repurchases Program (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share repurchase 2020 program
Disclosure of classes of share capital [line items]
Number of shares (in shares)	5,685,426
Value	€ 461
Share repurchase 2019 program
Disclosure of classes of share capital [line items]
Number of shares (in shares)	3,982,939
Value	€ 361
Share repurchase 2018 program
Disclosure of classes of share capital [line items]
Number of shares (in shares)		147,793	6,884,792
Value		€ 12	€ 501
Share repurchase 2017 program
Disclosure of classes of share capital [line items]
Number of shares (in shares)			8,489,873
Value			€ 602

Consolidated shareholders_ e_11

Consolidated shareholders’ equity - Summary of Currency Translation Differences (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	[1]
Disclosure of classes of share capital [line items]
Attributable to equity holders of Sanofi	€ 63,001	€ 58,934	€ 58,876
Attributable to non-controlling interests	146	174	159
Total equity	63,147	59,108	59,035	€ 58,239
Reserve of exchange differences on translation
Disclosure of classes of share capital [line items]
Attributable to equity holders of Sanofi	(3,386)	632	(167)
Attributable to non-controlling interests	(55)	(36)	(36)
Total equity	€ (3,441)	€ 596	€ (203)
[1]	Includes the effects of first-time application of IFRS 15 on revenue recognition.

Consolidated shareholders_ e_12

Consolidated shareholders’ equity - Summary of Movements within Other Comprehensive Income (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of analysis of other comprehensive income by item [line items]
Items not subsequently reclassifiable to profit or loss	€ 12,000,000	€ (163,000,000)	€ (305,000,000)
Items subsequently reclassifiable to profit or loss	(4,022,000,000)	813,000,000	1,264,000,000
Items subsequently reclassifiable to profit or loss
Disclosure of analysis of other comprehensive income by item [line items]
Items subsequently reclassifiable to profit or loss	1,000,000	27,000,000	(7,000,000)
Items subsequently reclassifiable to profit or loss | Debt instruments
Disclosure of analysis of other comprehensive income by item [line items]
Items subsequently reclassifiable to profit or loss	5,000,000	0	0
Accumulated other comprehensive income | Items not subsequently reclassifiable to profit or loss
Disclosure of analysis of other comprehensive income by item [line items]
Actuarial gains/(losses) excluding investments accounted for using the equity method	(267,000,000)	(377,000,000)	201,000,000
Actuarial gains/(losses) of investments accounted for using the equity method, net of taxes	(1,000,000)	(5,000,000)	0
Tax effects	45,000,000	161,000,000	(69,000,000)
Accumulated other comprehensive income | Items not subsequently reclassifiable to profit or loss | Equity instruments included in financial assets
Disclosure of analysis of other comprehensive income by item [line items]
Change in fair value (excluding investments accounted for using the equity method)	358,000,000	30,000,000	(529,000,000)
Change in fair value (investments accounted for using the equity method, net of taxes)	(14,000,000)	80,000,000	(8,000,000)
Equity risk hedging instruments designated as fair value hedges	(24,000,000)	(4,000,000)	0
Tax effects	(85,000,000)	(48,000,000)	100,000,000
Items not subsequently reclassifiable to profit or loss	12,000,000	(163,000,000)	(305,000,000)
Accumulated other comprehensive income | Items subsequently reclassifiable to profit or loss
Disclosure of analysis of other comprehensive income by item [line items]
Change in fair value (excluding investments accounted for using the equity method)	4,000,000	(13,000,000)	3,000,000
Change in fair value (investments accounted for using the equity method, net of taxes)	0	0	0
Tax effects	(2,000,000)	4,000,000	(1,000,000)
Currency translation differences on foreign subsidiaries (excluding investments accounted for using the equity method)	(3,872,000,000)	850,000,000	1,273,000,000
Currency translation differences (investments accounted for using the equity method)	32,000,000	64,000,000	106,000,000
Hedges of net investments in foreign operations	180,000,000	(163,000,000)	(185,000,000)
Tax effects	58,000,000	(48,000,000)	(72,000,000)
Items subsequently reclassifiable to profit or loss	(4,022,000,000)	813,000,000	1,264,000,000
Accumulated other comprehensive income | Items subsequently reclassifiable to profit or loss | Regeneron
Disclosure of analysis of other comprehensive income by item [line items]
Currency translation differences (investments accounted for using the equity method)	(318,000,000)	0	0
Tax effects	2,000,000
Accumulated other comprehensive income | Items subsequently reclassifiable to profit or loss | Debt instruments
Disclosure of analysis of other comprehensive income by item [line items]
Change in fair value (excluding investments accounted for using the equity method)	15,000,000	28,000,000	(4,000,000)
Change in fair value (investments accounted for using the equity method, net of taxes)	0	0	0
Tax effects	€ (3,000,000)	€ (5,000,000)	€ 0

Consolidated shareholders_ e_13

Consolidated shareholders’ equity - Summary of Stock Option Plans Awarded and Measurement of Stock Option Plans (Details) € / shares in Units, € in Millions	Apr. 30, 2019EUR (€)shares€ / shares	May 02, 2018EUR (€)shares€ / shares
Share Capital, Reserves And Other Equity Interest [Abstract]
Total number of options granted (in shares) | shares	220,000	220,000
Exercise price (in euros per share)	€ 76.71	€ 65.84
Award vesting/service period	4 years	4 years
Fair value of the plan | €	€ 2	€ 1
Fair value per option granted (in euros per share)	€ 7.80	€ 6.32
Dividend yield	4.31%	4.87%
Volatility of Sanofi shares, computed on a historical basis	22.48%	23.10%
Risk-free interest rate	0.15%	0.36%
Plan maturity	8 years	7 years

Consolidated shareholders_ e_14

Consolidated shareholders’ equity - Disclosure of Stock Subscription Option Plan Outstanding and Option Exercised (Details)	Apr. 30, 2019shares	May 02, 2018shares	May 10, 2017shares	Jun. 24, 2015shares	Mar. 05, 2014shares	Mar. 05, 2013shares	Mar. 05, 2012shares	Mar. 09, 2011shares	Mar. 01, 2010shares	Dec. 31, 2020shares€ / shares	May 04, 2016shares
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)	220,000	220,000
Stock subscription option plan one
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)									8,121,355
Exercise price (in euros per share) | € / shares										€ 54.12
Number of options outstanding (in shares)										0
Stock subscription option plan two
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)								874,500
Exercise price (in euros per share) | € / shares										€ 50.48
Number of options outstanding (in shares)										32,448
Stock subscription option plan three
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)							814,050
Exercise price (in euros per share) | € / shares										€ 56.44
Number of options outstanding (in shares)										173,867
Stock subscription option plan four
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)						788,725
Exercise price (in euros per share) | € / shares										€ 72.19
Number of options outstanding (in shares)										380,256
Stock subscription option plan five
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)					1,009,250
Exercise price (in euros per share) | € / shares										€ 73.48
Number of options outstanding (in shares)										634,265
Stock subscription option plan six
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)				435,000
Exercise price (in euros per share) | € / shares										€ 89.38
Number of options outstanding (in shares)										339,964
Stock subscription option plan seven
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)											402,750
Exercise price (in euros per share) | € / shares										€ 75.90
Number of options outstanding (in shares)										284,250
Stock subscription option plan eight
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)			378,040
Exercise price (in euros per share) | € / shares										€ 88.97
Number of options outstanding (in shares)										294,220
Stock subscription option plan nine
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)		220,000
Exercise price (in euros per share) | € / shares										€ 65.84
Number of options outstanding (in shares)										220,000
Stock subscription option plan ten
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options granted (in shares)	220,000
Exercise price (in euros per share) | € / shares										€ 76.71
Number of options outstanding (in shares)										220,000
Stock subscription option plan
Disclosure of stock subscription option plan outstanding and option exercised [line items]
Number of options outstanding (in shares)										2,579,270

Consolidated shareholders_ e_15

Consolidated shareholders’ equity - Summary of Stock Options Outstanding at Each Balance Sheet Date (Details) - Total stock option plans € / shares in Units, € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)shares€ / shares	Dec. 31, 2019EUR (€)shares€ / shares	Dec. 31, 2018EUR (€)shares€ / shares	Dec. 31, 2017EUR (€)shares€ / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of options, Beginning Balance (in shares) | shares	3,822,020	6,849,573	7,889,020
Number of options, Options exercisable (in shares) | shares	1,845,050	2,650,375	5,468,214	5,812,165
Number of options, Options granted (in shares) | shares		220,000	220,000
Number of options, Options exercised (in shares) | shares	(868,655)	(2,816,123)	(1,192,838)
Number of options, Options cancelled (in shares) | shares	(91,305)	(48,005)	(66,609)
Number of options, Options forfeited (in shares) | shares	(282,790)	(383,425)
Number of options, Ending Balance (in shares) | shares	2,579,270	3,822,020	6,849,573	7,889,020
Average exercise price per share, Beginning Balance (in EUR per share) | € / shares	€ 70.58	€ 61.81	€ 60.08
Average exercise price per share, Options exercisable (in EUR per share) | € / shares	74.51	67.14	56.80	€ 52.93
Average exercise price per share, Options granted (in EUR per share) | € / shares		76.71	65.84
Average exercise price per share, Options exercised (in EUR per share) | € / shares	59.20	53.18	50.02
Average exercise price per share, Options cancelled (in EUR per share) | € / shares	87.73	72.84	82.03
Average exercise price per share, Options forfeited (in EUR per share) | € / shares	54.12	44.90
Average exercise price per share, Ending Balance (in EUR per share) | € / shares	€ 75.61	€ 70.58	€ 61.81	€ 60.08
Total, Beginning Balance | €	€ 270	€ 423	€ 474
Total, Options exercisable | €	137	178	311	€ 308
Total, Options granted | €		17	14
Total, Options exercised | €	(52)	(150)	(60)
Total, Options cancelled | €	(8)	(3)	(5)
Total, Options forfeited | €	(15)	(17)
Total, Ending Balance | €	€ 195	€ 270	€ 423	€ 474

Consolidated shareholders_ e_16

Consolidated shareholders’ equity - Summary of Options Outstanding and Exercisable (Details) - Stock Option Plan	12 Months Ended
	Dec. 31, 2020shares€ / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding, Number of options (in shares) | shares	2,579,270
Exercisable, Number of options (in shares) | shares	1,845,050
Exercise Price Range One
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding, Number of options (in shares) | shares	206,315
Weighted average residual life (years)	1 year 7 days
Weighted average exercise price of share options outstanding in share-based payment arrangement	€ 55.50
Exercisable, Number of options (in shares) | shares	206,315
Weighted average exercise price per share, Options exercisable (in EUR per share)	€ 55.50
Exercise Price Range Two
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding, Number of options (in shares) | shares	220,000
Weighted average residual life (years)	7 years 4 months 2 days
Weighted average exercise price of share options outstanding in share-based payment arrangement	€ 65.84
Exercisable, Number of options (in shares) | shares	0
Weighted average exercise price per share, Options exercisable (in EUR per share)	€ 0
Exercise Price Range Three
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding, Number of options (in shares) | shares	1,518,771
Weighted average residual life (years)	4 years 29 days
Weighted average exercise price of share options outstanding in share-based payment arrangement	€ 74.08
Exercisable, Number of options (in shares) | shares	1,298,771
Weighted average exercise price per share, Options exercisable (in EUR per share)	€ 73.63
Exercise Price Range Four
Disclosure of terms and conditions of share-based payment arrangement [line items]
Outstanding, Number of options (in shares) | shares	634,184
Weighted average residual life (years)	5 years 4 months 6 days
Weighted average exercise price of share options outstanding in share-based payment arrangement	€ 89.19
Exercisable, Number of options (in shares) | shares	339,964
Weighted average exercise price per share, Options exercisable (in EUR per share)	€ 89.38
Bottom of range | Exercise Price Range One
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	50
Bottom of range | Exercise Price Range Two
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	60
Bottom of range | Exercise Price Range Three
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	70
Bottom of range | Exercise Price Range Four
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	80
Top of range | Exercise Price Range One
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	60
Top of range | Exercise Price Range Two
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	70
Top of range | Exercise Price Range Three
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	80
Top of range | Exercise Price Range Four
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding options (in euros per share)	€ 90

Consolidated shareholders_ e_17

Consolidated shareholders’ equity - Summary of Number of Shares Used to Compute Diluted Earnings Per Share (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Capital, Reserves And Other Equity Interest [Abstract]
Average number of shares outstanding (in shares)	1,253.6	1,249.9	1,247.1
Adjustment for stock options with dilutive effect (in shares)	0.4	0.8	1.3
Adjustment for restricted shares (in shares)	6.1	6.4	6.8
Average number of shares used to compute diluted earnings per share (in shares)	1,260.1	1,257.1	1,255.2

Debt, cash and cash equivalen_3

Debt, cash and cash equivalents and lease liabilities - Summary of Changes in Financial Position (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financial Instruments [Abstract]
Long-term debt	€ 19,745	€ 20,131	€ 22,007
Short-term debt and current portion of long-term debt	2,767	4,554	2,633
Interest rate and currency derivatives used to manage debt	119	(117)	(54)
Total debt	22,631	24,568	24,586
Cash and cash equivalents	(13,915)	(9,427)	(6,925)	€ (10,315)
Interest rate and currency derivatives used to manage cash and cash equivalents	74	(34)	(33)
Net debt	8,790	15,107	€ 17,628
Current and non-current lease liabilities	€ 1,163	€ 1,248

Debt, cash and cash equivalen_4

Debt, cash and cash equivalents and lease liabilities - Summary of Reconciliation of Carrying Amount to Value on Redemption (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Long-term debt	€ 19,745	€ 20,131	€ 22,007
Short-term debt and current portion of long-term debt	2,767	4,554	2,633
Interest rate and currency derivatives used to manage debt	119	(117)	(54)
Total debt	22,631	24,568	24,586
Cash and cash equivalents	(13,915)	(9,427)	(6,925)	€ (10,315)
Interest rate and currency derivatives used to manage cash and cash equivalents	74	(34)	(33)
Net debt	8,790	15,107	17,628
Amortized cost
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Long-term debt	70
Short-term debt and current portion of long-term debt	(2)
Interest rate and currency derivatives used to manage debt
Total debt	68
Cash and cash equivalents
Interest rate and currency derivatives used to manage cash and cash equivalents
Net debt	68
Adjustment to debt measured at fair value
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Long-term debt	(21)
Short-term debt and current portion of long-term debt	2
Interest rate and currency derivatives used to manage debt	23
Total debt	4
Cash and cash equivalents
Interest rate and currency derivatives used to manage cash and cash equivalents
Net debt	4
Value on redemption
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Long-term debt		20,180	22,071
Short-term debt and current portion of long-term debt	2,767	4,553	2,613
Interest rate and currency derivatives used to manage debt	142	(86)	(12)
Total debt	22,703	24,647	24,672
Cash and cash equivalents	(13,915)	(9,427)	(6,925)
Interest rate and currency derivatives used to manage cash and cash equivalents	74	(34)	(33)
Net debt	€ 8,862	€ 15,186	€ 17,714

Debt, cash and cash equivalen_5

Debt, cash and cash equivalents and lease liabilities - Disclosure of Movement In Total Debt (Details) € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)
Disclosure of debt [line items]
December 31, 2019	€ 24,568
Repayments	(3,952)
New borrowings	2,019
Other cash flows	282
Currency translation differences	(385)
Reclassification from non-current to current	0
Other items	99
December 31, 2020	22,631
Long-term debt
Disclosure of debt [line items]
December 31, 2019	20,131
Repayments	0
New borrowings	2,019
Other cash flows	0
Currency translation differences	(152)
Reclassification from non-current to current	(2,285)
Other items	32
December 31, 2020	19,745
Short-term debt and current portion of long-term debt
Disclosure of debt [line items]
December 31, 2019	4,554
Repayments	(3,952)
New borrowings	0
Other cash flows	86
Currency translation differences	(219)
Reclassification from non-current to current	2,285
Other items	13
December 31, 2020	2,767
Interest rate and currency derivatives used to manage debt
Disclosure of debt [line items]
December 31, 2019	(117)
Repayments	0
New borrowings	0
Other cash flows	196
Currency translation differences	(14)
Reclassification from non-current to current	0
Other items	54
December 31, 2020	€ 119

Debt, cash and cash equivalen_6

Debt, cash and cash equivalents and lease liabilities - Additional Information (Details) $ in Billions	Dec. 31, 2020EUR (€)extensioncurrencycredit_facilityshares	Dec. 08, 2020EUR (€)extensioncredit_facilityperformance_indicator	Apr. 30, 2020EUR (€)tranche	Mar. 31, 2020EUR (€)tranche	Dec. 31, 2020EUR (€)extensioncounterpartycurrencycredit_facilitybondshares	Dec. 31, 2020USD ($)extensioncurrencycredit_facilityshares	Mar. 31, 2018EUR (€)	Sep. 30, 2016EUR (€)	Sep. 30, 2013EUR (€)	Jun. 30, 2010EUR (€)
Disclosure of detailed information about borrowings [line items]
Notional amount	€ 19,794,000,000		€ 500,000,000		€ 19,794,000,000
Number of bond issues redeemed | bond					5
Number of currencies debt is issued in | currency	2				2	2
March 2020 1.5 Billion Bond
Disclosure of detailed information about borrowings [line items]
Notional amount				€ 1,500,000,000
Number of tranches | tranche				2
750 million bonds maturing April 2025
Disclosure of detailed information about borrowings [line items]
Notional amount				€ 750,000,000
Bonds, interest rate				1.00%
750 million bonds maturing April 2030
Disclosure of detailed information about borrowings [line items]
Notional amount				€ 750,000,000
Bonds, interest rate				1.50%
April 2020 500 Million Tap Issue
Disclosure of detailed information about borrowings [line items]
Number of tranches | tranche			2
250 million bonds maturing April 2025
Disclosure of detailed information about borrowings [line items]
Notional amount			€ 250,000,000
Bonds, interest rate			1.00%
250 million bonds maturing April 2025
Disclosure of detailed information about borrowings [line items]
Notional amount			€ 250,000,000
Bonds, interest rate			1.50%
1 billion bonds maturing January 2020
Disclosure of detailed information about borrowings [line items]
Notional amount								€ 1,000,000,000
500 million bonds maturing March 2020
Disclosure of detailed information about borrowings [line items]
Notional amount							€ 500,000,000
1 billion bonds maturing March 2020
Disclosure of detailed information about borrowings [line items]
Notional amount							€ 1,000,000,000
1 billion bonds maturing September 2020, redeemed early June 2020
Disclosure of detailed information about borrowings [line items]
Notional amount									€ 1,000,000,000
500 million bonds maturing June 2020
Disclosure of detailed information about borrowings [line items]
Notional amount										€ 500,000,000
Sanofi sustainability-linked credit facilities
Disclosure of detailed information about borrowings [line items]
Notional amount	€ 4,000,000,000				€ 4,000,000,000
Credit facilities, number of extension options | extension	2				2	2
Credit facilities, extension option (in years)	1 year
Credit facilities, number of performance indicators | performance_indicator		2
Number of credit facilities | credit_facility	2	2			2	2
Syndicated credit facility, expires in 2021
Disclosure of detailed information about borrowings [line items]
Credit facilities, number of extension options | extension		2
Credit facilities, extension option (in years)		1 year
Syndicated credit facility, expires in 2025
Disclosure of detailed information about borrowings [line items]
Notional amount		€ 4,000,000,000
Credit facilities, number of extension options | extension		2
Credit facilities, extension option (in years)		1 year
Syndicated credit facility cancelled		€ 4,000,000,000
Sanofi Euro Medium Term Notes (EMTN) bonds | Weighted average interest rate before derivative instruments
Disclosure of detailed information about borrowings [line items]
Bonds, interest rate	1.60%				1.60%	1.60%
Cash and cash equivalents interest rate	0.00%				0.00%	0.00%
Sanofi Euro Medium Term Notes (EMTN) bonds | Weighted average interest rate after derivative instruments
Disclosure of detailed information about borrowings [line items]
Bonds, interest rate	1.70%				1.70%	1.70%
Cash and cash equivalents interest rate	0.40%				0.40%	0.40%
Sanofi Euro Medium Term Notes (EMTN) bonds | 1983 to 1987 Participating Shares Issued
Disclosure of detailed information about borrowings [line items]
Number of participating shares outstanding (in shares) | shares	76,986				76,986	76,986
Participating shares carrying amount	€ 12,000,000				€ 12,000,000
Sanofi Euro Medium Term Notes (EMTN) bonds | Commercial paper program in France
Disclosure of detailed information about borrowings [line items]
Commercial paper programs	6,000,000,000				6,000,000,000
Average drawdown	1,500,000,000				1,500,000,000
Maximum drawdown	4,000,000,000				4,000,000,000
Sanofi Euro Medium Term Notes (EMTN) bonds | Commercial paper program in USA
Disclosure of detailed information about borrowings [line items]
Commercial paper programs | $						$ 10
Sanofi Euro Medium Term Notes (EMTN) bonds | Main undrawn confirmed general purpose credit facilities
Disclosure of detailed information about borrowings [line items]
Notional amount	€ 8,000,000,000				€ 8,000,000,000
Number of counterparty representing more than 6% of undrawn credit facility | counterparty					0
Sanofi Euro Medium Term Notes (EMTN) bonds | Syndicated credit facility, expires in 2021
Disclosure of detailed information about borrowings [line items]
Credit facilities, number of extension options | extension	2				2	2
Credit facilities, extension option (in years)	1 year
Credit facilities, maximum amount	€ 4,000,000,000				€ 4,000,000,000
Sanofi Euro Medium Term Notes (EMTN) bonds | Syndicated credit facility, expires in 2025
Disclosure of detailed information about borrowings [line items]
Credit facilities, number of extension options | extension	2				2	2
Credit facilities, extension option (in years)	1 year
Credit facilities, maximum amount	€ 4,000,000,000				€ 4,000,000,000

Debt, cash and cash equivalen_7

Debt, cash and cash equivalents and lease liabilities - Summary of Net Debt by Type Valuation of Redemption (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Interest rate and currency derivatives used to manage debt	€ 119	€ (117)	€ (54)
Total debt	22,631	24,568	24,586
Cash and cash equivalents	(13,915)	(9,427)	(6,925)	€ (10,315)
Interest rate and currency derivatives used to manage cash and cash equivalents	74	(34)	(33)
Net debt	8,790	15,107	17,628
Value on redemption
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Bond issues	21,978	24,207	24,164
Other bank borrowings	296	196	233
Finance lease liabilities	0	0	22
Other borrowings	2	25	16
Bank credit balances	285	305	249
Interest rate and currency derivatives used to manage debt	142	(86)	(12)
Total debt	22,703	24,647	24,672
Cash and cash equivalents	(13,915)	(9,427)	(6,925)
Interest rate and currency derivatives used to manage cash and cash equivalents	74	(34)	(33)
Net debt	8,862	15,186	17,714
Value on redemption | Non-current assets
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Cash and cash equivalents	0	0	0
Interest rate and currency derivatives used to manage cash and cash equivalents	6	(6)	0
Net debt	19,857	20,175	22,071
Value on redemption | Current assets
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Cash and cash equivalents	(13,915)	(9,427)	(6,925)
Interest rate and currency derivatives used to manage cash and cash equivalents	68	(28)	(33)
Net debt	(10,995)	(4,989)	(4,357)
Value on redemption | Non-current liabilities
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Bond issues	19,698	20,128	21,983
Other bank borrowings	96	40	57
Finance lease liabilities	0	0	18
Other borrowings	0	13	13
Bank credit balances	0	0	0
Interest rate and currency derivatives used to manage debt	57	0	0
Total debt	19,851	20,181	22,071
Value on redemption | Current liabilities
Disclosure of reconciliation of carrying amount to value on redemption [line items]
Bond issues	2,280	4,079	2,181
Other bank borrowings	200	156	176
Finance lease liabilities	0	0	4
Other borrowings	2	12	3
Bank credit balances	285	305	249
Interest rate and currency derivatives used to manage debt	85	(86)	(12)
Total debt	€ 2,852	€ 4,466	€ 2,601

Debt, cash and cash equivalen_8

Debt, cash and cash equivalents and lease liabilities - Summary of Bond Issues (Details) $ in Millions

Dec. 31, 2020EUR (€)

Apr. 30, 2020EUR (€)

Mar. 31, 2020EUR (€)

Mar. 31, 2019EUR (€)

Jun. 30, 2018USD ($)

Mar. 31, 2018EUR (€)

Sep. 30, 2016EUR (€)

Apr. 30, 2016EUR (€)

Sep. 30, 2015EUR (€)

Sep. 30, 2014EUR (€)

Nov. 30, 2013EUR (€)

Mar. 31, 2011USD ($)

Disclosure of detailed information about borrowings [line items]

Amount

€ 19,794,000,000

€ 500,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | November 2013 EMTN ISIN FR0011625433

Disclosure of detailed information about borrowings [line items]

Annual interest rate

2.50%

Amount

€ 1,000,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | September 2014 EMTN ISIN FR0012146777

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.125%

Amount

€ 1,000,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | September 2014 EMTN ISIN FR0012146801

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.75%

Amount

€ 1,510,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | September 2015 EMTN ISIN FR0012969020

Disclosure of detailed information about borrowings [line items]

Annual interest rate

0.875%

Amount

€ 500,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | September 2015 EMTN ISIN FR0012969038

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.50%

Amount

€ 750,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | April 2016 EMTN ISIN FR0013143997

Disclosure of detailed information about borrowings [line items]

Annual interest rate

0.625%

Amount

€ 600,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | April 2016 EMTN ISIN FR00113144003

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.125%

Amount

€ 700,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | September 2016 EMTN ISIN FR0013201621

Disclosure of detailed information about borrowings [line items]

Annual interest rate

0.00%

Amount

€ 850,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | September 2016 EMTNISINFR0013201639

Disclosure of detailed information about borrowings [line items]

Annual interest rate

0.50%

Amount

€ 1,150,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2020 EMTNISINFR0013505104

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.00%

Amount

€ 1,000,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2020 EMTNISINFR0013505112

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.50%

Amount

€ 1,000,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2018 EMTN ISIN FR0013324332

Disclosure of detailed information about borrowings [line items]

Annual interest rate

0.50%

Amount

€ 1,750,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2018 EMTN ISIN FR0013324340

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.00%

Amount

€ 1,500,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2018 EMTN ISIN FR0013324357

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.375%

Amount

€ 2,000,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2018 EMTN ISIN FR0013324373

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.875%

Amount

€ 1,250,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2019 EMTN ISIN FR0013409836

Disclosure of detailed information about borrowings [line items]

Annual interest rate

0.00%

Amount

€ 850,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2019 EMTN ISIN FR0013409844

Disclosure of detailed information about borrowings [line items]

Annual interest rate

0.875%

Amount

€ 650,000,000

Sanofi Euro Medium Term Notes (EMTN) bonds | March 2019 EMTN ISIN FR0013409851

Disclosure of detailed information about borrowings [line items]

Annual interest rate

1.25%

Amount

€ 500,000,000

Shelf registration statement program | March 2011 SNFISIN US80105NAG07

Disclosure of detailed information about borrowings [line items]

Annual interest rate

4.00%

Amount | $

$ 2,000

Shelf registration statement program | June 2018 SNFISINUS801060AC87

Disclosure of detailed information about borrowings [line items]

Annual interest rate

3.375%

Amount | $

$ 1,000

Shelf registration statement program | June 2018 SNFISINUS801060AD60

Disclosure of detailed information about borrowings [line items]

Annual interest rate

3.625%

Amount | $

$ 1,000

Debt, cash and cash equivalen_9

Debt, cash and cash equivalents and lease liabilities - Summary of Debt by Maturity at Value on Redemption (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about borrowings [line items]
Interest rate and currency derivatives used to manage debt	€ 119	€ (117)	€ (54)
Total debt	22,631	24,568	24,586
Cash and cash equivalents	(13,915)	(9,427)	(6,925)	€ (10,315)
Interest rate and currency derivatives used to manage cash and cash equivalents	74	(34)	(33)
Net debt	8,790	15,107	17,628
Lease liability total	1,163	1,248
2021
Disclosure of detailed information about borrowings [line items]
Lease liability total	247	272
2026 and later
Disclosure of detailed information about borrowings [line items]
Lease liability total	482	540
Value on redemption
Disclosure of detailed information about borrowings [line items]
Bond issues	21,978	24,207	24,164
Other bank borrowings	296	196	233
Finance lease obligations	0	0	22
Other borrowings	2	25	16
Bank credit balances	285	305	249
Interest rate and currency derivatives used to manage debt	142	(86)	(12)
Total debt	22,703	24,647	24,672
Cash and cash equivalents	(13,915)	(9,427)	(6,925)
Interest rate and currency derivatives used to manage cash and cash equivalents	74	(34)	(33)
Net debt	8,862	15,186	17,714
Value on redemption | 2021
Disclosure of detailed information about borrowings [line items]
Bond issues	2,280	4,079	2,181
Other bank borrowings	200	156	176
Finance lease obligations	0	0	4
Other borrowings	2	12	3
Bank credit balances	285	305	249
Interest rate and currency derivatives used to manage debt	85	(86)	(12)
Total debt	2,852	4,466	2,601
Cash and cash equivalents	(13,915)	(9,427)	(6,925)
Interest rate and currency derivatives used to manage cash and cash equivalents	68	(28)	(33)
Net debt	(10,995)	(4,989)	(4,357)
Value on redemption | 2022
Disclosure of detailed information about borrowings [line items]
Bond issues	2,700	2,284	3,936
Other bank borrowings	73	6	15
Finance lease obligations	0	0	3
Other borrowings	0	0	0
Bank credit balances	0	0	0
Interest rate and currency derivatives used to manage debt	57		0
Total debt	2,830	2,290	3,954
Cash and cash equivalents	0	0	0
Interest rate and currency derivatives used to manage cash and cash equivalents	6	(6)	0
Net debt	2,836	2,284	3,954
Value on redemption | 2023
Disclosure of detailed information about borrowings [line items]
Bond issues	3,569	2,700	2,243
Other bank borrowings	6	6	3
Finance lease obligations	0	0	3
Other borrowings	0	0	0
Bank credit balances	0	0	0
Interest rate and currency derivatives used to manage debt	0		0
Total debt	3,575	2,706	2,249
Cash and cash equivalents	0	0	0
Interest rate and currency derivatives used to manage cash and cash equivalents	0	0	0
Net debt	3,575	2,706	2,249
Value on redemption | 2024
Disclosure of detailed information about borrowings [line items]
Bond issues	600	3,642	1,850
Other bank borrowings	2	23	3
Finance lease obligations	0	0	3
Other borrowings	0	0	0
Bank credit balances	0	0	0
Interest rate and currency derivatives used to manage debt	0	0	0
Total debt	602	3,665	1,856
Cash and cash equivalents	0	0	0
Interest rate and currency derivatives used to manage cash and cash equivalents	0	0	0
Net debt	602	3,665	1,856
Value on redemption | 2025
Disclosure of detailed information about borrowings [line items]
Bond issues	1,750	600	3,622
Other bank borrowings	6	5	28
Finance lease obligations	0	0	4
Other borrowings	0	0	0
Bank credit balances	0	0	0
Interest rate and currency derivatives used to manage debt	0	0	0
Total debt	1,756	605	3,654
Cash and cash equivalents	0	0	0
Interest rate and currency derivatives used to manage cash and cash equivalents	0	0	0
Net debt	1,756	605	3,654
Value on redemption | 2026 and later
Disclosure of detailed information about borrowings [line items]
Bond issues	11,079	10,902	10,332
Other bank borrowings	9	0	8
Finance lease obligations	0	0	5
Other borrowings	0	13	13
Bank credit balances	0	0	0
Interest rate and currency derivatives used to manage debt	0	0	0
Total debt	11,088	10,915	10,358
Cash and cash equivalents	0	0	0
Interest rate and currency derivatives used to manage cash and cash equivalents	0	0	0
Net debt	€ 11,088	€ 10,915	€ 10,358

Debt, cash and cash equivale_10

Debt, cash and cash equivalents and lease liabilities - Summary of Debt by Interest Rate (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of financial instruments by type of interest rate [line items]
Cash and cash equivalents	€ (13,915)	€ (9,427)	€ (6,925)	€ (10,315)
Net debt	8,790	15,107	17,628
Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	€ 22,562
Debt percent	100.00%
Net debt	€ 8,647
Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	€ 21,978
Debt percent	97.00%
Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	€ 584
Cash and cash equivalents	€ (13,915)
Debt percent	3.00%
Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	€ 22,703
Cash and cash equivalents	€ (13,841)	€ (9,461)	€ (6,958)
Debt percent	100.00%	100.00%	100.00%
Net debt	€ 8,862	€ 15,186	€ 17,714
Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	€ 20,713
Debt percent	91.00%	88.00%	76.00%
Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	€ 1,990
Debt percent	9.00%	12.00%	24.00%
2021 | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	€ 2,768
Net debt	(11,147)
2021 | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	2,280
2021 | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	488
Cash and cash equivalents	(13,915)
2021 | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	2,852
Cash and cash equivalents	(13,847)
Net debt	(10,995)
2021 | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	2,358
2021 | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	494
2022 | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	2,773
Net debt	2,773
2022 | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	2,700
2022 | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	73
2022 | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	2,830
Cash and cash equivalents	6
Net debt	2,836
2022 | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	1,357
2022 | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	1,473
2023 | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	3,575
Net debt	3,575
2023 | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	3,569
2023 | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	6
2023 | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	3,575
Net debt	3,575
2023 | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	3,569
2023 | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	6
2024 | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	602
Net debt	602
2024 | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	600
2024 | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	2
2024 | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	602
Net debt	602
2024 | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	600
2024 | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	2
2025 | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	1,756
Net debt	1,756
2025 | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	1,750
2025 | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	6
2025 | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	1,756
Net debt	1,756
2025 | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	1,750
2025 | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	6
2026 and later | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	11,088
Net debt	11,088
2026 and later | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	11,079
2026 and later | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	9
2026 and later | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Debt	11,088
Net debt	11,088
2026 and later | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	11,079
2026 and later | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	9
Euro | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	9,547
Euro | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	18,703
Euro | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	35
Cash and cash equivalents	(9,192)
Euro | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	13,725	€ 17,691	€ 16,511
Euro | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	17,752
Euro | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	415
Cash and cash equivalents	4,442
US dollar | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	(933)
US dollar | Value on redemption before derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	3,275
US dollar | Value on redemption before derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	69
Cash and cash equivalents	(4,278)
US dollar | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	(3,304)	€ (813)	€ 2,197
US dollar | Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	2,960
US dollar | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	69
Cash and cash equivalents	6,333
Japanese yen | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	0
Japanese yen | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	214
Japanese yen | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Debt	215
Singapore dollar | Value on redemption before derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	(1)
Singapore dollar | Value on redemption after derivative instruments
Disclosure of financial instruments by type of interest rate [line items]
Net debt	(2,250)
Singapore dollar | Value on redemption after derivative instruments | Floating-rate debt
Disclosure of financial instruments by type of interest rate [line items]
Cash and cash equivalents	€ 2,250

Debt, cash and cash equivale_11

Debt, cash and cash equivalents and lease liabilities - Summary of Interest Rate of Net Debt at Value on Redemption (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Total debt	€ 22,631	€ 24,568	€ 24,586
Cash and cash equivalents	(13,915)	(9,427)	(6,925)	€ (10,315)
Net debt	8,790	15,107	17,628
Value on redemption after derivative instruments
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Total debt		24,647	24,672
Cash and cash equivalents	(13,841)	(9,461)	(6,958)
Net debt	€ 8,862	€ 15,186	€ 17,714
Debt percent	100.00%	100.00%	100.00%
Value on redemption after derivative instruments | Fixed-rate debt
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Total debt		€ 21,713	€ 18,864
Debt percent	91.00%	88.00%	76.00%
Value on redemption after derivative instruments | Floating-rate debt
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Total debt		€ 2,934	€ 5,808
Debt percent	9.00%	12.00%	24.00%

Debt, cash and cash equivale_12

Debt, cash and cash equivalents and lease liabilities - Summary of Interest Rate Fluctuations of Debt Net of Cash and Cash Equivalents (Details) - Change in Euro and US dollar short-term interest rates € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)
+100 bp
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Impact on pre-tax net income	€ 119
Impact on pre-tax income/(expense) recognized directly in equity	0
+25 bp
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Impact on pre-tax net income	30
Impact on pre-tax income/(expense) recognized directly in equity	0
-25 bp
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Impact on pre-tax net income	(30)
Impact on pre-tax income/(expense) recognized directly in equity	0
-100 bp
Disclosure of Interest Rate of Debt Net of Cash and Cash Equivalent [Line Items]
Impact on pre-tax net income	(119)
Impact on pre-tax income/(expense) recognized directly in equity	€ 0

Debt, cash and cash equivale_13

Debt, cash and cash equivalents and lease liabilities - Summary of Debt by Currency (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Debt By Currency [Line Items]
Net debt	€ 8,790	€ 15,107	€ 17,628
Value on redemption before derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	8,647
Value on redemption after derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	8,862	15,186	17,714
Euro | Value on redemption before derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	9,547
Euro | Value on redemption after derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	13,725	17,691	16,511
US dollar | Value on redemption before derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	(933)
US dollar | Value on redemption after derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	(3,304)	(813)	2,197
Japanese yen | Value on redemption before derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	0
Japanese yen | Value on redemption after derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	214
Singapore dollar | Value on redemption before derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	(1)
Singapore dollar | Value on redemption after derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	(2,250)
Chinese yuan renminbi | Value on redemption before derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	(9)
Chinese yuan renminbi | Value on redemption after derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	(179)
Other currencies | Value on redemption before derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	43
Other currencies | Value on redemption after derivative instruments
Disclosure Of Debt By Currency [Line Items]
Net debt	€ 656	€ (1,692)	€ (994)

Debt, cash and cash equivale_14

Debt, cash and cash equivalents and lease liabilities - Summary of Market Value of Net Debt (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about borrowings [line items]
Total debt	€ 22,631	€ 24,568	€ 24,586
At market value
Disclosure of detailed information about borrowings [line items]
Total debt	10,500	16,370	18,003
Value on redemption
Disclosure of detailed information about borrowings [line items]
Total debt	22,703	24,647	24,672
Total debt at redemption	€ 8,862	€ 15,186	€ 17,714

Debt, cash and cash equivale_15

Debt, cash and cash equivalents and lease liabilities - Amount of Future Undiscounted Contractual Cash Flows Relating to Debt and Derivative Instruments Designated as Hedges of Debt (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of maturity analysis for derivative financial liabilities [line items]
Debt	€ 24,339	€ 26,708	€ 26,881
Principal	22,392	24,596	24,550
Interest	1,947	2,112	2,331
Net cash flows related to derivative instruments	163	(117)	(50)
Total	24,502	26,591	26,831
2021
Disclosure of maturity analysis for derivative financial liabilities [line items]
Debt	2,943	4,775	2,855
Principal	2,622	4,417	2,477
Interest	321	358	378
Net cash flows related to derivative instruments	135	(97)	(45)
Total	3,078	4,678	2,810
2022
Disclosure of maturity analysis for derivative financial liabilities [line items]
Debt	3,019	2,588	4,300
Principal	2,757	2,305	3,955
Interest	262	283	345
Net cash flows related to derivative instruments	28	(11)	(8)
Total	3,047	2,577	4,292
2023
Disclosure of maturity analysis for derivative financial liabilities [line items]
Debt	3,808	2,952	2,519
Principal	3,571	2,710	2,250
Interest	237	242	269
Net cash flows related to derivative instruments	0	(9)	(1)
Total	3,808	2,943	2,518
2024
Disclosure of maturity analysis for derivative financial liabilities [line items]
Debt	791	3,862	2,088
Principal	601	3,646	1,858
Interest	190	216	230
Net cash flows related to derivative instruments	0		4
Total	791	3,862	2,092
2025
Disclosure of maturity analysis for derivative financial liabilities [line items]
Debt	1,937	771	3,856
Principal	1,751	604	3,653
Interest	186	167	203
Net cash flows related to derivative instruments	0		0
Total	1,937	771	3,856
2026 and later
Disclosure of maturity analysis for derivative financial liabilities [line items]
Debt	11,841	11,760	11,263
Principal	11,090	10,914	10,357
Interest	751	846	906
Net cash flows related to derivative instruments	0		0
Total	€ 11,841	€ 11,760	€ 11,263

Debt, cash and cash equivale_16

Debt, cash and cash equivalents and lease liabilities - Lease Liabilities (Details) - EUR (€) € in Millions		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of maturity analysis of finance lease payments receivable [line items]
Current and non-current lease liabilities		€ 1,163	€ 1,248
Discounting effect		148	218
Current lease liabilities	[1]	232	261	€ 0
Non-current lease liabilities	[1]	931	987	€ 0
Current and non-current lease liabilities		1,163	1,248
Effect of discounting		(148)	(218)
Less than 1 year
Disclosure of maturity analysis of finance lease payments receivable [line items]
Current and non-current lease liabilities		247	272
Current and non-current lease liabilities		247	272
From 1 to 3 years
Disclosure of maturity analysis of finance lease payments receivable [line items]
Current and non-current lease liabilities		357	422
Current and non-current lease liabilities		357	422
From 3 to 5 years
Disclosure of maturity analysis of finance lease payments receivable [line items]
Current and non-current lease liabilities		225	232
Current and non-current lease liabilities		225	232
More than 5 years
Disclosure of maturity analysis of finance lease payments receivable [line items]
Current and non-current lease liabilities		482	540
Current and non-current lease liabilities		€ 482	€ 540
[1]	Includes the effects of first-time application of IFRS 16 on leases using the modified retrospective approach, effective January 1, 2019.

Liabilities related to busine_3

Liabilities related to business combinations and to non-controlling interests - Summary of Movements in Liabilities Related to Business Combinations and to Non-Controlling Interests (Details) € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)	Oct. 30, 2019$ / shares	Dec. 31, 2018$ / shares
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Beginning balance	€ 800	€ 1,304	€ 1,369
New transactions(e)			228
Payments made	(122)	(237)	(329)
Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount)	(35)	(46)	(37)
Other movements	(10)	(248)	24
Currency translation differences	(28)	27	49
Ending balance	605	800	1,304
Quoted market price per share of CVRs issued in connection with the acquisition of Genzyme | $ / shares				$ 0.72	$ 0.48
Non-current liabilities related to business combinations and to non-controlling interests	387	508	963
Current liabilities related to business combinations and to non-controlling interests	218	292	341
CVRs issued in connection with the acquisition of Genzyme
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Beginning balance	0	99	75
New transactions(e)			0
Payments made	0	0	0
Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount)	0	49	19
Other movements	0	(153)	0
Currency translation differences	0	5	5
Ending balance	0	0	99
Liabilities Related to Non-controlling Interests
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Beginning balance	0	22	92
New transactions(e)			0
Payments made	0	0	(70)
Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount)	0	0	0
Other movements	0	(22)	0
Currency translation differences	0	0	0
Ending balance	0	0	22
Bayer contingent purchase consideration arising from the acquisition of Genzyme
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Beginning balance	156	472	701
New transactions(e)			0
Payments made	(42)	(113)	(147)
Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount)	9	(214)	(109)
Other movements	(8)	0	0
Currency translation differences	(11)	11	27
Ending balance	104	156	472
MSD contingent consideration (European vaccines business)
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Beginning balance	385	410	420
New transactions(e)			0
Payments made	(78)	(69)	(57)
Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount)	9	38	50
Other movements	0	0	0
Currency translation differences	(4)	6	(3)
Ending balance	312	385	410
Other
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Beginning balance	259	301	81
New transactions(e)			228
Payments made	(2)	(55)	(55)
Fair value remeasurements through profit or loss: (gain)/loss (including unwinding of discount)	(53)	81	3
Other movements	(2)	(73)	24
Currency translation differences	(13)	5	20
Ending balance	€ 189	€ 259	301
True North Therapeutics
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Contingent consideration liabilities			226
Bioverativ employees
Changes In Liabilities Related To Business Combinations And Non-Controlling Interests [Roll Forward]
Contingent consideration liabilities			€ 2

Liabilities related to busine_4

Liabilities related to business combinations and to non-controlling interests - Additional Information (Details) € in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2019USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2018USD ($)	Dec. 31, 2018EUR (€)
Disclosure Of Liabilities Related To Business Combinations And To Noncontrolling Interests [line items]
Commitments relating to contingent consideration in connection with business combinations | €		€ (1,043)		€ 3,503		€ 3,638
MSD contingent consideration (European vaccines business)
Disclosure Of Liabilities Related To Business Combinations And To Noncontrolling Interests [line items]
Increase in fair value of liability	2.00%	2.00%
Contingent consideration liability | €		€ 312		385		410
True North Therapeutics
Disclosure Of Liabilities Related To Business Combinations And To Noncontrolling Interests [line items]
Fair value of the contingent consideration payable to Bioverativ | $	$ 197,000,000		$ 255,000,000		$ 192,000,000
Increase in fair value of liability	1.00%	1.00%
Bayer schering pharma AG
Disclosure Of Liabilities Related To Business Combinations And To Noncontrolling Interests [line items]
Increase in fair value of liability	1.00%	1.00%
Payment to sale of business period	10 years
Milestone payment period	2021
Fair value of the contingent consideration payable to Bayer | €		€ 104		€ 156		€ 472
Bayer schering pharma AG | Top of range
Disclosure Of Liabilities Related To Business Combinations And To Noncontrolling Interests [line items]
Potentiel payments related to percentage of sales of alemtuzumab | $	$ 1,250,000,000
Milestone payment | $	$ 900,000,000

Liabilities related to busine_5

Liabilities related to business combinations and to non-controlling interests - Summary of Maximum Amount of Contingent Consideration Payable and Firm Commitments to Buy Out Non-Controlling Interests (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests [Line Items]
Commitments relating to contingent consideration in connection with business combinations	€ 1,043	€ (3,503)	€ (3,638)
Less than 1 year
Disclosure Of maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests [Line Items]
Commitments relating to contingent consideration in connection with business combinations	228
From 1 to 3 years
Disclosure Of maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests [Line Items]
Commitments relating to contingent consideration in connection with business combinations	351
From 3 to 5 years
Disclosure Of maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests [Line Items]
Commitments relating to contingent consideration in connection with business combinations	192
More than 5 years
Disclosure Of maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests [Line Items]
Commitments relating to contingent consideration in connection with business combinations	272
Bayer schering pharma AG
Disclosure Of maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests [Line Items]
Commitments relating to contingent consideration in connection with business combinations Bayer	400
MSD contingent consideration (European vaccines business)
Disclosure Of maximum amount of contingent consideration payable and firm commitments to buy out non-controlling interests [Line Items]
Commitments relating to contingent consideration in connection with business combinations MSD	€ 400

Provisions, income tax liabil_3

Provisions, income tax liabilities and other liabilities - Summary of Non Current Provisions and Other Non-current Liabilities (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Subclassifications of assets, liabilities and equities [abstract]
Provisions	€ 7,219	€ 7,353	€ 6,883	€ 7,198
Other non-current liabilities	317	288	323
Total	7,536	7,641	7,206
Non-current liabilities	€ 92	€ 10	€ 7

Provisions, income tax liabil_4

Provisions, income tax liabilities and other liabilities - Summary of Movements in Non-current Provisions (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of changes in other provisions [abstract]
Beginning balance	€ 7,353	€ 6,883	€ 7,198
Changes in scope of consolidation	5	(1)	29
Increases in provisions	1,479	1,349	1,037
Provisions utilized	(793)	(522)	(793)
Reversals of unutilized provisions	(525)	(738)	(246)
Transfers	(421)	(154)	(289)
Net interest related to employee benefits, and unwinding of discount	68	109	98
Unrealized gains and losses	0	0	0
Currency translation differences	(214)	50	50
Actuarial gains and losses on defined-benefit plans	267	377	(201)
Ending balance	7,219	7,353	6,883
Provisions for pensions and other post-employment benefits
Reconciliation of changes in other provisions [abstract]
Beginning balance	3,827	3,522	3,959
Changes in scope of consolidation	(3)	(1)	(6)
Increases in provisions	253	213	251
Provisions utilized	(566)	(285)	(529)
Reversals of unutilized provisions	(233)	(209)	(36)
Transfers	12	92	(22)
Net interest related to employee benefits, and unwinding of discount	57	83	70
Unrealized gains and losses	0	0	0
Currency translation differences	(117)	35	36
Actuarial gains and losses on defined-benefit plans	267	377	(201)
Ending balance	3,497	3,827	3,522
Provisions for other long-term benefits
Reconciliation of changes in other provisions [abstract]
Beginning balance	855	761	750
Changes in scope of consolidation	0	0	(2)
Increases in provisions	169	189	93
Provisions utilized	(109)	(102)	(101)
Reversals of unutilized provisions	(5)	(3)	(5)
Transfers	0	(3)	10
Net interest related to employee benefits, and unwinding of discount	2	5	4
Unrealized gains and losses	0	0	0
Currency translation differences	(33)	8	12
Actuarial gains and losses on defined-benefit plans	0	0	0
Ending balance	879	855	761
Restructuring provisions
Reconciliation of changes in other provisions [abstract]
Beginning balance	600	632	514
Changes in scope of consolidation	0	0	0
Increases in provisions	688	393	387
Provisions utilized	(5)	(3)	(3)
Reversals of unutilized provisions	(42)	(15)	(15)
Transfers	(369)	(411)	(251)
Net interest related to employee benefits, and unwinding of discount	1	3	0
Unrealized gains and losses	0	0	0
Currency translation differences	(5)	1	0
Actuarial gains and losses on defined-benefit plans	0	0	0
Ending balance	868	600	632
Other provisions
Reconciliation of changes in other provisions [abstract]
Beginning balance	2,071	1,968	1,975
Changes in scope of consolidation	8	0	37
Increases in provisions	369	554	306
Provisions utilized	(113)	(132)	(160)
Reversals of unutilized provisions	(245)	(511)	(190)
Transfers	(64)	168	(26)
Net interest related to employee benefits, and unwinding of discount	8	18	24
Unrealized gains and losses	0	0	0
Currency translation differences	(59)	6	2
Actuarial gains and losses on defined-benefit plans	0	0	0
Ending balance	€ 1,975	€ 2,071	€ 1,968

Provisions, income tax liabil_5

Provisions, income tax liabilities and other liabilities - Additional Information (Details) € in Millions	Dec. 31, 2020EUR (€)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)	Dec. 31, 2020EUR (€)Countryplanage	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)	Dec. 31, 2017EUR (€)
Provisions and other non-current liabilities [Line Items]
Number of major countries included in pension obligations | Country				4
Pension obligation, percentage to defined benefit liability	89.00%			89.00%
Pension obligations, percentage to plan assets	87.00%			87.00%
Employee termination benefits	€ 1,260	€ 1,125	€ 895	€ 1,260	€ 1,125	€ 895
Average residual holding periods	1 year 11 months 26 days	1 year 8 months 19 days	2 years 10 days
Non-current income tax liabilities	€ 1,733	€ 1,680	€ 1,407	1,733	1,680	1,407
Other non-current liabilities	317	288	323	€ 317	288	323
Tax charge on deemed repatriation attributable to accumulated earnings payable period				8 years
Liability recognized representing the estimated cost				€ 894	974	952
Greater than 12 Months
Provisions and other non-current liabilities [Line Items]
Other non-current liabilities	569	649	635	569	649	635
Evotec
Provisions and other non-current liabilities [Line Items]
Restructuring provision	110	154		€ 110	154
Other environment related provision
Provisions and other non-current liabilities [Line Items]
Identified environmental risks provisions estimated obligation period				30 years
Other provisions, expected utilized amount in 2021				€ 189
Other provisions, expected utilized amount in 2022 through 2025				234
Uncertainties over income tax treatments
Provisions and other non-current liabilities [Line Items]
Non-current income tax liabilities	1,164	1,031	772	1,164	1,031	772
France
Provisions and other non-current liabilities [Line Items]
Employee termination benefits	€ 889	694	623	€ 889	694	623
France | Evotec
Provisions and other non-current liabilities [Line Items]
Restructuring provision		22	68		22	68
USA
Provisions and other non-current liabilities [Line Items]
Number of types of defined-benefit plan | plan				2
UK
Provisions and other non-current liabilities [Line Items]
Retirement age | age				65
Notional retirement age | age				60
UK | Bottom of range
Provisions and other non-current liabilities [Line Items]
Vesting right percentage				1.25%
UK | Top of range
Provisions and other non-current liabilities [Line Items]
Vesting right percentage				1.50%
Lump-sum retirement benefit plans | France
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	41.00%			41.00%
Defined benefit pension plans | France
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	59.00%			59.00%
Defined benefit pension plans | USA | Qualified defined benefit pension plans
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	53.00%			53.00%
Defined benefit pension plans | USA | Non qualified defined benefit pension plans
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	12.00%			12.00%
Defined benefit pension plans | UK
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	100.00%			100.00%
Top-up defined-benefit pension plan | Germany
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	65.00%			65.00%
Sanofi-Aventis Plus | Germany
Provisions and other non-current liabilities [Line Items]
Employer's contribution percentage				15.00%
Multi-employer plan (Pensionskasses) | Germany
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	22.00%			22.00%
Employee termination benefits	€ 773	694	673	€ 773	694	673
Healthcare Cover And Life Insurance | USA
Provisions and other non-current liabilities [Line Items]
Pension obligation, percentage to defined benefit liability	35.00%			35.00%
Employee termination benefits	€ 734			€ 734
Healthcare Cover And Life Insurance | USA | Plan assets
Provisions and other non-current liabilities [Line Items]
Pension obligations, percentage to plan assets	4.00%			4.00%
Net amount shown in the balance sheet at end of period	€ 44			€ 44
Pensions and other post-employment benefits
Provisions and other non-current liabilities [Line Items]
Employee termination benefits	12,677	13,322	12,055	12,677	13,322	12,055
Net amount shown in the balance sheet at end of period	3,320	3,672	3,445	3,320	3,672	3,445
Total expense for pension and other postemplyment benefits				76	88	285
Pensions and other post-employment benefits | Plan assets
Provisions and other non-current liabilities [Line Items]
Net amount shown in the balance sheet at end of period	(9,358)	(9,651)	(8,610)	(9,358)	(9,651)	(8,610)	€ (9,106)
Pensions and other post-employment benefits | France
Provisions and other non-current liabilities [Line Items]
Employee termination benefits	1,999	2,077	2,091	1,999	2,077	2,091
Net amount shown in the balance sheet at end of period	1,093	1,121	1,160	1,093	1,121	1,160
Pensions and other post-employment benefits | Germany
Provisions and other non-current liabilities [Line Items]
Employee termination benefits	3,580	3,470	3,262	3,580	3,470	3,262
Net amount shown in the balance sheet at end of period	919	954	1,045	919	954	1,045
Pensions and other post-employment benefits | USA
Provisions and other non-current liabilities [Line Items]
Employee termination benefits	2,091	2,948	2,597	2,091	2,948	2,597
Net amount shown in the balance sheet at end of period	1,014	1,174	975	1,014	1,174	975
Pensions and other post-employment benefits | UK
Provisions and other non-current liabilities [Line Items]
Employee termination benefits	3,561	3,388	2,858	3,561	3,388	2,858
Net amount shown in the balance sheet at end of period	€ 25	€ 130	€ (4)	€ 25	€ 130	€ (4)

Provisions, income tax liabil_6

Provisions, income tax liabilities and other liabilities - Summary of Financial and Demographic Assumptions (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [line items]
Weighted average duration of defined benefit obligation	10 years
France
Disclosure of defined benefit plans [line items]
General inflation rate	1.45%	1.30%	1.50%
Pension benefit indexation, top of range	1.45%
Healthcare cost inflation rate, top of range	0.00%	2.00%	2.00%
Retirement age, bottom of range	62 years	62 years	62 years
Retirement age, top of range	67 years	67 years	67 years
Weighted average duration of defined benefit obligation	13 years	13 years	13 years
Germany
Disclosure of defined benefit plans [line items]
General inflation rate	1.45%	1.30%	1.50%
Pension benefit indexation, top of range	1.45%	1.30%	1.50%
Healthcare cost inflation rate, top of range	0.00%	0.00%	0.00%
Retirement age, top of range	62 years	62 years	62 years
Weighted average duration of defined benefit obligation	16 years	15 years	15 years
USA
Disclosure of defined benefit plans [line items]
Discount rate	2.40%	3.00%	4.00%
General inflation rate	2.00%	2.00%	2.00%
Pension benefit indexation, top of range	0.00%	0.00%	0.00%
Healthcare cost inflation rate, top of range		5.52%	5.66%
Retirement age, bottom of range	55 years	55 years	55 years
Retirement age, top of range	70 years	70 years	70 years
Weighted average duration of defined benefit obligation	16 years	14 years	13 years
UK
Disclosure of defined benefit plans [line items]
Discount rate	1.35%	2.00%	3.00%
General inflation rate	2.95%	2.85%	3.10%
Pension benefit indexation, top of range	2.85%	2.80%	3.00%
Healthcare cost inflation rate, top of range	4.45%	4.35%	1.50%
Retirement age, bottom of range	60 years	60 years	60 years
Retirement age, top of range	65 years	65 years	65 years
Weighted average duration of defined benefit obligation	18 years	17 years	17 years
Spread relative to general inflation rate	1.50%
Minimum plan 2
Disclosure of defined benefit plans [line items]
Weighted average duration of defined benefit obligation	7 years
Maximum plan 2
Disclosure of defined benefit plans [line items]
Weighted average duration of defined benefit obligation	10 years
Bottom of range
Disclosure of defined benefit plans [line items]
Weighted average duration of defined benefit obligation	0 years
Bottom of range | France
Disclosure of defined benefit plans [line items]
Discount rate	0.00%	0.25%	1.25%
Pension benefit indexation, top of range		1.25%	1.25%
Bottom of range | Germany
Disclosure of defined benefit plans [line items]
Discount rate	0.00%	0.25%	1.25%
Bottom of range | USA
Disclosure of defined benefit plans [line items]
Healthcare cost inflation rate, top of range	3.50%
Top of range
Disclosure of defined benefit plans [line items]
Weighted average duration of defined benefit obligation	7 years
Top of range | France
Disclosure of defined benefit plans [line items]
Discount rate	0.55%	0.75%	1.75%
Pension benefit indexation, top of range		2.25%	2.25%
Top of range | Germany
Disclosure of defined benefit plans [line items]
Discount rate	0.55%	0.75%	1.75%
Top of range | USA
Disclosure of defined benefit plans [line items]
Healthcare cost inflation rate, top of range	4.50%

Provisions, income tax liabil_7

Provisions, income tax liabilities and other liabilities - Summary of Weighted Average Duration of Obligation for Pensions and Other Long-term Benefits in Principal Countries (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [line items]
Weighted average duration in main countries	10 years
France
Disclosure of defined benefit plans [line items]
Weighted average duration in main countries	13 years	13 years	13 years
Germany
Disclosure of defined benefit plans [line items]
Weighted average duration in main countries	16 years	15 years	15 years
USA
Disclosure of defined benefit plans [line items]
Weighted average duration in main countries	16 years	14 years	13 years
UK
Disclosure of defined benefit plans [line items]
Weighted average duration in main countries	18 years	17 years	17 years

Provisions, income tax liabil_8

Provisions, income tax liabilities and other liabilities - Summary of Sensitivity for Pensions and Other Post-Employment Benefits to Changes in Key Actuarial Assumptions (Details) € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)
Discount rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Possible decrease in actuarial assumption	(0.50%)
General inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Possible increase in actuarial assumption	0.50%
Pension benefit indexation
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Possible increase in actuarial assumption	0.50%
Healthcare cost inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Possible increase in actuarial assumption	0.50%
Mortality table
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Possible increase in mortality table (in years)	1 year
France | Discount rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	€ 140
France | General inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	64
France | Pension benefit indexation
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	71
France | Healthcare cost inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	0
France | Mortality table
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	41
Germany | Discount rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	272
Germany | General inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	377
Germany | Pension benefit indexation
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	367
Germany | Healthcare cost inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	0
Germany | Mortality table
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	83
USA | Discount rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	171
USA | General inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	1
USA | Pension benefit indexation
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	0
USA | Healthcare cost inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	14
USA | Mortality table
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	55
UK | Discount rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	337
UK | General inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	216
UK | Pension benefit indexation
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	160
UK | Healthcare cost inflation rate
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	0
UK | Mortality table
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Measurement of defined-benefit obligation	€ 154

Provisions, income tax liabil_9

Provisions, income tax liabilities and other liabilities - Reconciliation of Net Amount Recognized in Respect of Pension and Other Post-employment Benefit Plans (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of net defined benefit liability (asset) [line items]
Actuarial losses/(gains) due to changes in financial assumptions	€ (268)	€ (382)	€ 201
Pre-funded obligations (see Note D.7.)	(177)	(155)	(77)
Obligations provided for	7,219	7,353	6,883	€ 7,198
Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Beginning of period	3,672	3,445
Current service cost	218	199	231
Interest (income)/cost	57	83	70
Plan amendments, curtailments or settlements not specified in the terms of the plan	(206)	(195)	(18)
Administration costs and taxes paid during the period	14	7	8
Contributions from plan members	7	6	6
Net obligation	3,319	3,671	3,445
Pre-funded obligations (see Note D.7.)	(177)	(155)	(77)
Expense/(gain) recognized directly in profit or loss	76	88	285
End of period	3,320	3,672	3,445
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	267	377	(201)
Expense/(gain) for the period	343	465	84
Pensions and other post-employment benefits | Present value of defined benefit obligation
Disclosure of net defined benefit liability (asset) [line items]
Beginning of period	13,322	12,055	13,012
Current service cost	218	199	231
Interest (income)/cost	194	293	260
Actuarial losses/(gains) due to changes in demographic assumptions	41	(61)	204
Actuarial losses/(gains) due to changes in financial assumptions	946	1,481	(841)
Actuarial losses/(gains) due to experience adjustments	(24)	(119)	(14)
Plan amendments, curtailments or settlements not specified in the terms of the plan	(945)	(259)	(96)
Plan settlements specified in the terms of the plan	75	78	83
Benefits paid	(545)	(504)	(647)
Changes in scope of consolidation and transfers	(12)	13	(46)
Currency translation differences	(443)	302	75
End of period	12,677	13,322	12,055
Pensions and other post-employment benefits | Plan assets
Disclosure of net defined benefit liability (asset) [line items]
Beginning of period	(9,651)	(8,610)	(9,106)
Interest (income)/cost	(138)	(211)	(190)
Plan amendments, curtailments or settlements not specified in the terms of the plan	(739)	(64)	(78)
Plan settlements specified in the terms of the plan	75	78	83
Changes in scope of consolidation and transfers	0	0	6
Currency translation differences	326	(267)	(39)
Difference between actual return and interest income on plan assets	696	926	(450)
Administration costs and taxes paid during the period	(14)	(7)	(8)
Contributions from plan members	6	6	6
Employer’s contributions	490	250	392
Benefits paid	(469)	(470)	(510)
End of period	(9,358)	(9,651)	(8,610)
Pensions and other post-employment benefits | Effect of asset ceiling
Disclosure of net defined benefit liability (asset) [line items]
Beginning of period	1	0
End of period	1	1	0
Provisions for pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Obligations provided for	3,497	3,827	3,522	€ 3,959
Provisions for pensions and other post-employment benefits | Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Obligations provided for	€ 3,497	€ 3,827	€ 3,522

Provisions, income tax liabi_10

Provisions, income tax liabilities and other liabilities - Net Liability in Respect of Pension Plans and Other Post-employment Benefits by Geographical Region (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	€ 1,260	€ 1,125	€ 895
Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	12,677	13,322	12,055
Fair value of plan assets	9,358	9,651	8,610
Effect of asset ceiling	1	1
Net amount shown in the balance sheet at end of period	3,320	3,672	3,445
France
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	889	694	623
France | Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	1,999	2,077	2,091
Fair value of plan assets	906	956	931
Effect of asset ceiling	0	0
Net amount shown in the balance sheet at end of period	1,093	1,121	1,160
Germany | Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	3,580	3,470	3,262
Fair value of plan assets	2,661	2,516	2,217
Effect of asset ceiling	0	0
Net amount shown in the balance sheet at end of period	919	954	1,045
USA | Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	2,091	2,948	2,597
Fair value of plan assets	1,077	1,774	1,622
Effect of asset ceiling	0	0
Net amount shown in the balance sheet at end of period	1,014	1,174	975
UK | Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	3,561	3,388	2,858
Fair value of plan assets	3,536	3,258	2,862
Effect of asset ceiling	0	0
Net amount shown in the balance sheet at end of period	25	130	(4)
Other
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	371	431	272
Other | Pensions and other post-employment benefits
Disclosure of net defined benefit liability (asset) [line items]
Measurement of obligation	1,446	1,439	1,247
Fair value of plan assets	1,178	1,147	978
Effect of asset ceiling	1	1
Net amount shown in the balance sheet at end of period	€ 269	€ 293	€ 269

Provisions, income tax liabi_11

Provisions, income tax liabilities and other liabilities - Fair Value of Plans Assets relating to Pension Plans and Other Post-employment Plans (Details)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of fair value of plan assets [line items]
Securities quoted in an active market	94.80%	87.40%	99.20%
Other securities	5.20%	12.60%	0.80%
Total	100.00%	100.00%	100.00%
Cash and cash equivalents
Disclosure of fair value of plan assets [line items]
Securities quoted in an active market	3.50%	1.80%	1.40%
Equity instruments
Disclosure of fair value of plan assets [line items]
Securities quoted in an active market	24.80%	22.60%	22.30%
Bonds and similar instruments
Disclosure of fair value of plan assets [line items]
Securities quoted in an active market	59.90%	55.80%	66.50%
Real estate
Disclosure of fair value of plan assets [line items]
Securities quoted in an active market	3.40%	3.80%	4.20%
Commodities
Disclosure of fair value of plan assets [line items]
Securities quoted in an active market	0.90%	0.90%	0.70%
Other
Disclosure of fair value of plan assets [line items]
Securities quoted in an active market	2.30%	2.50%	4.10%
Hedge funds
Disclosure of fair value of plan assets [line items]
Other securities	0.40%	0.00%	0.00%
Insurance policies
Disclosure of fair value of plan assets [line items]
Other securities	4.80%	12.60%	0.80%

Provisions, income tax liabi_12

Provisions, income tax liabilities and other liabilities - Service Cost for Pension and Other post-employment Benefit Plans, by Geographical Region (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
France
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	€ 24	€ 89	€ (155)
Germany
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	121	(5)	(13)
USA
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	22	148	(38)
UK
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	115	133	7
Pensions and other post-employment benefits
Disclosure of defined benefit plans [line items]
Current service cost	218	199	231
(Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan	(206)	(195)	(18)
Net interest cost/(income) including administration costs and taxes paid during the period	71	90	78
Contributions from plan members	(7)	(6)	(6)
Expense/(gain) recognized directly in profit or loss	76	88	285
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(267)	(377)	201
Expense/(gain) for the period	343	465	84
Pensions and other post-employment benefits | France
Disclosure of defined benefit plans [line items]
Current service cost	62	62	78
(Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan	(94)	(193)	(5)
Net interest cost/(income) including administration costs and taxes paid during the period	9	20	17
Contributions from plan members	0	0	0
Expense/(gain) recognized directly in profit or loss	(23)	(111)	90
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(24)	(89)	155
Expense/(gain) for the period	1	(22)	(65)
Pensions and other post-employment benefits | Germany
Disclosure of defined benefit plans [line items]
Current service cost	49	42	51
(Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan	10	13	(20)
Net interest cost/(income) including administration costs and taxes paid during the period	13	17	12
Contributions from plan members	0	0	0
Expense/(gain) recognized directly in profit or loss	72	72	43
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(121)	4	13
Expense/(gain) for the period	193	68	30
Pensions and other post-employment benefits | USA
Disclosure of defined benefit plans [line items]
Current service cost	51	42	46
(Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan	(123)	(12)	3
Net interest cost/(income) including administration costs and taxes paid during the period	34	40	35
Contributions from plan members	0	0	0
Expense/(gain) recognized directly in profit or loss	(38)	70	84
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(22)	(148)	38
Expense/(gain) for the period	(16)	218	46
Pensions and other post-employment benefits | UK
Disclosure of defined benefit plans [line items]
Current service cost	0	0	0
(Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan	0	(2)	5
Net interest cost/(income) including administration costs and taxes paid during the period	5	2	4
Contributions from plan members	0	0	0
Expense/(gain) recognized directly in profit or loss	5	0	9
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(115)	(133)	(7)
Expense/(gain) for the period	120	133	16
Pensions and other post-employment benefits | Other
Disclosure of defined benefit plans [line items]
Current service cost	56	53	56
(Gains)/losses related to plan amendments, curtailments or settlements not specified in the terms of the plan	1	(1)	(1)
Net interest cost/(income) including administration costs and taxes paid during the period	10	11	10
Contributions from plan members	(7)	(6)	(6)
Expense/(gain) recognized directly in profit or loss	60	57	59
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	15	(11)	2
Expense/(gain) for the period	€ 45	€ 68	€ 57

Provisions, income tax liabi_13

Provisions, income tax liabilities and other liabilities - Remeasurement of Net Defined-benefit (Asset)/Liability (Actuarial Gains and Losses) (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [line items]
Gains/(losses) on financial assumptions	€ 268	€ 382	€ (201)
France
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(24)	(89)	155
Gains/(losses) on experience adjustments	26	149	21
Gains/(losses) on demographic assumptions	20	0	(7)
Gains/(losses) on financial assumptions	(70)	(238)	141
Germany
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(121)	5	13
Gains/(losses) on experience adjustments	76	331	(154)
Gains/(losses) on demographic assumptions	0	0	(67)
Gains/(losses) on financial assumptions	(197)	(326)	234
USA
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(22)	(148)	38
Gains/(losses) on experience adjustments	214	210	(131)
Gains/(losses) on demographic assumptions	(42)	0	7
Gains/(losses) on financial assumptions	(194)	(358)	162
UK
Disclosure of defined benefit plans [line items]
Remeasurement of net defined-benefit (asset)/liability (actuarial gains and losses)	(115)	(133)	(7)
Gains/(losses) on experience adjustments	341	242	(118)
Gains/(losses) on demographic assumptions	(14)	63	(144)
Gains/(losses) on financial assumptions	€ (442)	€ (438)	€ 255

Provisions, income tax liabi_14

Provisions, income tax liabilities and other liabilities - Summary of Net Pre-tax Actuarial Loss (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Net pre-tax actuarial loss	€ (3,471)	€ (3,207)	€ (2,834)

Provisions, income tax liabi_15

Provisions, income tax liabilities and other liabilities - Summary of Present Value of Pension and Other Post Employment Benefits (Details) - Pensions and other post-employment benefits - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of net defined benefit liability (asset) [line items]
Net defined benefit liability (asset)	€ 3,320	€ 3,672	€ 3,445
Present value of defined benefit obligation
Disclosure of net defined benefit liability (asset) [line items]
Net defined benefit liability (asset)	12,677	13,322	12,055	€ 13,012
Wholly or partly funded defined benefit plans | Present value of defined benefit obligation
Disclosure of net defined benefit liability (asset) [line items]
Net defined benefit liability (asset)	11,543	12,057	10,995
Wholly unfunded defined benefit plans | Present value of defined benefit obligation
Disclosure of net defined benefit liability (asset) [line items]
Net defined benefit liability (asset)	€ 1,134	€ 1,265	€ 1,060

Provisions, income tax liabi_16

Provisions, income tax liabilities and other liabilities - Total Expense for Pensions and Other Post-employment Benefits Allocated between Income Statement (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [line items]
Cost of sales	€ 12,157	€ 11,976	€ 11,435
Research and development expenses	5,529	6,018	5,894
Selling and general expenses	9,390	9,883	9,859
Other operating (income)/expenses, net	926	633	221
Restructuring costs	1,064	1,062	1,480
Financial expenses	390	444	435
Pensions and other post-employment benefits
Disclosure of defined benefit plans [line items]
Cost of sales	75	46	67
Research and development expenses	62	25	77
Selling and general expenses	(34)	(22)	84
Other operating (income)/expenses, net	(18)	(3)	(21)
Restructuring costs	(66)	(41)	8
Financial expenses	57	83	70
Total	€ 76	€ 88	€ 285

Provisions, income tax liabi_17

Provisions, income tax liabilities and other liabilities - Estimated Amounts of Employer's Contributions to Plan Assets (Details) - Less than 1 year € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)
Disclosure of fair value of plan assets [line items]
Estimate of contributions expected to be paid to plan for next annual reporting period	€ 42
France
Disclosure of fair value of plan assets [line items]
Estimate of contributions expected to be paid to plan for next annual reporting period	0
Germany
Disclosure of fair value of plan assets [line items]
Estimate of contributions expected to be paid to plan for next annual reporting period	0
USA
Disclosure of fair value of plan assets [line items]
Estimate of contributions expected to be paid to plan for next annual reporting period	0
UK
Disclosure of fair value of plan assets [line items]
Estimate of contributions expected to be paid to plan for next annual reporting period	3
Other
Disclosure of fair value of plan assets [line items]
Estimate of contributions expected to be paid to plan for next annual reporting period	€ 39

Provisions, income tax liabi_18

Provisions, income tax liabilities and other liabilities - Expected Timing of Benefit Payments under Pension and Other Post-employment Benefit Plans (Details) € in Millions	Dec. 31, 2020EUR (€)
2021
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	€ 607
2022
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	517
2023
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	539
2024
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	564
2025
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	560
2026 and later
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	3,066
France | 2021
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	145
France | 2022
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	64
France | 2023
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	74
France | 2024
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	84
France | 2025
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	80
France | 2026 and later
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	529
Germany | 2021
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	186
Germany | 2022
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	190
Germany | 2023
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	195
Germany | 2024
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	199
Germany | 2025
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	203
Germany | 2026 and later
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	1,024
USA | 2021
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	95
USA | 2022
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	88
USA | 2023
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	88
USA | 2024
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	91
USA | 2025
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	85
USA | 2026 and later
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	439
UK | 2021
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	119
UK | 2022
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	122
UK | 2023
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	126
UK | 2024
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	130
UK | 2025
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	134
UK | 2026 and later
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	734
Other | 2021
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	62
Other | 2022
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	53
Other | 2023
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	56
Other | 2024
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	60
Other | 2025
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	58
Other | 2026 and later
Disclosure of defined benefit plans [line items]
Estimated future benefit payments under pension and other post-employment benefit plans	€ 340

Provisions, income tax liabi_19

Provisions, income tax liabilities and other liabilities - Timing of Future Payments in Respect of Unfunded Pension and Other Post-employment Benefit Plans (Details) € in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)
Disclosure of defined benefit plans [line items]
Estimated payments	€ 1,134
Less than 1 year
Disclosure of defined benefit plans [line items]
Estimated payments	61
From 1 to 3 years
Disclosure of defined benefit plans [line items]
Estimated payments	99
From 3 to 5 years
Disclosure of defined benefit plans [line items]
Estimated payments	102
More than 5 years
Disclosure of defined benefit plans [line items]
Estimated payments	€ 872

Provisions, income tax liabi_20

Provisions, income tax liabilities and other liabilities - Movements in Restructuring Provisions Classified in Non-current and Current Liabilities (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Restructuring Provisions [line items]
Balance, beginning of period	€ 7,641	€ 7,206
Classified in current liabilities	631	790	€ 940
Provisions utilized	(793)	(522)	(793)
Transfers	(421)	(154)	(289)
Currency translation differences	(214)	50	50
Balance, end of period	7,536	7,641	7,206
Of which:
Classified in current liabilities	631	790	940
Restructuring Provision
Disclosure of Restructuring Provisions [line items]
Balance, beginning of period	1,390	1,572	1,086
Classified in non-current liabilities	600	632	514
Classified in current liabilities	631	790	940	€ 572
Change in provisions recognized in profit or loss for the period	767	760	1,035
Provisions utilized	(663)	(897)	(605)
Transfers	20	(51)	54
Unwinding of discount	1	3	0
Currency translation differences	(16)	3	2
Balance, end of period	1,499	1,390	1,572
Of which:
Classified in non-current liabilities	868	600	632
Classified in current liabilities	€ 631	€ 790	€ 940	€ 572

Provisions, income tax liabi_21

Provisions, income tax liabilities and other liabilities - Timing of Future Termination Benefit Payments (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [line items]
Employee termination benefits	€ 1,260	€ 1,125	€ 895
Less than 1 year
Disclosure of defined benefit plans [line items]
Employee termination benefits	490	657	489
From 1 to 3 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	606	347	304
From 3 to 5 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	142	116	77
More than 5 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	22	5	25
France
Disclosure of defined benefit plans [line items]
Employee termination benefits	889	694	623
France | Less than 1 year
Disclosure of defined benefit plans [line items]
Employee termination benefits	295	314	302
France | From 1 to 3 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	457	268	242
France | From 3 to 5 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	124	110	71
France | More than 5 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	13	2	8
Other
Disclosure of defined benefit plans [line items]
Employee termination benefits	371	431	272
Other | Less than 1 year
Disclosure of defined benefit plans [line items]
Employee termination benefits	195	343	187
Other | From 1 to 3 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	149	79	62
Other | From 3 to 5 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	18	6	6
Other | More than 5 years
Disclosure of defined benefit plans [line items]
Employee termination benefits	€ 9	€ 3	€ 17

Provisions, income tax liabi_22

Provisions, income tax liabilities and other liabilities - Summary of Other Provisions (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of other provisions [abstract]
Environmental risks	€ 713	€ 737	€ 680
Product liability risks, litigation and other	1,262	1,334	1,288
Total	€ 1,975	€ 2,071	€ 1,968

Provisions, income tax liabi_23

Provisions, income tax liabilities and other liabilities - Current Provisions and Other Current Liabilities (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Taxes payable, other than corporate income taxes	€ 347	€ 361	€ 393
Employee-related liabilities	2,042	1,978	1,989
Classified in current liabilities	631	790	940
Interest rate derivatives (see Note D.20.)	0	2	0
Currency derivatives (see Note D.20.)	205	87	90
Amounts payable for acquisitions of non-current assets	467	413	497
Contract liabilities	252	0	0
Other current liabilities	6,188	6,072	5,060
Total	€ 10,132	9,703	€ 8,969
Litigation amount payable		€ 315

Provisions, income tax liabi_24

Provisions, income tax liabilities and other liabilities - Summary of Lease Liabilities (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019
Provisions and other non-current liabilities [Line Items]
Lease liability total	€ 1,163	€ 1,248
Effect of discounting	(148)	(218)
From 1 to 3 years
Provisions and other non-current liabilities [Line Items]
Lease liability total	357	422
From 3 to 5 years
Provisions and other non-current liabilities [Line Items]
Lease liability total	225	232
More than 5 years
Provisions and other non-current liabilities [Line Items]
Lease liability total	€ 482	€ 540

Derivative financial instrume_3

Derivative financial instruments and market risks - Summary of Fair Value of Derivative Instruments (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Credit Risk Exposure [Line Items]
Non-current assets	€ 24	€ 37	€ 19
Current assets	58
Total assets	82
Non-current liabilities	(92)	(10)	(7)
Current liabilities	(205)
Total liabilities	(297)
Market value	(215)	126	86
Currency derivatives
Disclosure of Credit Risk Exposure [Line Items]
Non-current assets	0
Current assets	58
Total assets	58
Non-current liabilities	(62)
Current liabilities	(205)
Total liabilities	(267)
Market value	(209)	103	44
operating
Disclosure of Credit Risk Exposure [Line Items]
Non-current assets	0
Current assets	26
Total assets	26
Non-current liabilities	0
Current liabilities	(19)
Total liabilities	(19)
Market value	7	(15)	7
financial
Disclosure of Credit Risk Exposure [Line Items]
Non-current assets	0
Current assets	32
Total assets	32
Non-current liabilities	(62)
Current liabilities	(186)
Total liabilities	(248)
Market value	(216)	118	37
Interest rate derivatives
Disclosure of Credit Risk Exposure [Line Items]
Non-current assets	24
Current assets	0
Total assets	24
Non-current liabilities	(4)
Current liabilities	0
Total liabilities	(4)
Market value	20	27	42
Equity derivatives
Disclosure of Credit Risk Exposure [Line Items]
Non-current assets	0
Current assets	0
Total assets	0
Non-current liabilities	(26)
Current liabilities	0
Total liabilities	(26)
Market value	€ (26)	€ (4)

Derivative financial instrume_4

Derivative financial instruments and market risks - Summary of Operating Currency Hedging Instruments (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Notional amount
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	€ 5,409	€ 5,207	€ 6,038
Notional amount | Forward currency sales
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	3,477	3,372	4,002
Notional amount | Forward currency sales in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1,367	1,186	1,723
Notional amount | Forward currency sales in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	521	447	451
Notional amount | Forward currency sales in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	287	410	652
Notional amount | Forward currency sales in Japanese Yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	143
Notional amount | Forward currency sales In Mexican Peso
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	121
Notional amount | Forward currency purchases
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1,932	1,835	2,036
Notional amount | Forward currency purchases in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	580	602	514
Notional amount | Forward currency purchases in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	571	525	500
Notional amount | Forward currency purchases in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	286	130	163
Notional amount | Forward currency purchases In Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	61	49
Notional amount | Forward currency purchases In Japanese yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	55		197
Notional amount | Forward currency sales in Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		184	88
Notional amount | Forward currency sales in Saudi Riyal
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		133	100
Notional amount | Forward currency purchases in Hungarian Florint
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		60
Notional amount | Forward currency purchases in Canadian Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place			106
Notional amount | Cash flow hedges
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency sales
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency sales in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency sales in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency sales in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency sales in Japanese Yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Notional amount | Cash flow hedges | Forward currency sales In Mexican Peso
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Notional amount | Cash flow hedges | Forward currency purchases
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency purchases in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency purchases in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency purchases in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Notional amount | Cash flow hedges | Forward currency purchases In Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0
Notional amount | Cash flow hedges | Forward currency purchases In Japanese yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0		0
Notional amount | Cash flow hedges | Forward currency sales in Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0	0
Notional amount | Cash flow hedges | Forward currency sales in Saudi Riyal
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0	0
Notional amount | Cash flow hedges | Forward currency purchases in Hungarian Florint
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0
Notional amount | Cash flow hedges | Forward currency purchases in Canadian Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place			0
Notional amount | Not eligible for hedge accounting
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	5,409	5,207	6,038
Notional amount | Not eligible for hedge accounting | Forward currency sales
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	3,477	3,372	4,002
Notional amount | Not eligible for hedge accounting | Forward currency sales in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1,367	1,186	1,723
Notional amount | Not eligible for hedge accounting | Forward currency sales in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	521	447	451
Notional amount | Not eligible for hedge accounting | Forward currency sales in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	287	410	652
Notional amount | Not eligible for hedge accounting | Forward currency sales in Japanese Yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	143
Notional amount | Not eligible for hedge accounting | Forward currency sales In Mexican Peso
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	121
Notional amount | Not eligible for hedge accounting | Forward currency purchases
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1,932	1,835	2,036
Notional amount | Not eligible for hedge accounting | Forward currency purchases in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	580	602	514
Notional amount | Not eligible for hedge accounting | Forward currency purchases in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	571	525	500
Notional amount | Not eligible for hedge accounting | Forward currency purchases in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	286	130	163
Notional amount | Not eligible for hedge accounting | Forward currency purchases In Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	61	49
Notional amount | Not eligible for hedge accounting | Forward currency purchases In Japanese yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	55		197
Notional amount | Not eligible for hedge accounting | Forward currency sales in Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		184	88
Notional amount | Not eligible for hedge accounting | Forward currency sales in Saudi Riyal
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		133	100
Notional amount | Not eligible for hedge accounting | Forward currency purchases in Hungarian Florint
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		60
Notional amount | Not eligible for hedge accounting | Forward currency purchases in Canadian Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place			106
Fair value
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	7	(15)	7
Fair value | Forward currency sales
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	7	(10)	0
Fair value | Forward currency sales in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	10	3	(7)
Fair value | Forward currency sales in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	2	0	(1)
Fair value | Forward currency sales in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	(1)	0	1
Fair value | Forward currency sales in Japanese Yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1
Fair value | Forward currency sales In Mexican Peso
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Fair value | Forward currency purchases
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	(5)	7
Fair value | Forward currency purchases in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	(1)	(6)	8
Fair value | Forward currency purchases in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	(1)	1	1
Fair value | Forward currency purchases in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1	0	(1)
Fair value | Forward currency purchases In Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0
Fair value | Forward currency purchases In Japanese yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0		3
Fair value | Forward currency sales in Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		(3)	5
Fair value | Forward currency sales in Saudi Riyal
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		1	1
Fair value | Forward currency purchases in Hungarian Florint
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0
Fair value | Forward currency purchases in Canadian Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place			(2)
Fair value | Cash flow hedges
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency sales
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency sales in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency sales in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency sales in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency sales in Japanese Yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Fair value | Cash flow hedges | Forward currency sales In Mexican Peso
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Fair value | Cash flow hedges | Forward currency purchases
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency purchases in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency purchases in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency purchases in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Fair value | Cash flow hedges | Forward currency purchases In Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0
Fair value | Cash flow hedges | Forward currency purchases In Japanese yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0		0
Fair value | Cash flow hedges | Forward currency sales in Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0	0
Fair value | Cash flow hedges | Forward currency sales in Saudi Riyal
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0	0
Fair value | Cash flow hedges | Forward currency purchases in Hungarian Florint
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0
Fair value | Cash flow hedges | Forward currency purchases in Canadian Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place			0
Fair value | Not eligible for hedge accounting
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	7	(15)	7
Fair value | Not eligible for hedge accounting | Forward currency sales
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	7	(10)	0
Fair value | Not eligible for hedge accounting | Forward currency sales in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	10	3	(7)
Fair value | Not eligible for hedge accounting | Forward currency sales in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	2	0	(1)
Fair value | Not eligible for hedge accounting | Forward currency sales in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	(1)	0	1
Fair value | Not eligible for hedge accounting | Forward currency sales in Japanese Yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1
Fair value | Not eligible for hedge accounting | Forward currency sales In Mexican Peso
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Fair value | Not eligible for hedge accounting | Forward currency purchases
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	(5)	7
Fair value | Not eligible for hedge accounting | Forward currency purchases in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	(1)	(6)	8
Fair value | Not eligible for hedge accounting | Forward currency purchases in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	(1)	1	1
Fair value | Not eligible for hedge accounting | Forward currency purchases in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	1	0	(1)
Fair value | Not eligible for hedge accounting | Forward currency purchases In Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0
Fair value | Not eligible for hedge accounting | Forward currency purchases In Japanese yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0		3
Fair value | Not eligible for hedge accounting | Forward currency sales in Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		(3)	5
Fair value | Not eligible for hedge accounting | Forward currency sales in Saudi Riyal
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		1	1
Fair value | Not eligible for hedge accounting | Forward currency purchases in Hungarian Florint
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0
Fair value | Not eligible for hedge accounting | Forward currency purchases in Canadian Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place			(2)
Of which recognized in equity | Cash flow hedges
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency sales
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency sales in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency sales in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency sales in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency sales in Japanese Yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Of which recognized in equity | Cash flow hedges | Forward currency sales In Mexican Peso
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0
Of which recognized in equity | Cash flow hedges | Forward currency purchases
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency purchases in USD
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency purchases in Singapore Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency purchases in Chinese Yuan Renminbi
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0	0
Of which recognized in equity | Cash flow hedges | Forward currency purchases In Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	0	0
Of which recognized in equity | Cash flow hedges | Forward currency purchases In Japanese yen
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place	€ 0		0
Of which recognized in equity | Cash flow hedges | Forward currency sales in Russian Rouble
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0	0
Of which recognized in equity | Cash flow hedges | Forward currency sales in Saudi Riyal
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		0	0
Of which recognized in equity | Cash flow hedges | Forward currency purchases in Hungarian Florint
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place		€ 0
Of which recognized in equity | Cash flow hedges | Forward currency purchases in Canadian Dollar
Disclosure of Information about Credit Exposures Designated as Measured at Fair Value Through Profit or Loss [Line Items]
Operating currency hedging instruments in place			€ 0

Derivative financial instrume_5

Derivative financial instruments and market risks - Disclosure of Financial Currency Hedging Instruments in Place with Notional Amount Translated (Details) $ in Millions	Dec. 31, 2020EUR (€)	Dec. 31, 2020USD ($)	Apr. 30, 2020EUR (€)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Notional amount of forward sales	€ 19,794,000,000		€ 500,000,000
Derivative financial liabilities	297,000,000
Forward currency sales in USD
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Fair value of forward contracts assets	13,000,000
Forward currency sales in USD | Bioverativ
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Notional amount of forward sales | $		$ 3,615
Forward currency purchases in USD
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Notional amount of forward sales | $		3,000
Derivative financial liabilities	109,000,000
Forward currency purchases in Singapore Dollar
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Notional amount of forward sales | $		2,000
Derivative financial liabilities	22,000,000
Currency swaps in USD to EUR
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Notional amount of forward sales | $		$ 1,000
Derivative financial liabilities	€ 38,000,000
Currency swaps, percentage received	0.22%	0.22%
Currency Swaps, percentage paid	(0.63%)	(0.63%)
Notional amount
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	€ 14,068,000,000			€ 19,490,000,000	€ 15,053,000,000
Notional amount | Forward currency sales
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	5,064,000,000			8,515,000,000	7,762,000,000
Notional amount | Forward currency sales in USD | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	3,721,000,000			6,331,000,000	5,500,000,000
Notional amount | Forward currency sales in Japanese Yen | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	283,000,000			516,000,000	973,000,000
Notional amount | Forward currency sales in Pound Sterling | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	257,000,000			297,000,000	184,000,000
Notional amount | Forward currency purchases
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	9,004,000,000			10,975,000,000	7,291,000,000
Notional amount | Forward currency purchases in USD | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	6,068,000,000			7,363,000,000	4,165,000,000
Notional amount | Forward currency purchases in Singapore Dollar | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	2,250,000,000			2,332,000,000	2,022,000,000
Notional amount | Forward currency purchases in Chinese Yuan Renminbi | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	195,000,000			270,000,000	427,000,000
Fair value
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	(216,000,000)			118,000,000	37,000,000
Fair value | Forward currency sales
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	10,000,000			40,000,000	17,000,000
Fair value | Forward currency sales in USD | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	20,000,000			51,000,000	38,000,000
Fair value | Forward currency sales in Japanese Yen | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	0			(5,000,000)	(24,000,000)
Fair value | Forward currency sales in Pound Sterling | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	(6,000,000)			1,000,000	0
Fair value | Forward currency purchases
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	(226,000,000)			78,000,000	20,000,000
Fair value | Forward currency purchases in USD | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	(200,000,000)			42,000,000	(17,000,000)
Fair value | Forward currency purchases in Singapore Dollar | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	(27,000,000)			32,000,000	33,000,000
Fair value | Forward currency purchases in Chinese Yuan Renminbi | Less than 1 year
Disclosure of Information about Terms and Conditions of Hedging Instruments and How They Affect Future Cash Flows [Line Items]
Financial currency hedging instruments in place	€ 1,000,000			€ 2,000,000	€ 0

Derivative financial instrume_6

Derivative financial instruments and market risks - Disclosure of Instruments (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Notional amount
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	€ 2,699	€ 3,591	€ 4,521
Nominal value of interest rate swaps hedge fixed-rate bonds	5,409	5,207	6,038
Currency and interest rate derivatives	2,699	3,591	4,521
Notional amount | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	2,099	2,545	4,085
Currency and interest rate derivatives	2,099	2,545	4,085
Notional amount | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	600	1,046	436
Nominal value of interest rate swaps hedge fixed-rate bonds	0	0	0
Currency and interest rate derivatives	600	1,046	436
Notional amount | Less than 1 year
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	892	1,550
Currency and interest rate derivatives	0	892	1,550
Notional amount | 1 to 2 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	2,642	0	872
Currency and interest rate derivatives	2,642	0	872
Notional amount | 2 to 3 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	57	2,642
Currency and interest rate derivatives	57	2,642
Notional amount | 2 to 3 years | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Notional amount | 3 to 4 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	57	2,042
Currency and interest rate derivatives	0	57	2,042
Notional amount | 4 to 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	57
Currency and interest rate derivatives	0	0	57
Notional amount | More than 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0
Currency and interest rate derivatives	0	0
Notional amount | More than 5 years | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Fair value
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	20	27	42
Nominal value of interest rate swaps hedge fixed-rate bonds	7	(15)	7
Currency and interest rate derivatives	20	27	42
Fair value | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	19	26	38
Currency and interest rate derivatives	19	26	38
Fair value | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	1	1	5
Nominal value of interest rate swaps hedge fixed-rate bonds	0	0	0
Currency and interest rate derivatives	1	1	5
Of which recognized in equity | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	1	3	7
Nominal value of interest rate swaps hedge fixed-rate bonds	0	0	0
Currency and interest rate derivatives	€ 1	€ 3	€ 7
Interest rate swaps pay capitalized Eonia / receive 0.06%
Disclosure of detailed information about financial instruments [line items]
Interest rate	0.06%	0.06%	0.06%
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	€ 2,000	€ 2,000	€ 2,000
Currency and interest rate derivatives	2,000	2,000	2,000
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	2,000	2,000	2,000
Currency and interest rate derivatives	2,000	2,000	2,000
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | Less than 1 year
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | 1 to 2 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	2,000	0	0
Currency and interest rate derivatives	2,000	0	0
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | 2 to 3 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	2,000	0
Currency and interest rate derivatives	0	2,000	0
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | 3 to 4 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	2,000
Currency and interest rate derivatives	0	0	2,000
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | 4 to 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps pay capitalized Eonia / receive 0.06% | Notional amount | More than 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps pay capitalized Eonia / receive 0.06% | Fair value
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	23	28	15
Currency and interest rate derivatives	23	28	15
Interest rate swaps pay capitalized Eonia / receive 0.06% | Fair value | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	23	28	15
Currency and interest rate derivatives	23	28	15
Interest rate swaps pay capitalized Eonia / receive 0.06% | Fair value | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps pay capitalized Eonia / receive 0.06% | Of which recognized in equity | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	€ 0	€ 0	€ 0
Interest rate swaps pay -0.57% / receivecapitalized Eonia
Disclosure of detailed information about financial instruments [line items]
Interest rate	(0.57%)	(0.57%)
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	€ 600	€ 600
Currency and interest rate derivatives	600	600
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0
Currency and interest rate derivatives	0	0
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	600	600
Currency and interest rate derivatives	600	600
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | Less than 1 year
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0
Currency and interest rate derivatives	0	0
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | 1 to 2 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	600	0
Currency and interest rate derivatives	600	0
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | 2 to 3 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	600
Currency and interest rate derivatives	0	600
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | 3 to 4 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0
Currency and interest rate derivatives	0	0
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | 4 to 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0
Currency and interest rate derivatives	0	0
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Notional amount | More than 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0
Currency and interest rate derivatives	0	0
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Fair value
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	1	3
Currency and interest rate derivatives	1	3
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Fair value | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0
Currency and interest rate derivatives	0	0
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Fair value | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	1	3
Currency and interest rate derivatives	1	3
Interest rate swaps pay -0.57% / receivecapitalized Eonia | Of which recognized in equity | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	1	3
Currency and interest rate derivatives	€ 1	€ 3
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor
Disclosure of detailed information about financial instruments [line items]
Interest rate		1.81%	1.81%
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		€ 446	€ 436
Currency and interest rate derivatives		446	436
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		446	436
Currency and interest rate derivatives		446	436
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | Less than 1 year
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		446	0
Currency and interest rate derivatives		446	0
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | 1 to 2 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	436
Currency and interest rate derivatives		0	436
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | 2 to 3 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | 3 to 4 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | 4 to 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Notional amount | More than 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Fair value
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		(2)	5
Currency and interest rate derivatives		(2)	5
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Fair value | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Fair value | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		(2)	5
Currency and interest rate derivatives		(2)	5
Interest rate swaps pay 1.81% / receive 3-month US dollar Libor | Of which recognized in equity | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	7
Currency and interest rate derivatives		€ 0	€ 7
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor
Disclosure of detailed information about financial instruments [line items]
Interest rate		2.22%	2.22%
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		€ 446	€ 436
Currency and interest rate derivatives		446	436
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		446	436
Currency and interest rate derivatives		446	436
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | Less than 1 year
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		446	0
Currency and interest rate derivatives		446	0
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | 1 to 2 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	436
Currency and interest rate derivatives		0	436
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | 2 to 3 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | 3 to 4 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | 4 to 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Notional amount | More than 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Fair value
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		4	(1)
Currency and interest rate derivatives		4	(1)
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Fair value | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		4	(1)
Currency and interest rate derivatives		4	(1)
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Fair value | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		0	0
Interest rate swaps pay 2.22% / receive 3-month & 6-month US dollar Libor | Of which recognized in equity | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives		0	0
Currency and interest rate derivatives		€ 0	€ 0
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent
Disclosure of detailed information about financial instruments [line items]
Interest rate	1.48%	1.48%	1.48%
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	€ 99	€ 99	€ 99
Nominal value of interest rate swaps hedge fixed-rate bonds	99
Currency and interest rate derivatives	99	99	99
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	99	99	99
Currency and interest rate derivatives	99	99	99
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | Less than 1 year
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | 1 to 2 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	42	0	0
Currency and interest rate derivatives	42	0	0
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | 2 to 3 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	57	42	0
Currency and interest rate derivatives	57	42	0
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | 3 to 4 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	57	42
Currency and interest rate derivatives	0	57	42
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | 4 to 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	57
Currency and interest rate derivatives	0	0	57
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Notional amount | More than 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Fair value
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	(4)	(6)	(6)
Currency and interest rate derivatives	(4)	(6)	(6)
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Fair value | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	(4)	(6)	(6)
Currency and interest rate derivatives	(4)	(6)	(6)
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Fair value | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	0	0	0
Interest rate swaps receive capitalized Eonia / pay 1.48 Percent | Of which recognized in equity | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives	0	0	0
Currency and interest rate derivatives	€ 0	€ 0	€ 0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent
Disclosure of detailed information about financial instruments [line items]
Interest rate			1.58%
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			€ 1,550
Currency and interest rate derivatives			1,550
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			1,550
Currency and interest rate derivatives			1,550
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | Less than 1 year
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			1,550
Currency and interest rate derivatives			1,550
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | 1 to 2 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | 2 to 3 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | 3 to 4 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | 4 to 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Notional amount | More than 5 years
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Fair value
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			30
Currency and interest rate derivatives			30
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Fair value | Derivatives Designated as Fair Value Hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			30
Currency and interest rate derivatives			30
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Fair value | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			0
Interest rate swaps pay capitalized Eonia / receive 1.58 percent | Of which recognized in equity | Cash flow hedges
Disclosure of detailed information about financial instruments [line items]
Currency and interest rate derivatives			0
Currency and interest rate derivatives			€ 0

Derivative financial instrume_7

Derivative financial instruments and market risks - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about financial instruments [line items]
Financial instruments designated as hedging instruments, at fair value	€ 215	€ (126)	€ (86)
Equity derivatives
Disclosure of detailed information about financial instruments [line items]
Shares in derivative instrument (in shares)	593,712
Financial instruments designated as hedging instruments, at fair value	€ 26	€ 4

Derivative financial instrume_8

Derivative financial instruments and market risks - Disclosure of Actual or Potential Effects of Netting Arrangements (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative financial assets
Disclosure of Offsetting of Financial Assets and Liabilities [line items]
Gross carrying amounts before offset	€ 82	€ 225	€ 183
Gross amounts offset (in accordance with IAS 32)	0	0	0
Net amounts as reported in the balance sheet	82	225	183
Net exposure	1	136	102
Derivative financial assets | Effects of other netting arrangements not fulfilling the IAS 32 criteria for offsetting
Disclosure of Offsetting of Financial Assets and Liabilities [line items]
Fair value of financial collateral	0
Financial instruments	(81)	(89)	(81)
Derivative financial liabilities
Disclosure of Offsetting of Financial Assets and Liabilities [line items]
Gross carrying amounts before offset	(297)	(99)	(97)
Gross amounts offset (in accordance with IAS 32)	0	0	0
Net amounts as reported in the balance sheet	(297)	(99)	(97)
Net exposure	(216)	(10)	(16)
Derivative financial liabilities | Effects of other netting arrangements not fulfilling the IAS 32 criteria for offsetting
Disclosure of Offsetting of Financial Assets and Liabilities [line items]
Fair value of financial collateral	0
Financial instruments	€ 81	€ 89	€ 81

Off balance sheet commitments -

Off balance sheet commitments - Summary of Off Balance Sheet Commitments Relating to Operating Activities (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Off Balance Sheet Commitments [Line Items]
Short term leases, low value asset leases and lease contracts committed but not started yet	€ 950	€ 1,067
Irrevocable purchase commitments given	7,153
Irrevocable purchase commitments received	(608)
Research and development license agreements - commitments related to R&D and other commitments	500	784
Research and development license agreements - potential milestone payments	2,456	3,040
Total - net contributions given	10,451
Commitments related to research and development relating to projects in research phase	6,700	6,700
Commitments related to research and development payments contingent upon attainment of sales targets	8,100	10,600
Cumulative development costs incurred	6,600
Commitments related to collaboration, discovery, development and commercialization agreements	3,300	3,200
Less than 1 year
Disclosure Of Off Balance Sheet Commitments [Line Items]
Short term leases, low value asset leases and lease contracts committed but not started yet	39
Irrevocable purchase commitments given	4,072
Irrevocable purchase commitments received	(236)
Research and development license agreements - commitments related to R&D and other commitments	261
Research and development license agreements - potential milestone payments	163
Total - net contributions given	4,299
From 1 to 3 years
Disclosure Of Off Balance Sheet Commitments [Line Items]
Short term leases, low value asset leases and lease contracts committed but not started yet	118
Irrevocable purchase commitments given	1,482
Irrevocable purchase commitments received	(168)
Research and development license agreements - commitments related to R&D and other commitments	217
Research and development license agreements - potential milestone payments	714
Total - net contributions given	2,363
From 3 to 5 years
Disclosure Of Off Balance Sheet Commitments [Line Items]
Short term leases, low value asset leases and lease contracts committed but not started yet	118
Irrevocable purchase commitments given	572
Irrevocable purchase commitments received	(51)
Research and development license agreements - commitments related to R&D and other commitments	10
Research and development license agreements - potential milestone payments	972
Total - net contributions given	1,621
More than 5 years
Disclosure Of Off Balance Sheet Commitments [Line Items]
Short term leases, low value asset leases and lease contracts committed but not started yet	675
Irrevocable purchase commitments given	1,027
Irrevocable purchase commitments received	(153)
Research and development license agreements - commitments related to R&D and other commitments	12
Research and development license agreements - potential milestone payments	607
Total - net contributions given	2,168
Suppliers
Disclosure Of Off Balance Sheet Commitments [Line Items]
Irrevocable purchase commitments given		6,726
Irrevocable purchase commitments received		648
Joint ventures
Disclosure Of Off Balance Sheet Commitments [Line Items]
Irrevocable purchase commitments given	€ 989
Regeneron Pharmaceuticals, INC | Antibodies collaboration agreement
Disclosure Of Off Balance Sheet Commitments [Line Items]
Maximum additional profit-share, in percentage of Regeneron's quarterly profit	10.00%
Percentage of cumulative development costs reimbursed	50.00%
Commitments received for development costs	€ 2,600	2,700
Funded by Sanofi
Disclosure Of Off Balance Sheet Commitments [Line Items]
Cumulative development costs incurred	€ 3,300
Percentage of cumulative development costs	100.00%
Partially Funded
Disclosure Of Off Balance Sheet Commitments [Line Items]
Cumulative development costs incurred	€ 3,300
Percentage of cumulative development costs	80.00%
Partially Funded | Regeneron Pharmaceuticals, INC
Disclosure Of Off Balance Sheet Commitments [Line Items]
Percentage of cumulative development costs	20.00%
Sanofi Belgium
Disclosure Of Off Balance Sheet Commitments [Line Items]
Commitments related to collaboration, discovery, development and commercialization agreements	€ 1,100	1,100
Major business combination | Impact Biomedicines | Celgene Corporation
Disclosure Of Off Balance Sheet Commitments [Line Items]
Commitments related to collaboration, discovery, development and commercialization agreements	€ 500	€ 500

Off balance sheet commitments_2

Off balance sheet commitments - Additional Information (Details) € / shares in Units, € in Millions, shares in Millions, $ in Millions	Jan. 11, 2021USD ($)	Aug. 10, 2020USD ($)	Jul. 20, 2020USD ($)shares	Jun. 11, 2018USD ($)	Feb. 27, 2017EUR (€)	Dec. 31, 2020EUR (€)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)	Dec. 31, 2016	Nov. 02, 2020EUR (€)€ / shares	Feb. 28, 2014
Provisions and other non-current liabilities [Line Items]
Acquisitions of other equity investments | €						€ 137	€ 38	€ 137
Total credit facilities | €						€ 8,000	€ 8,000	€ 8,000
Kiadis
Provisions and other non-current liabilities [Line Items]
Purchase price (in EUR per share) | € / shares										€ 5.45
Purchase price | €										€ 308
Translate Bio
Provisions and other non-current liabilities [Line Items]
Upfront payment			$ 425
Cash payment for collaboration agreement			300,000
Equity investment for collaboration agreement			$ 125,000
Acquisitions of other equity investments (in shares) | shares			4.9
Acquisitions of other equity investments			$ 95
Commitments related to milestone payments for projects under collaboration agreements			1,900
Translate Bio | 2018 Letter Agreement
Provisions and other non-current liabilities [Line Items]
Commitments related to milestone payments for projects under collaboration agreements			$ 450
Translate Bio | Vaccines
Provisions and other non-current liabilities [Line Items]
Transaction value				$ 805
World Health Organization
Provisions and other non-current liabilities [Line Items]
Percentage of pandemic vaccines agreed to transfer											7.50%
Percentage of pandemic vaccines agreed to reserve											7.50%
Kymera
Provisions and other non-current liabilities [Line Items]
Upfront payment		$ 150
Commitments related to milestone payments for projects under collaboration agreements		$ 2,200
Joint ventures
Provisions and other non-current liabilities [Line Items]
Percentage of future development expense funded by other party					5000.00%
Dice Molecules
Provisions and other non-current liabilities [Line Items]
Collaboration period									5 years
Lonza | Joint ventures
Provisions and other non-current liabilities [Line Items]
Investments in joint ventures | €					€ 300
Percentage of future development expense funded by company					50.00%
Amounts payable partners in collaboration agreements | €					€ 600
Share of operating expenses and cost of production to joint partner payable period					15 years
Kymab | Entering into significant commitments or contingent liabilities
Provisions and other non-current liabilities [Line Items]
Upfront payment	$ 1,100
Commitments related to milestone payments for projects under collaboration agreements	$ 350

Off balance sheet commitments_3

Off balance sheet commitments - Summary of Undrawn Credit Facilities (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Line of Credit Facility [Line Items]
General-purpose credit facilities	€ 8,000	€ 8,000	€ 8,000
Less than 1 year
Disclosure Of Line of Credit Facility [Line Items]
General-purpose credit facilities	4,000
From 1 to 3 years
Disclosure Of Line of Credit Facility [Line Items]
General-purpose credit facilities	0
From 3 to 5 years
Disclosure Of Line of Credit Facility [Line Items]
General-purpose credit facilities	4,000
More than 5 years
Disclosure Of Line of Credit Facility [Line Items]
General-purpose credit facilities	€ 0

Off balance sheet commitments_4

Off balance sheet commitments - Summary of Amount of Guarantees Given and Received (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Guarantees given:
Disclosure of Guarantees [Line Items]
Estimated financial effect of contingent liabilities	€ 3,291	€ 3,103	€ 3,010
Guarantees provided to banks in connection with credit facilities
Disclosure of Guarantees [Line Items]
Estimated financial effect of contingent liabilities	695	1,263	1,307
Other guarantees given
Disclosure of Guarantees [Line Items]
Estimated financial effect of contingent liabilities	2,596	1,840	1,703
Guarantees received
Disclosure of Guarantees [Line Items]
Estimated financial effect of contingent liabilities	€ (964)	€ (703)	€ (190)

Legal and arbitral proceedings

Legal and arbitral proceedings - Additional Information (Details) $ in Millions

May 14, 2013EUR (€)

Oct. 31, 2020GBP (£)

Feb. 29, 2020claimant

Oct. 31, 2018USD ($)

Sep. 30, 2017EUR (€)

Jan. 31, 2004EUR (€)plaintiffclaim

Jul. 31, 2017petition

Apr. 30, 2020action

Dec. 31, 2020EUR (€)plaintiffinjury_casecomplaintlawsuitmanufacturersiteactionclaimantclaim

Dec. 31, 2020USD ($)lawsuitsitemanufacturerclaim

Dec. 31, 2020AUD ($)lawsuitsitemanufacturerclaim

Jul. 31, 2020claim

Dec. 31, 2019EUR (€)claim

Aug. 31, 2019claim

Apr. 30, 2019claim

Feb. 28, 2019claim

Dec. 31, 2018EUR (€)

Nov. 30, 2017EUR (€)

Oct. 31, 2017decisionappeal

May 31, 2017patent

Jan. 31, 2017patent

Nov. 24, 2016entity

Jul. 31, 2016entity

Mar. 31, 2016patent

Dec. 31, 2014complaint

Nov. 18, 2014patent

Dec. 31, 1997EUR (€)

Disclosure of Legal and Arbitral Proceedings [Line Items]

Provisions for product liability risks, litigation and other

€ 1,262,000,000

€ 1,334,000,000

€ 1,288,000,000

Environmental risks

€ 713,000,000

737,000,000

€ 680,000,000

Litigation amount payable

€ 315,000,000

Sanofi Pasteur Hepatitis B Vaccine Product Litigation Since 1996 | Action for which we are defendant | Product liabilities

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of civil individual actions | lawsuit

180

180

180

Number of appeals dismissed | appeal

2

Number of decisions made by appeal court | decision

2

Taxotere product litigation in the US | Action for which we are defendant | Product liabilities

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of plaintiffs | plaintiff

10,137

Number of loss consortium plaintiffs | plaintiff

871

Taxotere mississippi attorney general litigation in the US | Action for which we are defendant | Product liabilities

Disclosure of Legal and Arbitral Proceedings [Line Items]

Maximum penalty amount sought by plaintiffs for each violation | $

$ 10,000

Zantac litigation in the US | Action for which we are defendant | Product liabilities

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of plaintiffs | plaintiff

1,607

Number of personal injury cases | injury_case

977

Number of class actions | action

25

Zantac litigation in Canada | Action for which we are defendant | Product liabilities

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of class actions | action

2

5

Number of claims on which the class action is based | claimant

21

Depakine product litigation In France | Action for which we are defendant | Product liabilities

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of civil individual actions | claim

75

75

75

63

Number of plaintiffs | claimant

126

Number of lawsuits ruled on merits | lawsuit

23

23

23

Depakine product litigation In France | Action for which we are defendant | Plaintiff

Disclosure of Legal and Arbitral Proceedings [Line Items]

Litigation amount payable

€ 2,000,000

Depakine product litigation In France | Action for which we are defendant | Caisse Primaire D Assurance Maladie

Disclosure of Legal and Arbitral Proceedings [Line Items]

Litigation amount payable

€ 1,000,000

Ramipril Canada Patent Litigation | Action for which we are a plaintiff | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of manufacturers with marketing authorization for generic version of drug | manufacturer

8

8

8

Praluent (Alirocumab)-related amgen patent litigation in the US | Action for which we are defendant | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of patent actions initially filed | complaint

4

Number of patents allegedly infringed | patent

7

Number of patents found infringed | patent

2

Number of claims upheld | claim

3

Number of claims asserted | claim

5

Number of claims invalid | claim

5

3

2

Praluent (Alirocumab) related Amgen patent litigation in Europe | Action for which we are defendant | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of patent actions initially filed | lawsuit

6

6

6

Praluent (Alirocumab)-related Amgen patent litigation in United Kingdom | Action for which we are defendant | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of entities included in litigation | entity

5

Gains on litigation settlements | £

£ 50,000

Praluent (Alirocumab)-related Amgen patent litigation in Germany | Action for which we are defendant | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of entities included in litigation | entity

3

Praluent (Alirocumab)-related EPO patent oppositions | Action for which we are a plaintiff | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Injunctive relief, number of patents | patent

2

Number of entities included in litigation | entity

3

Praluent related Amgen Opposition and patent litigation in Japan | Action for which we are defendant | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of patent actions initially filed | patent

2

Dupixent related Amgen Iprs and patent litigation in the US | Action for which we are a plaintiff | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of IPR petitions | petition

3

Number of claims appealed | claim

17

Jevtana related patent litigation in the US | Action for which we are a plaintiff | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of patents allegedly infringed | claim

12

Plavix litigation (Commonwealth) in Australia | Action for which we are defendant | Patents

Disclosure of Legal and Arbitral Proceedings [Line Items]

Security bond posted increased from | $

$ 40

Security bond posted increased to | $

204

Apotex sought damages range from | $

20

Apotex sought damages range to | $

236

Payment of damages sought by Australian Department of Health related to the Apotex preliminary injunction, up to

€ 283,000,000

$ 449

Plavix related litigation in France | Action for which we are defendant

Disclosure of Legal and Arbitral Proceedings [Line Items]

Penalty amount paid to the French Antitrust Authority

€ 40,600,000

Payment of damages claimed by the French CNAM (French Social Security)

€ 115,800,000

Aventis Behring retained liabilities | Contingencies arising from certain Business Divestitures

Disclosure of Legal and Arbitral Proceedings [Line Items]

Threshold amount relating to losses triggering indemnification | $

$ 10,000,000

Indemnification aggregate cap | $

$ 300,000,000

Indemnification related to environmental indemnifiable losses limited to

90.00%

90.00%

90.00%

Indemnification aggregate cap related to product liability claims | $

$ 500,000,000

Aventis crop science retained liabilities | Contingencies arising from certain Business Divestitures

Disclosure of Legal and Arbitral Proceedings [Line Items]

Aggregate participation percentage of legacy companies in ACS

76.00%

Global indemnification cap and indemnification cap related to environmental liabilities

€ 836,000,000

Indemnification cap related to product liability cases

418,000,000

Aventis animal nutrition retained liabilities | Contingencies arising from certain Business Divestitures

Disclosure of Legal and Arbitral Proceedings [Line Items]

Global indemnification cap

223,000,000

Celanese A G retained liabilities | Contingencies arising from certain Business Divestitures

Disclosure of Legal and Arbitral Proceedings [Line Items]

Environmental damages amount up to which CCC is liable to indemnification

250,000,000

Environmental damages amount up to which Hoechst is liable to indemnification and from which liabilities are shared between Hoechst and CCC

€ 750,000,000

Rhodia shareholder litigation | Action for which we are defendant

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of criminal complaints | complaint

3

Rhodia shareholder litigation | Action for which we are defendant | Contingencies arising from certain Business Divestitures

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of plaintiffs | plaintiff

2

Number of claims before a commercial court | claim

2

Amount of damages sought by plaintiffs to be awarded to Rhodia

€ 925,000,000

Amount of damages for alleged individual losses sought by plaintiff 1

4,300,000

Amount of damages for alleged individual losses sought by plaintiff 2

€ 125,400,000

Clariant retained liabilities - specially chemicals business | Contingencies arising from certain Business Divestitures

Disclosure of Legal and Arbitral Proceedings [Line Items]

Number of specific waste deposit sites | site

4

4

4

Threshold amount, relating to environmental costs attributable to four defined waste deposit sites in Germany, triggering indemnification to Clariant

€ 20,500,000

Costs related to specific waste deposit site, percentage

75.00%

Infraserv Hoechst retained liabilities | Contingencies arising from certain Business Divestitures

Disclosure of Legal and Arbitral Proceedings [Line Items]

Fund reserves transferred

€ 57,000,000

Maximum amount to be reimbursed for current and future environmental expense

€ 143,000,000

Provisions for discounts, reb_3

Provisions for discounts, rebates and sales returns - Summary of Movement in Provisions for Discounts, Rebates and Sales Returns (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	€ 5,218	€ 4,815	€ 4,746
Changes in scope of consolidation			(82)
Provision related to current period sales	20,314	19,292	16,745
Net change in provision related to prior period sales	(201)	(47)	(50)
Payments made	(19,174)	(18,950)	(16,676)
Currency translation differences	(118)	108	132
Provisions for discounts, rebates and sales returns, Ending balance	6,039	5,218	4,815
Government And State Programs
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	2,178	2,148	2,086
Changes in scope of consolidation			37
Provision related to current period sales	5,970	5,542	4,624
Net change in provision related to prior period sales	(54)	(27)	(2)
Payments made	(5,552)	(5,529)	(4,673)
Currency translation differences	(35)	44	76
Provisions for discounts, rebates and sales returns, Ending balance	2,507	2,178	2,148
Managed care and GPO Programs
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	726	674	663
Changes in scope of consolidation			2
Provision related to current period sales	2,752	2,563	2,038
Net change in provision related to prior period sales	0	0	(4)
Payments made	(2,556)	(2,528)	(2,055)
Currency translation differences	(14)	17	30
Provisions for discounts, rebates and sales returns, Ending balance	908	726	674
Chargeback incentives
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	312	294	377
Changes in scope of consolidation			0
Provision related to current period sales	4,633	4,649	3,620
Net change in provision related to prior period sales	0	(1)	(1)
Payments made	(4,604)	(4,637)	(3,714)
Currency translation differences	(8)	7	12
Provisions for discounts, rebates and sales returns, Ending balance	333	312	294
Rebates and discounts
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	1,330	1,140	1,067
Changes in scope of consolidation			(123)
Provision related to current period sales	6,221	5,888	5,942
Net change in provision related to prior period sales	(113)	(6)	(11)
Payments made	(5,838)	(5,719)	(5,732)
Currency translation differences	(43)	27	(3)
Provisions for discounts, rebates and sales returns, Ending balance	1,557	1,330	1,140
Sales returns
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	621	546	547
Changes in scope of consolidation			0
Provision related to current period sales	628	554	465
Net change in provision related to prior period sales	(34)	(27)	(35)
Payments made	(512)	(465)	(448)
Currency translation differences	(15)	13	17
Provisions for discounts, rebates and sales returns, Ending balance	688	621	546
Other deductions
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	51	13	6
Changes in scope of consolidation			2
Provision related to current period sales	110	96	56
Net change in provision related to prior period sales	0	14	3
Payments made	(112)	(72)	(54)
Currency translation differences	(3)	0	0
Provisions for discounts, rebates and sales returns, Ending balance	46	51	13
USA
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	3,585	3,509
Provisions for discounts, rebates and sales returns, Ending balance	3,982	3,585	3,509
USA | Managed care
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	649	604
Provisions for discounts, rebates and sales returns, Ending balance	692	649	604
Medicaid | Government And State Programs
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance		1,033
Provisions for discounts, rebates and sales returns, Ending balance			1,033
Medicaid | Managed care and GPO Programs
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	1,017
Provisions for discounts, rebates and sales returns, Ending balance	1,015	1,017
Medicare | Managed care and GPO Programs
Disclosure of other provisions [line items]
Provisions for discounts, rebates and sales returns, Beginning balance	810	829
Provisions for discounts, rebates and sales returns, Ending balance	€ 726	€ 810	€ 829

Personnel costs - Summary of Pe

Personnel costs - Summary of Personal Costs (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Benefits [Abstract]
Salaries	€ 6,508	€ 6,590	€ 6,547
Social security charges (including defined-contribution pension plans)	1,874	1,949	1,954
Stock options and other share-based payment expense	274	252	282
Defined-benefit plans	159	119	261
Other employee benefits	261	229	225
Total	€ 9,076	€ 9,139	€ 9,269

Personnel costs - Additional In

Personnel costs - Additional Information (Details) - employee	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Benefits [Abstract]
Number of employees	99,412	100,409	104,226

Other operating income - Additi

Other operating income - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Other Operating Income [Line Items]
Other operating income	€ 696	€ 825	€ 484
Other operating income (expense)
Disclosure Of Other Operating Income [Line Items]
Gains on divestment of some mature products	307	296	326
Gain on data transfer agreement			112
Regeneron | Other operating income (expense)
Disclosure Of Other Operating Income [Line Items]
Other operating income	164	82	4
Other related parties | Other operating income (expense)
Disclosure Of Other Operating Income [Line Items]
Other operating income	€ 199	€ 103	€ 32

Other operating expenses - Addi

Other operating expenses - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Other Operating Income Expenses [Line Items]
Other operating expense	€ 1,415	€ 1,207	€ 548
Other operating expense, share of profits due to alliance partners other than BMS	16	28	50
Acquisition-related costs	29		56
Regeneron Pharmaceuticals, INC
Disclosure Of Other Operating Income Expenses [Line Items]
Other operating expense	€ 1,090	€ 715	€ 225

Other operating expenses - Othe

Other operating expenses - Other Income and Expense (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Other Operating Income Expenses [Line Items]
Miscellaneous other operating expense	€ (1,415)	€ (1,207)	€ (548)
Other operating income	696	825	484
Other operating income/(expenses), net related to the Regeneron Alliance	(926)	(633)	(221)
Regeneron | Other operating income (expense)
Disclosure Of Other Operating Income Expenses [Line Items]
Other operating income	164	82	4
Antibodies Alliance
Disclosure Of Other Operating Income Expenses [Line Items]
Miscellaneous other operating expense	(1,001)	(681)	(211)
Antibodies Alliance | Share of profit or loss from commercialization of monoclonal antibodies
Disclosure Of Other Operating Income Expenses [Line Items]
Miscellaneous other operating expense	(727)	(253)	(177)
Antibodies Alliance | Share of profit or loss from commercialization of Zaltrap
Disclosure Of Other Operating Income Expenses [Line Items]
Other operating income	75	21	0
Antibodies Alliance | Commercialization related expenses
Disclosure Of Other Operating Income Expenses [Line Items]
Miscellaneous other operating expense	(349)	(449)	(388)
Immuno-oncology Alliance
Disclosure Of Other Operating Income Expenses [Line Items]
Other operating income	89	62	4
Others
Disclosure Of Other Operating Income Expenses [Line Items]
Miscellaneous other operating expense	€ (14)	€ (14)	€ (14)

Restructuring costs and simil_3

Restructuring costs and similar items - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of restructuring costs and similar items [line items]
Expense of restructuring activities	€ 1,064	€ 1,062	€ 1,480
Termination benefit payments	690	791
Charges, gains or losses on assets(a)	149	106	162
Sanofi transformation programs	€ 173	€ 109	145
Losses on property plant and equipment due to site closures or divestments			162
Europe
Disclosure of restructuring costs and similar items [line items]
Termination benefit payments			517
Research and development agreement with Regeneron
Disclosure of restructuring costs and similar items [line items]
Provision for penalities from restructuring			283
Evotec | Restructuring costs and similar items
Disclosure of restructuring costs and similar items [line items]
Transfer cost of infectious diseases			252
Upfront payments			€ 60

Restructuring costs and simil_4

Restructuring costs and similar items - Summary of Restructuring Costs and Similar Items (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Analysis of income and expense [abstract]
Employee-related expenses	€ 690	€ 791	€ 517
Charges, gains or losses on assets(a)	149	106	162
Compensation for early termination of contracts (other than contracts of employment)	40	49	352
Decontamination costs	(2)	27	5
Other restructuring costs	187	89	444
Total	€ 1,064	€ 1,062	€ 1,480

Other gains and losses, and l_2

Other gains and losses, and litigation - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Analysis of income and expense [abstract]
Other gains and (losses) and litigation	€ 136	€ 327	€ 502

Financial expenses and income -

Financial expenses and income - Summary of Analysis of Financial Income and Expenses (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about finance income expense [Line Items]
Cost of debt	€ (328)	€ (318)	€ (396)
Interest income	103	146	123
Cost of net debt	(225)	(172)	(273)
Non-operating foreign exchange gains/(losses)	(6)	1	6
Unwinding of discounting of provisions	(11)	(25)	(24)
Net interest cost related to employee benefits	(59)	(87)	(75)
Gains/(losses) on disposals of financial assets	6	0	63
Net interest expense on lease liabilities	(38)	(39)	0
Other	(4)	19	32
Net financial income/(expenses)	(337)	(303)	(271)
comprising: Financial expenses	(390)	(444)	(435)
comprising: financial income	53	141	164
Interest rate and currency derivatives used to hedge debt
Disclosure of detailed information about finance income expense [Line Items]
Gain on derivatives used to manage debt	93	187	75
Gain on derivatives used to manage cash and cash equivalents	€ 66	€ 55	€ 51

Income tax expense - Summary of

Income tax expense - Summary of Allocation of Income Tax Expense Between Current and Deferred Taxes (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Current taxes	€ (1,912)	€ (1,892)	€ (1,212)
Deferred taxes	99	1,753	731
Total	(1,813)	(139)	(481)
Income before tax and investments accounted for using the equity method	€ 13,804	€ 2,822	€ 4,405

Income tax expense - Summary _2

Income tax expense - Summary of Difference Between Effective Tax Rate and Standard Corporate Income Tax Rate (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Difference of Effective Tax Rate and Standard Corporate Income Tax Rate [Line items]
Standard tax rate applicable in France	32.00%	34.40%	34.40%
Difference between the standar0d French tax rate and the rates applicable to the Sanofi	(18.20%)	(22.90%)	(17.40%)
Revisions to tax exposures and settlements of tax disputes	0.50%	4.80%	(1.40%)
Impact of US tax reform	0.00%	0.00%	(4.30%)
Impact of past acquisitions and divestitures	0.00%	(6.20%)	0.00%
Fair value remeasurement of contingent considerations	0.00%	(2.60%)	0.20%
Other items	(1.20%)	(2.60%)	(0.60%)
Effective tax rate	13.10%	4.90%	10.90%
United States
Disclosure of Difference of Effective Tax Rate and Standard Corporate Income Tax Rate [Line items]
Tax reform			€ 188

Share of profit_loss of investm

Share of profit/loss of investments accounted for using the equity method - Summary of Analysis of Share of Profit/Loss from Investments Accounted for Using Equity Method (Details) € in Millions, $ in Millions	May 29, 2020shares	Feb. 28, 2020USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Disclosure of associates [line items]
Share of profit (loss) of associates and joint ventures accounted for using equity method			€ 359	€ 255	€ 499
Regeneron
Disclosure of associates [line items]
Share of profit (loss) of associates and joint ventures accounted for using equity method			343	245	484
Sale of stock, number of shares issued in transaction (in shares) | shares	22,800,000
BMS co- promotion entities
Disclosure of associates [line items]
Share of profit (loss) of associates and joint ventures accounted for using equity method			1	5	12
Other investments accounted for using the equity method
Disclosure of associates [line items]
Share of profit (loss) of associates and joint ventures accounted for using equity method			€ 15	€ 5	€ 3
Entities and companies managed by Bristol Mayers Squibb
Disclosure of associates [line items]
Equity interest		50.10%
Purchase of interests in investments accounted for using equity method | $		$ 12

Share of profit_loss of inves_2

Share of profit/loss of investments accounted for using the equity method - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of share of profit loss of associates and joint ventures [line items]
Share of profit/loss from investments accounted for using equity method	€ 359	€ 255	€ 499
Regeneron
Disclosure of share of profit loss of associates and joint ventures [line items]
Share of profit/loss from investments accounted for using equity method	€ 343	€ 245	€ 484

Net income attributable to no_3

Net income attributable to non-controlling interests - Summary of Trends in Net Income Attributable to Non-Controlling Interests (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of net income attributable to non-controlling interests [line items]
Net income attributable to non-controlling interests	€ 36	€ 31	€ 104
BMS
Disclosure of net income attributable to non-controlling interests [line items]
Net income attributable to non-controlling interests	0	0	83
Other investments
Disclosure of net income attributable to non-controlling interests [line items]
Net income attributable to non-controlling interests	€ 36	€ 31	€ 21

Related party transactions - Ad

Related party transactions - Additional Information (Details) - executives	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party [Abstract]
Average number of members of executive committee	11	15	15

Related party transactions - Sc

Related party transactions - Schedule of Compensation Paid to Key Management Personnel (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of compensation paid to key management personnel [abstract]
Short-term benefits	€ 36	€ 31	€ 38
Post-employment benefits	3	(8)	9
Share-based payment	18	30	33
Total recognized in profit or loss	€ 57	€ 53	€ 80

Related party transactions - Su

Related party transactions - Summary of aggregate amounts Payable to Key Management Personnel (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party [Abstract]
Aggregate top-up pension obligation	€ 28	€ 48	€ 59
Aggregate termination benefits and lump-sum retirement benefits	€ 6	€ 5	€ 10

Disclosures about major custo_2

Disclosures about major customers and credit risk - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of information about major customers and credit risk [line items]
Percentage of entity's revenue			4.00%
Largest customers
Disclosure of information about major customers and credit risk [line items]
Percentage of entity's revenue	21.00%
Customer one
Disclosure of information about major customers and credit risk [line items]
Percentage of entity's revenue	10.00%	8.00%	9.00%
Customer two
Disclosure of information about major customers and credit risk [line items]
Percentage of entity's revenue	6.00%	5.00%	6.00%
Customer three
Disclosure of information about major customers and credit risk [line items]
Percentage of entity's revenue	5.00%	3.00%

Segment information - Additiona

Segment information - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020segmentshares	May 29, 2020shares
Disclosure of operating segments [line items]
Number of operating segments | segment	3
Regeneron
Disclosure of operating segments [line items]
Non-current financial assets, number of shares (in shares) | shares	279,766	400,000

Segment information - Summary o

Segment information - Summary of Net Sales by Segment and Geographical Area (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of geographical areas [line items]
Net sales	€ 36,041	€ 36,126	€ 34,463
Pharmaceuticals
Disclosure of geographical areas [line items]
Net sales	25,674	25,700	24,685
Pharmaceuticals | General Medicines
Disclosure of geographical areas [line items]
Net sales	14,720	16,537	16,416
Pharmaceuticals | Lantus
Disclosure of geographical areas [line items]
Net sales	2,661	3,012	3,565
Pharmaceuticals | Toujeo
Disclosure of geographical areas [line items]
Net sales	933	883	840
Pharmaceuticals | Praluent
Disclosure of geographical areas [line items]
Net sales	261	258	261
Pharmaceuticals | Multaq
Disclosure of geographical areas [line items]
Net sales	312	347	350
Pharmaceuticals | Lovenox
Disclosure of geographical areas [line items]
Net sales	1,351	1,359	1,465
Pharmaceuticals | Plavix
Disclosure of geographical areas [line items]
Net sales	916	1,334	1,440
Pharmaceuticals | Generics
Disclosure of geographical areas [line items]
Net sales	932	1,074	1,490
Pharmaceuticals | Specialty Care
Disclosure of geographical areas [line items]
Net sales	10,954	9,163	8,269
Pharmaceuticals | Aubagio
Disclosure of geographical areas [line items]
Net sales	2,045	1,879	1,647
Pharmaceuticals | Cerezyme
Disclosure of geographical areas [line items]
Net sales	690	708	711
Pharmaceuticals | Myozyme/Lumizyme
Disclosure of geographical areas [line items]
Net sales	948	918	840
Pharmaceuticals | Fabrazyme
Disclosure of geographical areas [line items]
Net sales	817	813	755
Pharmaceuticals | Eloctate
Disclosure of geographical areas [line items]
Net sales	638	684	608
Pharmaceuticals | Jevtana
Disclosure of geographical areas [line items]
Net sales	536	484	422
Pharmaceuticals | Dupixent
Disclosure of geographical areas [line items]
Net sales	3,534	2,074	788
Consumer Healthcare
Disclosure of geographical areas [line items]
Net sales	4,394	4,695	4,660
Consumer Healthcare | Allergy, Cough & Cold
Disclosure of geographical areas [line items]
Net sales	1,096	1,189	1,124
Consumer Healthcare | Pain
Disclosure of geographical areas [line items]
Net sales	1,225	1,280	1,254
Consumer Healthcare | Digestive
Disclosure of geographical areas [line items]
Net sales	858	985	986
Consumer Healthcare | Nutritionals
Disclosure of geographical areas [line items]
Net sales	611	621	675
Vaccines
Disclosure of geographical areas [line items]
Net sales	5,973	5,731	5,118
Vaccines | Polio/Pertussis/ Hib Vaccines
Disclosure of geographical areas [line items]
Net sales	2,106	1,946	1,749
Vaccines | Influenza Vaccines
Disclosure of geographical areas [line items]
Net sales	2,472	1,891	1,708
Europe
Disclosure of geographical areas [line items]
Net sales	9,151	9,082	9,434
Europe | Pharmaceuticals
Disclosure of geographical areas [line items]
Net sales	6,819	6,797	7,303
Europe | Pharmaceuticals | General Medicines
Disclosure of geographical areas [line items]
Net sales	4,505	4,809	5,299
Europe | Pharmaceuticals | Lantus
Disclosure of geographical areas [line items]
Net sales	537	599	684
Europe | Pharmaceuticals | Toujeo
Disclosure of geographical areas [line items]
Net sales	374	343	290
Europe | Pharmaceuticals | Praluent
Disclosure of geographical areas [line items]
Net sales	121	112	86
Europe | Pharmaceuticals | Multaq
Disclosure of geographical areas [line items]
Net sales	24	41	43
Europe | Pharmaceuticals | Lovenox
Disclosure of geographical areas [line items]
Net sales	656	730	870
Europe | Pharmaceuticals | Plavix
Disclosure of geographical areas [line items]
Net sales	129	142	147
Europe | Pharmaceuticals | Generics
Disclosure of geographical areas [line items]
Net sales	100	139	568
Europe | Pharmaceuticals | Specialty Care
Disclosure of geographical areas [line items]
Net sales	2,314	1,988	2,004
Europe | Pharmaceuticals | Aubagio
Disclosure of geographical areas [line items]
Net sales	473	414	385
Europe | Pharmaceuticals | Cerezyme
Disclosure of geographical areas [line items]
Net sales	249	259	270
Europe | Pharmaceuticals | Myozyme/Lumizyme
Disclosure of geographical areas [line items]
Net sales	389	388	374
Europe | Pharmaceuticals | Fabrazyme
Disclosure of geographical areas [line items]
Net sales	200	185	175
Europe | Pharmaceuticals | Eloctate
Disclosure of geographical areas [line items]
Net sales	0	0	0
Europe | Pharmaceuticals | Jevtana
Disclosure of geographical areas [line items]
Net sales	187	170	158
Europe | Pharmaceuticals | Dupixent
Disclosure of geographical areas [line items]
Net sales	386	204	75
Europe | Consumer Healthcare
Disclosure of geographical areas [line items]
Net sales	1,359	1,434	1,403
Europe | Consumer Healthcare | Allergy, Cough & Cold
Disclosure of geographical areas [line items]
Net sales	305	364	347
Europe | Consumer Healthcare | Pain
Disclosure of geographical areas [line items]
Net sales	539	543	521
Europe | Consumer Healthcare | Digestive
Disclosure of geographical areas [line items]
Net sales	319	326	314
Europe | Consumer Healthcare | Nutritionals
Disclosure of geographical areas [line items]
Net sales	127	130	125
Europe | Vaccines
Disclosure of geographical areas [line items]
Net sales	973	851	728
Europe | Vaccines | Polio/Pertussis/ Hib Vaccines
Disclosure of geographical areas [line items]
Net sales	331	315	296
Europe | Vaccines | Influenza Vaccines
Disclosure of geographical areas [line items]
Net sales	441	230	177
USA
Disclosure of geographical areas [line items]
Net sales	13,465	12,756	11,540
USA | Pharmaceuticals
Disclosure of geographical areas [line items]
Net sales	9,635	8,918	7,897
USA | Pharmaceuticals | General Medicines
Disclosure of geographical areas [line items]
Net sales	2,869	3,386	3,510
USA | Pharmaceuticals | Lantus
Disclosure of geographical areas [line items]
Net sales	929	1,149	1,614
USA | Pharmaceuticals | Toujeo
Disclosure of geographical areas [line items]
Net sales	267	289	344
USA | Pharmaceuticals | Praluent
Disclosure of geographical areas [line items]
Net sales	106	112	154
USA | Pharmaceuticals | Multaq
Disclosure of geographical areas [line items]
Net sales	274	295	296
USA | Pharmaceuticals | Lovenox
Disclosure of geographical areas [line items]
Net sales	30	33	38
USA | Pharmaceuticals | Plavix
Disclosure of geographical areas [line items]
Net sales	10	0	0
USA | Pharmaceuticals | Generics
Disclosure of geographical areas [line items]
Net sales	161	152	124
USA | Pharmaceuticals | Specialty Care
Disclosure of geographical areas [line items]
Net sales	6,766	5,532	4,387
USA | Pharmaceuticals | Aubagio
Disclosure of geographical areas [line items]
Net sales	1,448	1,351	1,157
USA | Pharmaceuticals | Cerezyme
Disclosure of geographical areas [line items]
Net sales	177	184	174
USA | Pharmaceuticals | Myozyme/Lumizyme
Disclosure of geographical areas [line items]
Net sales	359	331	284
USA | Pharmaceuticals | Fabrazyme
Disclosure of geographical areas [line items]
Net sales	406	410	383
USA | Pharmaceuticals | Eloctate
Disclosure of geographical areas [line items]
Net sales	445	517	500
USA | Pharmaceuticals | Jevtana
Disclosure of geographical areas [line items]
Net sales	246	212	179
USA | Pharmaceuticals | Dupixent
Disclosure of geographical areas [line items]
Net sales	2,808	1,669	660
USA | Consumer Healthcare
Disclosure of geographical areas [line items]
Net sales	1,071	1,105	1,066
USA | Consumer Healthcare | Allergy, Cough & Cold
Disclosure of geographical areas [line items]
Net sales	361	323	303
USA | Consumer Healthcare | Pain
Disclosure of geographical areas [line items]
Net sales	181	185	165
USA | Consumer Healthcare | Digestive
Disclosure of geographical areas [line items]
Net sales	86	157	195
USA | Consumer Healthcare | Nutritionals
Disclosure of geographical areas [line items]
Net sales	43	38	37
USA | Vaccines
Disclosure of geographical areas [line items]
Net sales	2,759	2,733	2,577
USA | Vaccines | Polio/Pertussis/ Hib Vaccines
Disclosure of geographical areas [line items]
Net sales	412	380	397
USA | Vaccines | Influenza Vaccines
Disclosure of geographical areas [line items]
Net sales	1,575	1,289	1,233
Other countries
Disclosure of geographical areas [line items]
Net sales	13,425	14,288	13,489
Other countries | Pharmaceuticals
Disclosure of geographical areas [line items]
Net sales	9,220	9,985	9,485
Other countries | Pharmaceuticals | General Medicines
Disclosure of geographical areas [line items]
Net sales	7,346	8,342	7,607
Other countries | Pharmaceuticals | Lantus
Disclosure of geographical areas [line items]
Net sales	1,195	1,264	1,267
Other countries | Pharmaceuticals | Toujeo
Disclosure of geographical areas [line items]
Net sales	292	251	206
Other countries | Pharmaceuticals | Praluent
Disclosure of geographical areas [line items]
Net sales	34	34	21
Other countries | Pharmaceuticals | Multaq
Disclosure of geographical areas [line items]
Net sales	14	11	11
Other countries | Pharmaceuticals | Lovenox
Disclosure of geographical areas [line items]
Net sales	665	596	557
Other countries | Pharmaceuticals | Plavix
Disclosure of geographical areas [line items]
Net sales	777	1,192	1,293
Other countries | Pharmaceuticals | Generics
Disclosure of geographical areas [line items]
Net sales	671	783	798
Other countries | Pharmaceuticals | Specialty Care
Disclosure of geographical areas [line items]
Net sales	1,874	1,643	1,878
Other countries | Pharmaceuticals | Aubagio
Disclosure of geographical areas [line items]
Net sales	124	114	105
Other countries | Pharmaceuticals | Cerezyme
Disclosure of geographical areas [line items]
Net sales	264	265	267
Other countries | Pharmaceuticals | Myozyme/Lumizyme
Disclosure of geographical areas [line items]
Net sales	200	199	182
Other countries | Pharmaceuticals | Fabrazyme
Disclosure of geographical areas [line items]
Net sales	211	218	197
Other countries | Pharmaceuticals | Eloctate
Disclosure of geographical areas [line items]
Net sales	193	167	108
Other countries | Pharmaceuticals | Jevtana
Disclosure of geographical areas [line items]
Net sales	103	102	85
Other countries | Pharmaceuticals | Dupixent
Disclosure of geographical areas [line items]
Net sales	340	201	53
Other countries | Consumer Healthcare
Disclosure of geographical areas [line items]
Net sales	1,964	2,156	2,191
Other countries | Consumer Healthcare | Allergy, Cough & Cold
Disclosure of geographical areas [line items]
Net sales	430	502	474
Other countries | Consumer Healthcare | Pain
Disclosure of geographical areas [line items]
Net sales	505	552	568
Other countries | Consumer Healthcare | Digestive
Disclosure of geographical areas [line items]
Net sales	453	502	477
Other countries | Consumer Healthcare | Nutritionals
Disclosure of geographical areas [line items]
Net sales	441	453	513
Other countries | Vaccines
Disclosure of geographical areas [line items]
Net sales	2,241	2,147	1,813
Other countries | Vaccines | Polio/Pertussis/ Hib Vaccines
Disclosure of geographical areas [line items]
Net sales	1,363	1,251	1,056
Other countries | Vaccines | Influenza Vaccines
Disclosure of geographical areas [line items]
Net sales	€ 456	€ 372	€ 298

Segment information - Schedule

Segment information - Schedule of Segment Results (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [line items]
Net sales	€ 36,041	€ 36,126	€ 34,463
Other revenues	1,328	1,505	1,214
Cost of sales	(12,157)	(11,976)	(11,435)
Research and development expenses	(5,529)	(6,018)	(5,894)
Selling and general expenses	(9,390)	(9,883)	(9,859)
Share of profit (loss) of associates and joint ventures accounted for using equity method	359	255	499
Net income attributable to non-controlling interests	36	31	104
Reclassification from Other to operating segments		291
Pharmaceuticals
Disclosure of operating segments [line items]
Net sales	25,674	25,700	24,685
Other revenues	128	173	252
Cost of sales	(7,025)	(6,750)	(6,738)
Research and development expenses	(4,331)	(4,850)	(4,572)
Selling and general expenses	(5,097)	(5,442)	(5,431)
Other operating income and expenses	(488)	(625)	(37)
Share of profit (loss) of associates and joint ventures accounted for using equity method	5	5	17
Net income attributable to non-controlling interests	(33)	(29)	(96)
Business operating income	8,833	8,182	8,080
Consumer Healthcare
Disclosure of operating segments [line items]
Net sales	4,394	4,695	4,660
Other revenues	59	57	0
Cost of sales	(1,506)	(1,599)	(1,539)
Research and development expenses	(136)	(149)	(143)
Selling and general expenses	(1,450)	(1,529)	(1,534)
Other operating income and expenses	54	193	101
Share of profit (loss) of associates and joint ventures accounted for using equity method	9	(5)	1
Net income attributable to non-controlling interests	(5)	(6)	(10)
Business operating income	1,419	1,657	1,536
Vaccines
Disclosure of operating segments [line items]
Net sales	5,973	5,731	5,118
Other revenues	1,141	1,275	962
Cost of sales	(3,328)	(3,372)	(2,854)
Research and development expenses	(692)	(639)	(555)
Selling and general expenses	(822)	(823)	(710)
Other operating income and expenses	2	0	(4)
Share of profit (loss) of associates and joint ventures accounted for using equity method	2	9	(3)
Net income attributable to non-controlling interests	0	0	0
Business operating income	2,276	2,181	1,954
Other
Disclosure of operating segments [line items]
Net sales	0	0	0
Other revenues	0	0	0
Cost of sales	(245)	(252)	(190)
Research and development expenses	(370)	(380)	(624)
Selling and general expenses	(2,021)	(2,089)	(2,156)
Other operating income and expenses	(130)	50	(124)
Share of profit (loss) of associates and joint ventures accounted for using equity method	0	0	0
Net income attributable to non-controlling interests	0	0	0
Business operating income	(2,766)	(2,671)	(3,094)
Total Sanofi
Disclosure of operating segments [line items]
Net sales	36,041	36,126	34,463
Other revenues	1,328	1,505	1,214
Cost of sales	(12,104)	(11,973)	(11,321)
Research and development expenses	(5,529)	(6,018)	(5,894)
Selling and general expenses	(9,390)	(9,883)	(9,831)
Other operating income and expenses	(562)	(382)	(64)
Share of profit (loss) of associates and joint ventures accounted for using equity method	16	9	15
Net income attributable to non-controlling interests	(38)	(35)	(106)
Business operating income	€ 9,762	€ 9,349	€ 8,476

Segment information - Schedul_2

Segment information - Schedule of Reconciliation Between Business Operating Income for the Segments and Income Before Tax and Investments Accounted for Using the Equity Method (Details) - EUR (€) € in Millions	May 29, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [line items]
Share of profit (loss) of associates and joint ventures accounted for using equity method			€ 359	€ 255	€ 499
Net income attributable to non-controlling interests			36	31	104
Fair value remeasurement of contingent consideration			124	238	117
Restructuring costs and similar items			(1,064)	(1,062)	(1,480)
Other gains and losses, and litigation			136	327	502
Operating income			14,141	3,125	4,676
Financial expenses			(390)	(444)	(435)
Financial income			53	141	164
Income before tax and investments accounted for using the equity method			13,804	2,822	4,405
Share of profit/(loss) from investments accounted for using the equity method			359	255	499
Regeneron
Disclosure of operating segments [line items]
Share of profit (loss) of associates and joint ventures accounted for using equity method			€ 343	€ 245	484
Non-current financial assets, number of shares (in shares)	400,000	279,766	279,766
Sale of stock, number of shares issued in transaction (in shares)	22,800,000
Regeneron | Public Offering
Disclosure of operating segments [line items]
Sale of stock, number of shares issued in transaction (in shares)	13,000,000	120,234		530,172
Regeneron | Repurchase From The Counterpart | Regeneron Pharmaceuticals, INC
Disclosure of operating segments [line items]
Shares agreement, sale of stock, number of shares issued in transaction (in shares)	9,800,000
Operating segments
Disclosure of operating segments [line items]
Business Operating Income			€ 9,762	€ 9,349	8,476
Operating segments | Regeneron
Disclosure of operating segments [line items]
Share of profit/(loss) from investments accounted for using the equity method				411	408
Material reconciling items
Disclosure of operating segments [line items]
Share of profit (loss) of associates and joint ventures accounted for using equity method			(16)	(9)	(15)
Net income attributable to non-controlling interests			38	35	106
Amortization and impairment of intangible assets			(2,011)	(5,750)	(2,888)
Fair value remeasurement of contingent consideration			124	238	117
Expenses arising from the impact of acquisitions on inventories			(53)	(3)	(114)
Restructuring costs and similar items			(1,064)	(1,062)	(1,480)
Other expenses related to business combinations			0	0	(28)
Other gains and losses, and litigation			136	327	502
Gain on divestment of Regeneron shares			€ 7,225	€ 0	0
Discontinued operations | European Generics Business
Disclosure of operating segments [line items]
Gain loss on divestitures assets					€ 510

Segment information - Schedul_3

Segment information - Schedule of Acquisition of Intangible Assets, Property, Plant and Equipment and Investments Accounted for Using the Equity Method by Segment (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Regeneron Pharmaceuticals, INC
Disclosure of operating segments [line items]
Carrying amount		€ 3,342	€ 3,055
Pharmaceuticals
Disclosure of operating segments [line items]
Investments accounted for using the equity method	€ 154	205	297
Acquisitions of property, plant and equipment	755	773	1,046
Acquisitions of other intangible assets	532	321	434
Consumer Healthcare
Disclosure of operating segments [line items]
Investments accounted for using the equity method	0	4	20
Acquisitions of property, plant and equipment	95	88	5
Acquisitions of other intangible assets	6	51	7
Vaccines
Disclosure of operating segments [line items]
Investments accounted for using the equity method	47	40	30
Acquisitions of property, plant and equipment	404	462	364
Acquisitions of other intangible assets	322	121	121
Reportable segments
Disclosure of operating segments [line items]
Investments accounted for using the equity method	201	249	347
Acquisitions of property, plant and equipment	1,254	1,323	1,415
Acquisitions of other intangible assets	€ 860	€ 493	€ 562

Segment information - Summary_2

Segment information - Summary of Geographical Information on Net Sales and Non-Current Assets (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of geographical areas [line items]
Net sales	€ 36,041	€ 36,126	€ 34,463
Property, plant and equipment	9,365	9,717	9,651
Goodwill	44,364	44,519	44,235
Other intangible assets	18,421	16,572	21,889
Reportable geographical zones
Disclosure of geographical areas [line items]
Net sales	36,041	36,126	34,463
Property, plant and equipment	9,365	9,717	9,651
Goodwill	44,364	44,519	44,235
Other intangible assets	18,421	16,572	21,889
Europe
Disclosure of geographical areas [line items]
Net sales	9,151	9,082	9,434
Property, plant and equipment	5,895	5,827	5,871
Goodwill	0	0	0
Other intangible assets	6,278	6,941	8,058
France
Disclosure of geographical areas [line items]
Net sales	2,223	2,261	2,319
Property, plant and equipment	3,189	3,141	3,163
Goodwill	0	0	0
Other intangible assets	0	0	0
North America
Disclosure of geographical areas [line items]
Net sales	14,060	13,370	12,193
Property, plant and equipment	2,542	2,862	2,719
Goodwill	0	0	0
Other intangible assets	10,675	7,825	11,190
United States
Disclosure of geographical areas [line items]
Net sales	13,465	12,756	11,540
Property, plant and equipment	1,899	2,264	2,238
Goodwill	0	0	0
Other intangible assets	0	0	0
Other countries
Disclosure of geographical areas [line items]
Net sales	12,830	13,674	12,836
Property, plant and equipment	928	1,028	1,061
Goodwill	0	0	0
Other intangible assets	€ 1,468	€ 1,806	€ 2,641

Principal accountants' fees a_3

Principal accountants' fees and services - (Details) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Ernst & Young
Disclosure of audit fees and other services [line items]
Statutory audit of separate and consolidated financial statements	€ 13.9	€ 14
Services other than statutory audit	3.1	1.6
Audit-related services	2.5	0.9
Tax	0	0
Other	0.6	0.7
Total	€ 17	€ 15.6
Statutory audit of separate and consolidated financial statements	82.00%	90.00%
Services other than statutory audit	18.00%	10.00%
Auditor's remuneration, total percentage	100.00%	100.00%
Audit of the financial statements of the parent company and its French subsidiaries	€ 7.4	€ 7.2
Audit-related services charged to the parent company and its French subsidiaries	2.4	0.8
PricewaterhouseCoopers
Disclosure of audit fees and other services [line items]
Statutory audit of separate and consolidated financial statements	15.1	14.6
Services other than statutory audit	0.3	0.2
Audit-related services	0.2	0.2
Tax	0	0
Other	0.1	0
Total	€ 15.4	€ 14.8
Statutory audit of separate and consolidated financial statements	98.00%	99.00%
Services other than statutory audit	2.00%	1.00%
Auditor's remuneration, total percentage	100.00%	100.00%
Audit of the financial statements of the parent company and its French subsidiaries	€ 8.2	€ 7.3
Audit-related services charged to the parent company and its French subsidiaries	€ 0.2	€ 0.1

List of principal companies i_3

List of principal companies included in the consolidation scope during 2020 - Summary of Principal Companies and their Country of Incorporation (Details)	12 Months Ended
	Dec. 31, 2020
Hoechst GmbH | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Deutschland GmbH | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
A. Nattermann & Cie. GmbH | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis GmbH | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Belgium | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Ablynx N.V. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Flanders BVBA | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi A/S | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis S.A. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Oy | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis France | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Winthrop Industrie | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Recherche & Développement | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Groupe | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Chimie | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Francopia | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Participations | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Polyclonals SAS | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Aventis Pharma S.A. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Biotechnology | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Mature IP | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur NVL | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Vaccine Technologies | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur Europe | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis A.E.B.E. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Private Co, Ltd | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	99.60%
Chinoin Private Co. Ltd | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	99.60%
Carraig Insurance DAC | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Ireland Ltd | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Ireland Limited | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Finance Ireland limited | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi S.R.L | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Global Sarl | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Norge AS | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Netherlands B.V. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Europe B.V. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Foreign Participations B.V. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Sp. z.o.o. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Produtos Farmaceuticos Lda | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis, s.r.o. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Romania SRL | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis UK Holdings Limited | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Limited | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Aventis Pharma Limited | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
AO Sanofi Russia | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-aventis Slovakia s.r.o. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi AB | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis (Suisse) SA | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Ilac Sanayi ve Ticaret A.S. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur Asi Ticaret A.S. | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Saglik Urunleri Limited Sirketi | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Limited Liability Company Sanofi-Aventis Ukraine | Europe
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Therapeutic Products Limited Partnership | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Aventis Inc. | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi US Corporation | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Synthorx, Inc | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi US Services Inc. | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis U.S. LLC | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Chattem, Inc. | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Aventisub LLC | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme Corporation | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur Inc. | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
VaxServe, Inc. | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Bioverativ Inc. | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Bioverativ U.S.LLC | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Bioverativ Therapeutics Inc. | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Bristol-Myers Squibb / Sanofi Pharmaceuticals Holding Partnership | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Principia Biopharma Inc | United States
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis South Africa (Pty) Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Algérie | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Arabia Trading Company Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	75.00%
Sanofi-Aventis Argentina S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genzyme de Argentina S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Healthcare Pty Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Australia Pty Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Medley Farmaceutica Ltda | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Canada Inc. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi (Hangzhou) Pharmaceuticals Co., Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi (China) Investment Co., Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi (Beijing) Pharmaceuticals Co.Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur Biologies Co., Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Shenzhen Sanofi pasteur Biological Products Co, Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Genfar S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis de Colombia S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Korea Co. Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Gulf FZE | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis del Ecuador S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Egypt | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	99.80%
Sanofi-Aventis Hong-Kong Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Synthelabo (India) Private Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi India Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	60.40%
Sanofi Healthcare India Private Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	99.90%
PT Aventis Pharma | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	80.00%
Sanofi-Aventis Israël Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi K.K. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
SSP Co.,Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Nichi-Iko K.K. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	51.00%
Sanofi-Aventis (Malaysia) SDN. BHD. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Maroc | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis de Mexico S.A. de C.V. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Winthrop S.A. de C.V. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Pasteur S.A. de C.V. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Pakistan Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	52.90%
Sanofi-Aventis de Panama S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis del Peru S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-aventis Puerto Rico Inc | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Philippines Inc. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis Singapore Pte. Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Aventis Pharma (Manufacturing) Pte. Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Taiwan Co., Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis (Thailand) Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-Aventis de Venezuela S.A. | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi-aventis Vietnam Company Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Shanghai Rongheng Pharmaceutical Co. Ltd | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%
Sanofi Vietnam Shareholding Company Limited | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	85.00%
Azteca Vacunas, S.A. de C.V | Other countries
Disclosure of subsidiaries [line items]
Financial interest in principal fully consolidated companies	100.00%

List of principal companies i_4

List of principal companies included in the consolidation scope during 2020 - Summary of Principal Investments Accounted for Using the Equity Method (Details)	12 Months Ended
	Dec. 31, 2020
GlaxoSmithKline Consumer Healthcare, L.P.
Disclosure of joint operations [line Items]
Financial interest in principal investments accounted for using the equity method	11.70%
Infraserv GmbH & Co. Höchst KG
Disclosure of joint operations [line Items]
Financial interest in principal investments accounted for using the equity method	31.20%
Maphar
Disclosure of joint operations [line Items]
Financial interest in principal investments accounted for using the equity method	48.30%
MCM Vaccine B.V.
Disclosure of joint operations [line Items]
Financial interest in principal investments accounted for using the equity method	50.00%
MSP Vaccine Company (formerly MCM company)
Disclosure of joint operations [line Items]
Financial interest in principal investments accounted for using the equity method	50.00%

Events subsequent to December_2

Events subsequent to December 31, 2020 (Details) - Kymab - Entering into significant commitments or contingent liabilities $ in Millions	Jan. 11, 2021USD ($)
Disclosure of non-adjusting events after reporting period [line items]
Upfront payment	$ 1,100
Commitments related to milestone payments for projects under collaboration agreements	$ 350