Clarus Therapeutics (CRXTQ) S-1 17 Dec 21 IPO registration Financial data

Cover Page

Cover Page	9 Months Ended
	Sep. 30, 2021
Cover [Abstract]
Entity Registrant Name	Clarus Therapeutics Holdings, Inc.
Document Type	S-1
Amendment Flag	false
Entity Central Index Key	0001817944
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Incorporation, State or Country Code	DE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 21,953	$ 7,233	$ 1,656
Accounts receivable, net	6,932	4,400
Inventory	12,480	5,857	6,961
Prepaid expenses and other current assets	3,891	1,846	1,229
Total current assets	45,256	19,336	9,846
Property and equipment, net	66	64	21
Total assets	45,322	19,400	9,867
Current liabilities:
Convertible notes payable to related parties			70,919
Senior notes payable	40,339	41,902
Accounts payable	15,843	12,107	4,379
Accrued expenses	7,373	4,631	1,767
Deferred revenue	827	1,172
Total current liabilities	64,382	59,812	77,065
Derivative warrant liability	6,465		65,006
Convertible notes payable to related parties		77,911
Convertible preferred stock warrant liability			551
Royalty obligation		9,262
Total liabilities	70,847	146,985	142,622
Commitments and contingencies
Redeemable convertible preferred stock, $0.001 par value, 53,340,636 shares authorized at June 30, 2021 and December 31, 2020; 35,537,077 and 36,756,498 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively		198,195	183,513
Stockholders' deficit:
Common stock $0.0001 par value; 125,000,000 shares authorized; 21,725,817 and 4,901,564 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	2	1	1
Additional paid-in capital	291,825
Accumulated deficit	(317,352)	(325,781)	(316,269)
Total stockholders' deficit	(25,525)	(325,780)	(316,268)
Total liabilities, redeemable convertible preferred stock, and stockholders' deficit	$ 45,322	$ 19,400	$ 9,867

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Redemption per share (in Dollars per share)	$ 0.001	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	0	53,340,636	53,340,636
Redeemable convertible preferred stock, shares issued	0	36,756,498	36,756,498
Redeemable convertible preferred stock, shares outstanding	0	36,756,498	36,756,498
Preferred stock, par value (in Dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0
Common stock, par value (in Dollars per share)	$ 0.0001	$ 0.001	$ 0.001
Common stock, shares authorized	125,000,000	56,593,539
Common stock, shares issued	21,725,817	4,901,564
Common stock, shares outstanding	21,725,817	4,901,564
CLARUS THERAPEUTICS [Member]
Common stock, shares authorized		56,593,539	56,593,539
Common stock, shares issued		870,263	870,263
Common stock, shares outstanding		870,263	870,263

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Net product revenue	$ 4,286	$ 2,224	$ 9,395	$ 3,943	$ 6,369
Cost of product sales	510	257	1,431	8,328	8,687
Gross profit (loss)	3,776	1,967	7,964	(4,385)	(2,318)
Operating expenses:
Sales and marketing	7,550	8,733	25,017	23,557	29,515	$ 7,374
General and administrative	3,384	3,040	12,316	8,261	11,937	7,414
Research and development	1,275	1,437	3,093	2,818	3,407	3,088
Total operating expenses	12,209	13,210	40,426	34,636
Loss from operations	(8,433)	(11,243)	(32,462)	(39,021)	(47,177)	(17,876)
Other (expense) income, net:
Change in fair value of warrant liability and derivative, net	7,610	20,939	7,610	53,854	66,891	13
Interest income	1	1	1	24	25	79
Interest expense	(4,447)	(4,291)	(13,964)	(10,790)	(15,394)	(23,866)
Total other (expense) income, net	5,664	16,649	(3,853)	43,088	51,522	(23,774)
Litigation settlement	2,500		2,500
Net (loss) income before income taxes	(2,769)	5,406	(36,315)	4,067	4,345	(41,650)
Provision for income taxes
Net (loss) income	(2,769)	5,406	(36,315)	4,067	4,345	(41,650)
Net (loss) income attributable to common stockholders, basic (Note 13)	(2,357)	5,396	(35,903)	(4,059)
Net loss attributable to common stockholders, diluted (Note 13)	$ (2,357)	$ (13,743)	$ (35,903)	$ (44,279)
Net (loss) income per common share attributable to common stockholders, basic	$ (0.26)	$ 1.10	$ (5.68)	$ 0.83
Net loss per common share attributable to common stockholders, diluted (Note 13) (in Dollars per share)	$ (0.26)	$ (0.63)	$ (5.68)	$ (2.03)
Accretion of preferred stock					(14,682)	(13,594)
Net loss attributable to common stockholders – basic and diluted					$ (10,337)	$ (55,244)
Weighted-average common shares used in net loss per share attributable to common stockholders, diluted (Note 13)	9,153,848	21,828,570	6,318,992	21,828,570
Weighted-average common shares used in net (loss) income per share attributable to common stockholders, basic (Note 13)	9,153,848	4,901,564	6,318,992	4,901,564
Weighted average shares outstanding of common stock, basic and diluted (in Shares)					870,263	870,263
Basic and diluted net (loss) income per share, common stock (in Dollars per share)					$ (11.88)	$ (63.48)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands		Total	Previously Reported [Member]	Adjusted	Common Stock	Common StockPreviously Reported [Member]	Additional Paid-In Capital	Additional Paid-In CapitalPreviously Reported [Member]	Additional Paid-In CapitalAdjusted	Accumulated Deficit	Accumulated DeficitPreviously Reported [Member]	Accumulated DeficitAdjusted	Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred StockPreviously Reported [Member]
Balance at Dec. 31, 2018		$ (261,383)			$ 1					$ (261,384)			$ 169,919
Balance (in Shares) at Dec. 31, 2018					870,263								36,756,498
Accretion of redeemable convertible preferred stock to redemption value		(13,594)					$ (359)			(13,235)			$ 13,594
Stock-based compensation		359					359
Net loss/income		(41,650)								(41,650)
Balance (in Shares) at Dec. 31, 2019					870,263	870,263							36,756,498	36,756,498
Balance at Dec. 31, 2019		(316,268)	$ (316,268)		$ 1	$ 1		$ 0		(316,269)	$ (316,269)		$ 183,513	$ 183,513
Stock-based compensation		74					74
Net loss/income		(11,894)								(11,894)
Retroactive application of the recapitalization due to the Business Combination (Note 3) (Shares)					4,031,301								(36,756,498)
Retroactive application of the recapitalization due to the Business Combination (Note 3) (Value)			183,513					160,363			23,150		$ (183,513)
Balance (in Shares) at Mar. 31, 2020					4,901,564								0
Balance at Mar. 31, 2020		(144,575)	(132,755)		$ 1		160,437	160,363		(305,013)	(293,119)		$ 0
Balance at Dec. 31, 2019		(316,268)	(316,268)		$ 1	$ 1		0		(316,269)	(316,269)		$ 183,513	$ 183,513
Balance (in Shares) at Dec. 31, 2019					870,263	870,263							36,756,498	36,756,498
Issuance of Class B common stock to related party		(14,682)					(825)			(13,857)			$ 14,682
Stock-based compensation		825					825
Net loss/income		4,345								4,345
Balance (in Shares) at Dec. 31, 2020					870,263	870,263							36,756,498	36,756,498
Balance at Dec. 31, 2020		(325,780)	(325,780)		$ 1	$ 1		0		(325,781)	(325,781)		$ 198,195	$ 198,195
Balance at Mar. 31, 2020		(144,575)	(132,755)		$ 1		160,437	160,363		(305,013)	(293,119)		$ 0
Balance (in Shares) at Mar. 31, 2020					4,901,564								0
Stock-based compensation		70					70
Net loss/income		10,555								10,555
Balance (in Shares) at Jun. 30, 2020					4,901,564								0
Balance at Jun. 30, 2020		(133,950)			$ 1		160,507			(294,458)			$ 0
Stock-based compensation		90					90
Net loss/income		5,406								5,406
Balance (in Shares) at Sep. 30, 2020					4,901,564								0
Balance at Sep. 30, 2020		(128,454)			$ 1		160,597			(289,052)			$ 0
Balance at Dec. 31, 2020		(325,780)	(325,780)		$ 1	$ 1		0		(325,781)	(325,781)		$ 198,195	$ 198,195
Balance (in Shares) at Dec. 31, 2020					870,263	870,263							36,756,498	36,756,498
Conversion of convertible notes payable into Series D redeemable convertible preferred stock		11,829					11,829
Stock-based compensation		176					176
Net loss/income		(15,429)								(15,429)
Retroactive application of recapitalization related to 2021 activity (1)	[1]						(7,737)			7,737
Retroactive application of the recapitalization due to the Business Combination (Note 3) (Shares)					4,031,301								(36,756,498)
Retroactive application of the recapitalization due to the Business Combination (Note 3) (Value)		189,659					152,653			37,006			$ (198,195)
Balance (in Shares) at Mar. 31, 2021					4,901,564								0
Balance at Mar. 31, 2021		(139,545)		$ (136,121)	$ 1		156,921		$ 152,653	(296,467)		$ (288,775)	$ 0
Balance at Dec. 31, 2020		(325,780)	$ (325,780)		$ 1	$ 1		$ 0		(325,781)	$ (325,781)		$ 198,195	$ 198,195
Balance (in Shares) at Dec. 31, 2020					870,263	870,263							36,756,498	36,756,498
Balance (in Shares) at Sep. 30, 2021					21,725,817								0
Balance at Sep. 30, 2021		(25,525)			$ 2		291,825			(317,352)			$ 0
Balance at Mar. 31, 2021		(139,545)		$ (136,121)	$ 1		156,921		$ 152,653	(296,467)		$ (288,775)	$ 0
Balance (in Shares) at Mar. 31, 2021					4,901,564								0
Stock-based compensation		177					177
Net loss/income		(18,117)								(18,117)
Balance (in Shares) at Jun. 30, 2021					4,901,564								0
Balance at Jun. 30, 2021		(157,485)			$ 1		157,098			(314,584)			$ 0
Stock-based compensation		207					207
Net loss/income		(2,769)								(2,769)
Recapitalization on September 9, 2021 , (Shares)					12,984,784
Recapitalization on September 9, 2021 , (Value)		117,513			$ 1		117,512
Proceeds from Blue Water Acquisition Corp. in Business Combination		17,008					17,008
Proceeds from Blue Water Acquisition Corp. in Business Combination (in Shares)					3,839,469
Balance (in Shares) at Sep. 30, 2021					21,725,817								0
Balance at Sep. 30, 2021		$ (25,525)			$ 2		$ 291,825			$ (317,352)			$ 0
[1]	Relates to reversal of 2021 accretion recorded on the redeemable convertible preferred stock prior to the merger, as the redeemable convertible preferred stock has been retroactively restated to give effect to the reverse recapitalization.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income (loss)	$ (36,315)	$ 4,067	$ 4,345	$ (41,650)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Non-cash interest expense related to debt financing and royalty obligation	11,137	7,856	12,459	9,005
Settlement of interest with payment-in-kind note	3,125	0
Non-cash gain on partial extinguishment of senior notes	(296)	0
Change in fair value of warrant liability	(7,610)	(541)	(551)	(138)
Change in fair value of derivative liability	0	(53,313)	(66,340)	14,986
Stock-based compensation expense	560	234	825	359
Depreciation	18	14	18	4
Changes in operating assets and liabilities:
Accounts receivable	(2,532)	(3,451)	(4,400)
Inventory	(6,622)	746	1,104	(6,961)
Prepaid expenses and other current assets	(2,048)	(734)	(804)	(939)
Accounts payable	3,736	7,165	7,728	4,035
Accrued expenses	2,740	1,677	2,864	1,584
Deferred revenue	(345)	619	1,172
Net cash used in operating activities	(34,452)	(35,661)	(41,580)	(19,715)
Investing activities
Purchases of property and equipment	(20)	(62)	(63)	(21)
Net cash used in investing activities	(20)	(62)	(63)	(21)
Financing activities
Proceeds from issuance of convertible notes payable	23,592	1,611	1,611	18,389
Proceeds from business combination, net	17,008	0
Proceeds from issuance of senior notes payable	8,592	49,125	49,125
Proceeds from PPP loan		500	488
Repayment of PPP loan		(500)	(488)
Debt issuance costs		(3,516)	(3,516)	(29)
Net cash provided by financing activities	49,192	47,220	47,220	18,360
Net increase in cash and cash equivalents	14,720	11,497	5,577	(1,376)
Cash and cash equivalents — beginning of period	7,233	1,656	1,656	3,032
Cash and cash equivalents — end of period	21,953	13,153	7,233	1,656
Supplemental disclosure of cash flow information:
Cash paid for interest			3,125
Supplemental disclosure of non-cash investing and financing activities:
Conversion of convertible notes payable into Series D redeemable convertible preferred stock	3,360	0
Accretion of redeemable convertible preferred stock to redemption value, including dividends on preferred stock			$ 14,682	$ 13,594
Conversion of Series D redeemable convertible preferred stock into Old Clarus common stock prior to the recapitalization	11,829	0
Senior secured note principal and royalty obligation balance conversion to shares of common stock upon merger	28,254	0
Convertible notes principal and accrued interest balance conversion to shares of common stock upon merger	103,333	0
Conversion of Series D redeemable convertible preferred stock into common stock	189,659	0
Value of warrants assumed upon merger (Note 3)	$ 14,075	$ 0

Organization and Description of

Organization and Description of Business Operations	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Description of Organization Business Operations and Basis of Presentation [Line Items]
Description of Organization, Business Operations and Basis of Presentation	1. Organization and Description of Business Operations Clarus Therapeutics Holdings, Inc. (together with its consolidated subsidiary, the “Company” or “Clarus”) formerly known as Blue Water Acquisition Corp. (“Blue Water”), was incorporated in Delaware on May 22, 2020, Blue Water was a Special Purpose Acquisition Company (“SPAC”) formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination with one or more businesses. The registration statement for the Company’s Initial Public Offering (“IPO”) was declared effective on December 15, 2020. On December 17, 2020, the Company consummated its IPO of 5,750,000 units (the “Units” and, with respect to the Class A common stock included in the Units being offered, the “Public Shares”), including 750,000 additional Units to cover over-allotments (the “Over-Allotment Units”), at $10.00 per Unit, generating gross proceeds of $57.5 million, and incurring offering costs of approximately $3.7 million, of which approximately $2.0 million was for deferred underwriting commissions. Simultaneously with the closing of the IPO, the Company consummated the private placement (“Private Placement”) of 3,445,000 warrants (each, a “Private Placement Warrant” and collectively, the “Private Placement Warrants”) at a price of $1.00 per Private Placement Warrant to Blue Water Sponsor LLC (the “Sponsor”), generating proceeds of approximately $3.4 million. Upon the closing of the IPO and the Private Placement, approximately $58.7 million ($10.20 per Unit) of the net proceeds of the IPO and certain of the proceeds of the Private Placement was held in a trust account (“Trust Account”) located in the United States with Continental Stock Transfer & Trust Company acting as trustee, and were invested only in U.S. “government securities” within the meaning of Section 2(a)(16) of the U.S. Investment Company Act of 1940, as amended (the “Investment Company Act”) having a maturity of 185 days or less or in money market funds meeting certain conditions under Rule 2a-7 Merger On September 9, 2021 (the “Closing Date”), the Company, and Blue Water Merger Sub Corp., a Delaware corporation and wholly-owned subsidiary of the Company (“Merger Sub”), consummated the previously announced merger, pursuant to the Agreement and Plan of Merger, dated as of April 27, 2021 (the “Merger Agreement”), with Clarus Therapeutics, Inc., a Delaware corporation (“Old Clarus”), pursuant to which, subject to the terms and conditions set forth in the Merger Agreement, Merger Sub merged with and into Old Clarus, with Old Clarus surviving as a wholly-owned subsidiary of the Company, and with Old Clarus’s equity holders’ and convertible debt holders equity interests converted into the right to receive shares of the Company’s common stock or else be canceled, retired and terminated without consideration, as provided in the Merger Agreement (the “Merger”). Upon the consummation of the business combination, Blue Water changed its name to “Clarus Therapeutics Holdings, Inc.” In connection with the Merger, Old Clarus’s convertible noteholders and senior secured noteholders provided $25.0 million in additional capital to Old Clarus following the announcement of the execution of the Merger Agreement. All such proceeds plus accrued interest converted to shares of the Company’s common stock at a price of $10.00 per share, resulting in 2,549,939 shares issued on the Closing Date. The additional capital of $25.0 million was received by Old Clarus prior to the Closing Date. Together with Blue Water’s cash resources and additional capital, the Company received net proceeds from the Merger (not including the $25.0 million of additional capital) of approximately $17.0 million. At the effective time of the Merger (the “Effective Time”), shares of Old Clarus’s redeemable convertible Series D Preferred Stock issued and outstanding and all principal and accrued interest under Old Clarus’s Series D convertible notes immediately prior to the Effective Time converted into 13,431,410 shares of the Company’s common stock at a price of $10.20 per share. Additionally, $10.0 million of debt related to Old Clarus’ senior secured notes, including certain royalty rights was exchanged for an aggregate of 1,500,000 shares of the Company’s common stock. Further, under a share allocation agreement entered into by Blue Water and Old Clarus on September 1, 2021, as part of the Merger, an additional 405,000 shares of the Company’s common stock were allocated to the senior secured noteholders (as further described in Note 7), which included 270,000 shares reallocated to the senior secured note holders from Old Clarus’s equity holders and 135,000 shares from the Blue Water founder that were transferred from the Sponsor pursuant to the share allocation agreement. All unexpired, outstanding Series D Warrants of Old Clarus remained outstanding and became exercisable for shares of the Company’s common stock, subject to adjustment in accordance with the Merger exchange ratio. All other series of Old Clarus preferred stock, common stock and stock options were cancelled and extinguished upon completion of the Merger. In addition, Old Clarus’s existing equity incentive plans were terminated. For additional information on the business combination, please refer to Note 3, Business Combination Description of Business Following the Merger The Company operates as a pharmaceutical company post-merger focused on the commercialization of JATENZO ® The Company is subject to risks and uncertainties associated with any pharmaceutical company that is transitioning from the development to commercial stage. Since inception, Old Clarus incurred substantial operating losses due to substantial product development and commercialization expenditures. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of JATENZO, is cash flow positive from operations, or enters into cash flow positive business development transactions. The Company’s U.S. patent portfolio on JATENZO currently includes five issued patents and has recently received two notices of allowance from the United States Patent and Trademark Office (USPTO) for claims that cover its oral testosterone replacement product, JATENZO. The issued U.S. patents contain claims to both pharmaceutical compositions and methods of treatment using the Company’s proprietary pharmaceutical composition and all are listed in the FDA Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. In addition, the Company has several patent applications pending in the United States and other countries that, if issued, will cover pharmaceutical compositions, methods of treatment and other features of JATENZO, and have the potential to extend patent coverage beyond 2030. Liquidity and Going Concern The Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the condensed financial statements are issued. Since its inception, Old Clarus has devoted substantially all its efforts to business planning, clinical development, commercial planning and raising capital. Old Clarus, and since the Merger, the Company has incurred significant losses from operations since inception and has an accumulated deficit of $317.4 million as of September 30, 2021. Further, as of September 30, 2021, the Company had a working capital deficit of $19.1 million. In addition to the consummation of the Merger and the related investment, the Company plans to seek additional funding through the expansion of its commercial efforts to grow JATENZO and its operating cash flow, business development efforts to out-license Debt If the Company is unable to obtain funding or generate operating cash flow, the Company will be forced to delay, reduce or eliminate some or all of its product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. Based on its recurring losses from operations incurred since inception, expectation of continuing operating losses for the foreseeable future, and need to raise additional capital to finance its future operations, as of the issuance date of the condensed consolidated financial statements for the nine months ended September 30, 2021, the Company has concluded that its cash and cash equivalents will not be sufficient to fund its operating expenses, capital expenditure requirements and debt service payments through at least twelve months from the date that these condensed consolidated financial statements are available to be issued and that there is substantial doubt about the Company’s ability to continue as a going concern. The accompanying condensed financial statements do not include any adjustments that might result from the outcome of this uncertainty. Accordingly, the condensed financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Impact of the COVID-19 The business disruptions associated with the COVID-19 Debt COVID-19 The Company is closely monitoring the evolving impact of the pandemic on all aspects of its business. The Company has implemented a number of measures designed to protect the health and safety of its employees, support its customers and promote business continuity. The Company is also actively reviewing and implementing cost-saving measures, including discontinuing or delaying all non-essential COVID-19	1. Organization and Description of Business Operations Clarus Therapeutics, Inc. (the “Company” or “Clarus”) is a specialty pharmaceutical company focused on the commercialization of JATENZO, the first and only oral testosterone (“T”) replacement, or testosterone replacement therapy (“TRT”), of its kind approved by the U.S. Food and Drug Administration, or FDA. The FDA completed its review of the Company’s New Drug Application and approved JATENZO for marketing on March 27, 2019. The Company commercially launched JATENZO on February 10, 2020. JATENZO is the Company’s sole source of revenue and sales are exclusively within the United States. Management remains committed to the product’s commercial success. The Company was founded in 2004 and is located and headquartered in Northbrook, Illinois. The Company is subject to risks and uncertainties associated with any pharmaceutical company that is transitioning from the development to commercial stage. Since inception, the Company has incurred substantial operating losses due to substantial product development and commercialization expenditures. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of JATENZO, is cash flow positive from operations, or enters into cash flow positive business development transactions. Liquidity and Going Concern The Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued. Since its inception, the Company has devoted substantially all its efforts to business planning, clinical development, commercial planning and raising capital. The Company has incurred losses since inception and has an accumulated deficit of $325.8 million as of December 31, 2020, including $94.0 million of cumulative accretion on the Series A Redeemable Convertible Preferred Stock (“Series A Preferred Stock”), the Series B Redeemable Convertible Preferred Stock (“Series B Preferred Stock”), the Series C Redeemable Convertible Preferred Stock (“Series C Preferred Stock”) and the Series D Redeemable Convertible Preferred Stock (“Series D Preferred Stock”), collectively, Preferred Stock, and $97.6 million of cumulative non-cash The Company is seeking to complete a merger with a newly-formed Special Purpose Acquisition Company (“SPAC”), whereby the Company will become a 100% owned subsidiary of the SPAC. In addition, current Clarus stakeholders will invest an additional $25.0 million in Clarus before the close of this transaction (Note 15). In addition to pursuing consummation of the SPAC merger and the related investment, the Company plans to seek additional funding through the expansion of its commercial efforts to grow JATENZO and its operating cash flow, business development efforts to out-license Debt If the Company is unable to obtain funding or generate operating cash flow, the Company will be forced to delay, reduce or eliminate some or all of its product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. Based on its recurring losses from operations incurred since inception, expectation of continuing operating losses for the foreseeable future, and need to raise additional capital to finance its future operations, as of the issuance date of the financial statements for the year ended December 31, 2020, the Company has concluded that its cash and cash equivalents will not be sufficient to fund its operating expenses, capital expenditure requirements and debt service payments through at least twelve months from the date that these financial statements are available to be issued and that there is substantial doubt about the Company’s ability to continue as a going concern. The accompanying financial statements do not include any adjustments that might result from the outcome of this uncertainty. Accordingly, the financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Impact of the COVID-19 The business disruptions associated with the COVID-19 Debt COVID-19 The Company is closely monitoring the evolving impact of the pandemic on all aspects of its business. The Company has implemented a number of measures designed to protect the health and safety of its employees, support its customers and promote business continuity. The Company is also actively reviewing and implementing cost-saving measures including discontinuing or delaying all non-essential COVID-19

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Line Items]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Significant Accounting Policies The Company’s significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2020 and the notes thereto, which are included in the final prospectus filed with the SEC pursuant to Rule 424(b)(3) on October 7, 2021. Since the date of those consolidated financial statements, there have been no material changes to its significant accounting policies, except as noted below. Basis of Presentation The condensed consolidated financial statements and accompanying notes have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments necessary to fairly present the financial position of the Company as of September 30, 2021 and December 31, 2020, the results of operations for the three and nine months ended September 30, 2021 and 2020 and its cash flows for the nine months ended September 30, 2021 and 2020 have been included and are of a normal, recurring nature except as otherwise disclosed. These condensed consolidated financial statements and notes thereto have been prepared under the presumption that users of the financial information have either read or have access to the audited financial statements for the latest year ended December 31, 2020. As a result of the Merger, the shares and corresponding capital amounts and loss per share related to Old Clarus’s outstanding convertible preferred stock and common stock prior to the Merger have been retroactively restated to reflect the actual shares for which the Series D preferred stock converted into as a result of the conversion terms in the Merger Agreement. For additional information on the Business Combination, please refer to Note 3, Business Combination Use of Estimates Preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenues and expenses during the reporting period covered by the condensed financial statements and accompanying notes. The most significant estimates relate to determination of fair value of the Company’s common stock and common stock warrants, stock-based compensation, notes, royalty obligation and the valuation of embedded derivatives. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, and records adjustments when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from those estimates. Derivative warrant liabilities The Company does not use derivative instruments to hedge exposures to cash flow, market, or foreign currency risks. The Company evaluates all of its financial instruments, including issued stock purchase warrants, to determine if such instruments are liabilities, derivatives or contain features that qualify as embedded derivatives, pursuant to ASC 480 and ASC 815 Derivatives and Hedging re-assessed The Private Placement Warrants are recognized as derivative liabilities in accordance with ASC 815. Accordingly, the Company recognizes the warrant instruments as liabilities at fair value and adjusts the instruments to fair value at each reporting period. The fair value of the Private Placement warrants has been estimated using a modified Monte Carlo simulation model at inception and subsequently at each measurement date using the Black-Scholes model. The liabilities are subject to re-measurement The fair value of warrants issued in connection with the IPO were initially measured at fair value using a Monte Carlo simulation model and have subsequently been measured based on the listed market price of such warrants. Net Income (Loss) Per Share Basic net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the period. Diluted net income (loss) per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common stock. Net income (loss) per share attributable to common stockholders is calculated using the two-class as-converted When considering the impact of the convertible equity instruments, diluted net income (loss) per share is computed using the more dilutive of (a) the two-class if-converted	2. Summary of Significant Accounting Policies Basis of Presentation The financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Reclassifications Certain reclassifications have been made to the Company’s prior year financial statements to conform to the Company’s current year presentation. These reclassifications had no effect on the Company’s previously reported results of operations or accumulated deficit. Segment Information The Company’s chief operating decision maker manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. All of the Company’s long-lived assets are held in the United States. Use of Estimates Preparation of the financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period covered by the financial statements and accompanying notes. The most significant estimates relate to determination of fair value of the Company’s common stock and common stock warrants, stock-based compensation, notes, royalty obligation and the valuation of embedded derivatives. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, and records adjustments when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from those estimates. Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The three levels of inputs that may be used to measure fair value are defined below: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3: Unobservable inputs for the asset or liability (i.e. supported by little or no market activity). Level 3 inputs include management’s own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk). To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Cash and Cash Equivalents Cash and cash equivalents and represent cash and highly liquid investments with an original contractual maturity at the date of purchase of three months or less. As of December 31, 2020 and 2019, cash and cash equivalents included government-backed money market funds. Concentrations of Risk Substantially all of the Company’s cash and money market funds are held with a single financial institution. Due to its size, the Company believes this financial institution represents minimal credit risk. Deposits in this institution may exceed the amount of insurance provided on such deposits by the Federal Deposit Insurance Corporation for U.S. institutions. The Company has not experienced any losses on its deposits of cash and cash equivalents. Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company’s accounts receivable balance is compromised solely from transactions with the Company’s single third-party logistics provider, or 3PL. The Company monitors economic conditions to identify facts or circumstances that may indicate that any of its accounts receivable are at risk of collection. The Company depends on two third-party suppliers for its supply of T-undecanoate Accounts Receivable, Net Accounts receivable are stated at net realizable value. On a periodic basis, management evaluates its accounts receivable and determines whether to provide an allowance or if any accounts should be written off based on a past history of write-offs, collections and current credit conditions. A receivable is considered past due if the Company has not received payments based on agreed-upon terms. The Company generally does not require any security or collateral to support its receivables. The Company performs ongoing evaluations of its customers. Inventory Inventory is stated at the lower of cost or net realizable value. Cost is determined using the first-in, first-out Property and Equipment, net Property and equipment are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the respective assets, as follows: Asset Class Estimated Computer and office equipment 3 years Furniture and fixtures 7 years Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations. Repair and maintenance costs are charged to expense as incurred Impairment of Long-Lived Assets The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset group may not be recoverable. There were no charges as a result of impairment losses for the years ended December 31, 2020 or 2019. Deferred Financing Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process in-process Redeemable Convertible Preferred Stock The Company has adopted current accounting guidance in regard to accounting for certain financial instruments with characteristics of both liabilities and equity and for the classification and measurement of redeemable securities. This guidance requires companies with mandatorily redeemable features in their equity instruments to be classified separately from equity. The Company measures these instruments by recognizing changes in redemption value immediately as they occur and adjust the carrying amount of the instrument to equal the redemption value at the end of each reporting period. In accordance with this guidance, the Series A Preferred Stock, Series B Preferred Stock, Series C Preferred Stock and Series D Preferred Stock have been classified separately from equity in the accompanying balance sheets. Revenue Recognition In accordance with ASC 606, Revenue from Contracts with Customers has assessed the existence of a significant financing component in the agreements with its customers. The trade payment terms with its customers do not exceed one year and therefore, no amount of consideration has been allocated as a financing component. Taxes collected related to product sales are remitted to governmental authorities and are excluded from revenue. Net Product Sales The Company began selling JATENZO in February 2020, in the United States through a 3PL which takes title and control of the goods. The 3PL distributes the product to wholesale distributors (collectively the “Distributors”), with whom the Company has entered into formal agreements for delivery to retail pharmacies. The Company has also entered into arrangements with payors that provide government mandated and/or privately negotiated rebates, chargebacks and discounts for the purchase of the Company’s products. The Company recognizes revenue on sales of JATENZO when the customer obtains control of the product, which occurs at a point in time, typically upon delivery. Product revenues are recorded at the product’s wholesale acquisition costs, net of applicable reserves for variable consideration that are offered within contracts between the Company and its customers, wholesale distributors, payors, and other indirect customers relating to the sale of JATENZO. Components of variable consideration include government and commercial contract rebates, product returns, chargebacks, commercial co-payment The amount of variable consideration which is included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognition under contracts will not occur in a future period. The Company’s analyses contemplate the application of the constraint in accordance with ASC 606. Actual amounts of consideration ultimately received may differ from its estimates. If actual results in the future vary from its estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. Cost of Product Sales Cost of product sales include manufacturing and distribution costs, the cost of drug substance, FDA program fees and a reserve for short-dated, obsolete inventory. The Company began capitalizing inventory upon FDA approval of JANTENZO ® Research and Development Expenses Research and development expenses include salaries and benefits, clinical trials costs, contract services and manufacturing development costs. Research and development expenses are charged to operations as they are incurred. The Company follows the provisions of the Research and Development Topic of the Codification which requires the Company to defer and capitalize nonrefundable advance payments made for goods or services to be used in research and development activities until the goods have been delivered or the related services have been performed. If the goods are no longer expected to be delivered or the services are no longer expected to be performed, the Company would be required to expense the related capitalized advance payments. The Company had no capitalized nonrefundable advance payments and no refundable advance payments as of December 31, 2020 or 2019. Leases The Company leases office space and recognizes related rent expense on a straight-line basis over the term of the lease. Stock-Based Compensation The Company accounts for all stock-based compensation awards granted as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, restricted for vesting conditions. The measurement date for awards is the date of grant, and stock-based compensation costs are recognized as expense over the requisite service period, which is generally the vesting period, on a straight-line basis. Stock-based compensation expense is classified in the accompanying statements of operations based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are recorded as they occur. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. Patents and Trademarks All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty of the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the statement of operations. Basic and Diluted Loss per Share Basic and diluted net loss per common share is determined by dividing net loss attributable to common stockholders by the weighted average common shares outstanding. Basic net loss per share is determined using the weighted average number of shares of common stock outstanding during each period. Diluted net loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible preferred stock, warrants and stock options, which would result in the issuance of incremental shares of common stock. The computation of diluted net loss per shares does not include the conversion of securities that would have an anti-dilutive effect. The basic and diluted computations of net loss per share for the Company are the same because the effects of the Company’s convertible securities would be anti-dilutive. See Note 13, Net Loss per Share Comprehensive Loss The Company’s comprehensive loss was the same as its reported net loss for all periods presented. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, the Company determines deferred tax assets and liabilities on the basis of the differences between the financial statement and tax bases of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that it believes that these assets are more likely than not to be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning The Company records uncertain tax positions in accordance with ASC 740 on the basis of a two-step more-likely-than-not The Company recognizes interest and penalties related to unrecognized tax benefits on the income tax expense line in the accompanying statement of operations. As of December 31, 2020 and 2019, no accrued interest or penalties are included on the related tax liability line in the balance sheet. Emerging Growth Company Status The Company is expected to be an “emerging growth company” (“EGC”) upon merger, as defined in the Jumpstart Our Business Startups Act (“JOBS Act”) and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not EGCs. The Company may take advantage of these exemptions until it is no longer an EGC under Section 107 of the JOBS Act, which provides that an EGC can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company expects to elect to avail itself of the extended transition period and, therefore, while the Company is an EGC it will not be subject to new or revised accounting standards the same time that they become applicable to other public companies that are not EGCs, unless it chooses to early adopt a new or revised accounting standard. Recently Adopted Accounting Pronouncements In January 2016, the FASB issued ASU 2016-01, Financial Instruments — Overall (Subtopic 825-10): 2016-01”). 2016-01 2016-01 Recently Issued Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) 2016-02”) . ASU 2016-02, right-of-use In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments 2016-13”), 2016-13 available-for-sale 2016-13 2016-13 2016-13 In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) 2019-12”) : Simplifying the Accounting for Income Taxes, In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848), Facilitation of the Effects of Reference Rate Reform on Financial Reporting 2020-4”), 2020-04 2020-04 In June 2020, the FASB issued ASU 2020-06, Debt — Debt with Conversion and Other Options (Subtopic 470-20) 815-40): 2020-06”). ASU 2020-06 2020-06

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2021
Business Combination, Description [Abstract]
Business Combination	3. Business Combination On September 9, 2021, the business combination between Blue Water Merger Sub and Old Clarus, was consummated, pursuant to the Merger Agreement dated April 27, 2021 (the “Business Combination”). Upon the closing of the Business Combination, Merger Sub merged with and into Old Clarus, with Old Clarus as the surviving company in the Merger and becoming a wholly-owned subsidiary of the Company. Upon the closing of the Business Combination, Blue Water changed its name to “Clarus Therapeutics Holdings, Inc.” The Business Combination is accounted for as a reverse recapitalization in accordance with U.S. generally accepted accounting principles (“GAAP”). Under this method of accounting, Blue Water is treated as the acquired company and Old Clarus is treated as the acquirer for financial statement reporting and accounting purposes. As a result, the historical operations of Old Clarus are deemed to be those of the Company. Therefore, the financial statements included in this report reflect (i) the historical operating results of Old Clarus prior to the Business Combination; (ii) the combined results of the Blue Water and Old Clarus following the Business Combination on September 9, 2021; (iii) the assets and liabilities of Old Clarus at their historical cost; and (iv) the Company’s equity structure for all periods presented. The recapitalization of the number of shares of common stock attributable to the Business Combination is reflected retroactively to the earliest period presented and will be utilized for calculating earnings per share in all prior periods presented. No step-up The aggregate consideration issued or reserved for issuance to Old Clarus securityholders upon the closing of the Merger was 17,886,349 shares of Company common stock. The 17,886,349 shares includes an aggregate of 1,905,000 shares of common stock (which included the 405,000 shares of the Company’s common stock that were allocated to the senior secured noteholders pursuant to the share allocation agreement , as described in Note 7, of which 270,000 shares reallocated to the senior secured note holders from Old Clarus’s equity holders and 135,000 shares from the Blue Water founder that were transferred from the Sponsor), which were issued to the holders of Old Clarus’ senior secured notes in connection with the Merger Agreement and were in exchange for $18.6 million of aggregate principal amount of the senior secured notes and certain outstanding royalty rights. Within the aggregate shares issued to Old Clarus securityholders is also 2,549,939 shares of common stock at $10.00 per share, that were issued to Old Clarus equity holders for the private placement Additional Closing Shares, of which such noteholders provided gross proceeds of $25.0 million, from the date of Merger Agreement signature through Effective Time. Further, 4,901,564 shares of common stock were issued to the holders of the Series D Preferred Stock and 8,529,846 shares of common stock were issued to the holders of Old Clarus convertible notes that were issued and outstanding prior to the Effective Time. In connection with the Business Combination, the Company incurred equity issuance costs and other costs considered direct and incremental to the transaction totaling $8.4 million, consisting of legal, accounting, and financial advisory and other professional fees. These amounts are reflected within additional paid in capital in the condensed consolidated balance sheet as of September 30, 2021. Summary of Net Proceeds The following table summarizes the elements of the net proceeds from the Business Combination as of September 30, 2021 (in thousands): Cash – Blue Water Trust Account and cash (net of redemptions) $ 25,394 Less: Equity issuance costs and other costs paid prior to September 30, 2021 (8,386 ) Net Proceeds from the Business Combination $ 17,008 Summary of Shares Issued The following table summarizes the number of shares of Common Stock outstanding immediately following the consummation of the Business Combination: Blue Water shares outstanding prior to the Business Combination 3,839,468 Conversion of Old Clarus Series D Preferred Stock 4,901,564 Conversion of Old Clarus convertible notes 8,529,846 Conversion of additional capital provided by Old Clarus convertible note and senior note holders 2,549,939 Conversion of Senior Secured Note principal and royalty rights 1,905,000 Total shares of the Company’s common stock outstanding immediately following the Business Combination 21,725,817 The following table summarizes the impact of the transaction on the condensed consolidated statement of stockholder’s deficit as of September 9, 2021: Additional Paid Conversion of senior notes and royalty obligation carrying value $ 28,254 Conversion of Old Clarus convertible notes carrying value 103,333 Assumption of private placement warrant liabilities (14,075 ) Total reverse recapitalization impact on statement of equity $ 117,512

Fair Value Measurements

Fair Value Measurements	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Fair Value Measurements [Line Items]
Fair Value Measurements	4. Fair Value Measurements The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: September 30, 2021 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 20,001 $ 20,001 $ — $ — Total assets $ 20,001 $ 20,001 $ — $ — Liabilities Private placement warrant liability $ 6,465 $ — $ — $ 6,465 Total Liabilities $ 6,465 $ — $ — $ 6,465 December 31, 2020 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 7,205 $ 7,205 $ — $ — Total assets $ 7,205 $ 7,205 $ — $ — During the nine months ended September 30, 2021 and the year ended December 31, 2020, there were no transfers between levels. As of September 30, 2021 and December 31, 2020, the Company’s cash equivalents consisted of money market funds, classified as Level 1 financial assets, as these assets are valued using quoted market prices in active markets without any valuation adjustment. There were no transfers or reclassifications between Level 1, Level 2 and Level 3 financial assets during the three and nine months ended September 30, 2021. As of September 30, 2021 and December 31, 2020, the Company had Level 3 financial liabilities that were measured at fair value on a recurring basis. The Company’s Warrant Liabilities and Derivative Liability (defined below) are carried at fair value, determined using Level 3 inputs in the fair value hierarchy. As of September 30, 2021 the Warrant Liabilities were valued at $6.4 million, and as of December 31, 2020, the Warrant Liability and Derivative Liability were valued at zero. The carrying amounts reported in the accompanying balance sheets for cash, accounts receivable, accounts payable and accrued expenses approximate their fair value based on the short-term nature of these instruments. The carrying value of long-term and short-term debt, taking into consideration debt discounts and related derivative instruments, is estimated to approximate fair value. Warrant Liabilities In conjunction with a previous loan agreement of Old Clarus that was fully paid in 2017, certain lenders were granted warrants (or the “Series D Warrants”), to purchase a total of 183,438 shares of Series D Preferred Stock at an exercise price of $4.50 per share. The expiration date of the warrants is the earlier of July 14, 2021 for 122,292 shares and April 9, 2023 for 61,146 shares, or three years from the effective date of a registration statement for an initial public offering of Old Clarus’s stock. At December 31, 2020 the Warrant Liability was valued at zero. The Series D Warrants outstanding immediately prior to the Effective Time to purchase 61,146 shares of the Series D Preferred Stock were converted into warrants to purchase 9,246 shares of the Company’s common stock at an exercise price of $29.74 per share and the expiration date remains April 9, 2023. At the Effective Time and immediately following the completion of the Business Combination, 9,195,000 warrants, including 5,750,000 Public Warrants and 3,445,000 Private Placement warrants, previously issued by Blue Water, were assumed by the Company. Upon consummation of the Merger, the Company concluded that the Public Warrants are equity classified and the Private Placement Warrants are liability classified in accordance with ASC 815. The Private Placement Warrants are a freestanding financial instrument that requires the Company to transfer equity instruments upon exercise by the warrant holder at a strike price equal to $11.50 per share (the “Private Placement Warrant Liability”). The valuation of the private placement warrant liability was determined with the assistance of an independent valuation firm that used a modified Monte Carlo simulation model at inception and subsequently at each measurement date using the Black-Scholes model. The fair value was determined using Level 3 inputs. The Private Placement Warrants to purchase common stock are remeasured at each reporting and settlement date. Changes in fair value for each reporting period are recognized in other income (expense) in the statements of operations. A change in the assumptions related to the valuation of the Warrant Liability could have a significant impact on the value of the obligation. The following table sets forth a summary of changes in the fair value of the Company’s warrant liability for the three and nine months ended September 30, 2021 (in thousands): Beginning warrant liability balance $ — Private placement warrant liability assumed 14,075 Change in fair value of warrant liability (7,610 ) Balance at September 30, 2021 $ 6,465 Derivative Liability From 2016 through 2020, Old Clarus entered into convertible notes purchase agreements with related parties for a total aggregate borrowing amount of $61.3 million (see Note 7, Debt non-qualified non-qualified	3. Fair Value Measurements The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: December 31, 2020 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 7,205 $ 7,205 $ — $ — Total assets $ 7,205 $ 7,205 $ — $ — Liabilities Warrant liability $ — $ — $ — $ — Derivative liability — — — — Total liabilities $ — $ — $ — $ — December 31, 2019 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 1,628 $ 1,628 $ — $ — Total Assets $ 1,628 $ 1,628 $ — $ — Liabilities Warrant liability $ 551 $ — $ — $ 551 Derivative liability 65,006 — — 65,006 Total liabilities $ 65,557 $ — $ — $ 65,557 During the years ended December 31, 2020 and 2019, there were no transfers between levels. As of December 31, 2020 and 2019, the Company’s cash equivalents consisted of money market funds, classified as Level 1 financial assets, as these assets are valued using quoted market prices in active markets without any valuation adjustment. There were no financial assets valued based on Level 2 inputs. As of December 31, 2019, the Company had Level 3 financial liabilities that were measured at fair value on a recurring basis. The Company’s Warrant Liability and Derivative Liability (defined below) are carried at fair value, determined using Level 3 inputs in the fair value hierarchy as described below. As of December 31, 2020, the Warrant Liability and Derivative Liability were valued at zero. The carrying amounts reported in the accompanying balance sheets for cash, accounts receivable, accounts payable and accrued expenses approximate their fair value based on the short-term nature of these instruments. The carrying value of long-term and short-term debt, taking into consideration debt discounts and related derivative instruments, is estimated to approximate fair value. Warrant Liability In conjunction with a previous loan agreement that was fully paid in 2017, certain lenders were granted warrants, or the Series D Warrants, to purchase a total of 183,438 shares of Series D Preferred Stock at an exercise price of $4.50 per share. The expiration date of the warrants will be the earlier of July 14, 2021 for 122,292 shares and April 9, 2023 for 61,146 shares, or three years from the effective date of a registration statement for an initial public offering of the Company’s stock. No warrants were exercised during the years ended December 31, 2020 and 2019. The warrant is a freestanding financial instrument that requires the Company to transfer equity instruments upon exercise by the warrant holder at a strike price equal to the issuance price of the underlying preferred stock (the “Warrant Liability”). The valuation of the warrant liability was determined with the assistance of an independent valuation firm which utilized the hybrid method, a hybrid valuation between a probability-weighted expected return model (“PWERM”) and an option pricing model (“OPM”). The hybrid method estimates probability-weighted values across multiple scenarios, but uses the OPM to estimate the allocation of value within one or more of those scenarios. Weighting allocations are assigned to the OPM and PWERM methods factoring possible future liquidity events. Specifically, for each exit event date and exit scenario, the OPM method was utilized to estimate the Series D Preferred Stock value per share. The fair value was determined using Level 3 inputs. The warrants to purchase preferred stock are remeasured at each reporting and settlement date. Changes in fair value for each reporting period are recognized in other income (expense) in the statements of operations. A change in the assumptions related to the valuation of the Warrant Liability could have a significant impact on the value of the obligation. The following table sets forth a summary of changes in the fair value of the Company’s warrant liability (in thousands): Balance at December 31, 2018 $ 689 Change in fair value of warrants (138 ) Balance at December 31, 2019 $ 551 Change in fair value of warrants (551 ) Balance at December 31, 2020 $ — As the fair value of Series D Preferred Stock at December 31, 2020 was less than the Series D Preferred Stock issuance price of $4.50, the fair value of the Series D warrants was reduced to zero. Derivative Liability From 2016 through 2020, the Company entered into convertible notes purchase agreements with related parties for a total aggregate borrowing amount of $61.3 million (see Note 7, Debt non-qualified non-qualified The derivative liability is a freestanding financial instrument that requires the Company to transfer equity instruments upon exercise by the noteholders. The derivative liability was initially recorded as a liability at fair value, with a corresponding debt discount, which was amortized to interest expense using the effective interest rate method over the term of the related notes. The valuation of the derivative liability was determined with the assistance of an independent valuation firm utilizing a probability-weighted expected return model (“PWERM”), which estimates the value based on probability-weighted present value of potential future liquidity events, with an allocation of probabilities applied to each scenario. Future liquidity event scenarios for the Convertible Notes as of December 31, 2019 included an acquisition event prior to expected FDA approval, an IPO prior to expected FDA approval, an acquisition event after expected FDA approval and an IPO after expected FDA approval, and only two scenarios as of December 31, 2020 which were an acquisition event after expected FDA approval and an IPO after expected FDA approval. The fair value was determined using Level 3 inputs. The derivative liability is remeasured at each reporting and settlement date. Changes in fair value for each reporting period are recognized in other income (expense) in the statements of operations. A change in the assumptions related to the valuation of the derivative liability could have a significant impact on the value of the obligation. The following table sets forth a summary of changes in the fair value of the Company’s derivative liability (in thousands): Balance at December 31, 2018 $ 50,020 2019 Notes issued 14,861 Change in fair value of derivative 125 Balance at December 31, 2019 $ 65,006 2020 Notes issued 1,334 Change in fair value of derivative (66,340 ) Balance at December 31, 2020 $ — As the fair value of Series D Preferred Stock at December 31, 2020 was less than the Series D Preferred Stock issuance price of $4.50, the fair value of the derivative liability related to the Company’s convertible notes was reduced to zero.

Inventory

Inventory	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Inventory	5. Inventory Inventory consisted of the following as of September 30, 2021 and December 31, 2020 (in thousands): September 30, December 31, 2021 2020 Raw material $ 6,738 $ 4,225 Work-in-process 5,778 — Finished goods 7,865 9,475 Total inventory 20,381 13,700 Inventory reserve (7,901 ) (7,843 ) Total inventory, net of reserve $ 12,480 $ 5,857	4. Inventory Inventory consisted of the following as of December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Raw material $ 4,225 $ 94 Work-in-process — 4,664 Finished goods 1,632 2,203 Total $ 5,857 $ 6,961 As of December 31, 2020, the Company recorded a reserve for inventory obsolescence of $7.8 million, with a corresponding charge to cost of product sales. The charge was estimated based on an analysis of the remaining shelf life of the Company’s inventory at the time that inventory is forecasted to be sold.

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment, net	5. Property and Equipment, net Property and equipment consisted of the following as of December 31, 2020 and 2019 (in thousands): December 31, 2020 2019 Office equipment and computer hardware $ 99 $ 96 Furniture and fixtures 109 51 Total property and equipment 208 147 Less accumulated depreciation (144 ) (126 ) Property and equipment, net $ 64 $ 21 Depreciation expense for the years ended December 31, 2020 and 2019 was approximately $18 thousand and $4 thousand, respectively.

Accrued Expenses

Accrued Expenses	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued Expenses	6. Accrued Expenses Accrued expenses consisted of the following (in thousands): September 30, December 31, 2021 2020 Selling and marketing costs $ 5,905 $ 3,468 Employee compensation and related benefits 1,074 1,090 Professional fees 388 73 Other 6 — Total $ 7,373 $ 4,631	6. Accrued Expenses Accrued expenses consisted of the following (in thousands): December 31, 2020 2019 Selling and marketing costs $ 3,468 $ 698 Employee compensation and related benefits 1,090 569 Other research costs — 61 Professional Fees 73 426 Other — 13 Total $ 4,631 $ 1,767

Debt

Debt	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	7. Debt Convertible Notes From 2016 to 2021, Old Clarus issued several convertible notes (the “Convertible Notes”) pursuant to which Old Clarus borrowed an aggregate of $82.3 million from existing investors and related parties. All Convertible Notes accrued interest at a rate of 8% compounded daily and had a maturity date of March 1, 2025. The Convertible Notes contained various conversion features. The Company recorded the notes at the original issuance price, net of the conversion feature discount. The conversion feature discount was accreted to the face value of the notes over the period from the issuance date until the conversion date, offset against interest expense. At the Effective Time, all principal and accrued interest under Old Clarus’ convertible notes and Old Clarus’ outstanding warrants immediately prior to the Effective Time converted into 8,529,846 shares of the Company’s common stock. As such, there are no Convertible Notes outstanding on September 30, 2021. As of December 31, 2020, the carrying value of the Convertible Notes consisted of (in thousands): December 31, 2020 Principal amount $ 61,300 Accrued and unpaid interest 17,287 Unamortized debt discount (676 ) Total $ 77,911 In March 2021, upon an investor’s decision to not participate in the next round of Convertible Notes, pursuant to the Convertible Notes’ provisions, $3.4 million of the investor’s Convertible Notes converted into 747,451 shares of Series D Preferred Stock and such Series D Preferred Stock issued as a result of this conversion was converted into Old Clarus common stock. At the date of conversion, the outstanding principal and accrued interest on the Convertible Notes were $2.6 million and $0.8 million, respectively. The Company recognized interest expense of $1.5 million during the three months ended September 30, 2021 and 2020, respectively. The Company recognized interest expense of $4.9 million and $4.5 million during the nine months ended September 30, 2021 and 2020, respectively. Senior Secured Notes The carrying value of the Company’s senior secured notes consisted of the following (in thousands): September 30, December 31, 2021 2020 Principal amount $ 43,125 $ 50,000 Accrued and unpaid interest 1,234 1,278 Unamortized debt discount (8,062 ) (9,376 ) Total $ 40,339 $ 41,902 On March 12, 2020, Old Clarus issued and sold senior secured notes to certain lenders not related to In the second quarter of 2021, Old Clarus added two additional notes to the principal senior secured notes balance, the PIK Note (as defined and further described below) and the Indenture Note (as defined and further described below), totaling $8.1 million. In the third quarter of 2021, the Company added one additional note to the principal senior secured notes balance, the Second Indenture Note (as defined and further described below), totaling $3.6 million. As part of the Merger (as further described in Note 1), $10.0 million of the principal on the senior secured notes and certain royalty rights were exchanged for an 1,500,000 shares of the Company’s common stock and converted at a price of $10.20 per share. Further, under a share allocation agreement entered into by Blue Water and Old Clarus on September 1, 2021, as part of the Merger, an additional 405,000 shares of the Company’s common stock were allocated to the senior secured noteholders (which included 270,000 shares reallocated from Old Clarus’s equity holders and 135,000 shares that were transferred from the Sponsor pursuant to the share allocation agreement), and converted at a price of $10.20 per share. Further, an additional $5.0 million of the principal of the senior secured notes balance associated with the Indenture Note and $3.6 million of the principal of the senior secured notes balance associated with the Second Indenture Note, plus related accrued interest, were exchanged for an aggregate 882,318 shares of the Company’s common stock, which converted at a price of $10.00 per share. As a result of the exchange of the principal on the senior secured notes and certain royalty rights for shares of the Company’s common stock, the Company wrote off $18.6 million of principal associated with the senior secured notes, $1.5 million of the remaining unamortized debt discount associated with the senior secured notes, and the full carrying value of $11.5 million associated with royalty rights obligation. The Company recorded a gain of approximately $0.3 million during the period ending September 30, 2021 as a result of the extinguishment, representing the difference between the carrying value of the debt exchanged and the value of the shares converted based on the conversion price. The senior secured notes bear interest at 12.5% and specify semiannual payments on March 1 and September 1 and have a maturity date of March 1, 2025. The first two years provide for interest-only payments with principal payment beginning in 2022. The senior secured notes are governed by an indenture, dated as of March 12, 2020, between Old Clarus and the investors. The interest rate will increase to 14.50% for overdue installments in the event of default. In addition to liquidation preference, the senior secured notes contain a lien on all assets of Old Clarus. Future principal payments of the senior secured notes are as follows (in thousands): Years ended December 31, Amount 2021 (remaining 3 months) $ — 2022 6,000 2023 15,125 2024 14,000 2025 8,000 Total $ 43,125 The senior secured notes had a detachable royalty feature under which the lenders were to receive a royalty of 0.56% to 1.67% on net sales beginning in 2021, with the royalty obligation continuing until the lenders receive total royalty payments of approximately $24.2 million. The value assigned to royalty rights was recorded as a debt discount to the Notes and is amortized to interest expense over the life of the notes. For the three months ended September 30, 2021 and 2020, the Company recorded $0.7 million and $0.6 million, respectively, of interest expense associated with the royalty rights. For the nine months ended September 30, 2021 and 2020 the Company recorded $2.2 million and $1.4 million, respectively, of interest expense associated with the royalty rights. The royalty obligation had a fair value of $7.9 million at issuance in March of 2020. Pursuant to the Merger Agreement and conversion terms, no royalty obligation exists as of September 30, 2021. During the three months ended September 30, 2021 and 2020, the Company recorded $2.6 million and $2.1 million, respectively in interest expense on the senior secured notes, of which $0.7 million and $0.7 million, respectively, was non-cash non-cash Pursuant to the indenture governing the senior secured notes, Old Clarus agreed to maintain cash and cash equivalents in an amount of not less than $10.0 million, calculated as of the last day of each calendar month, commencing on March 31, 2020. As of December 31, 2020, Old Clarus’ cash and cash equivalents were less than $10.0 million, resulting in a default under the indenture and the negotiation of a forbearance agreement, as noted below. In connection with the Merger, the indenture was amended to require the Company to maintain a balance of not less than $8.0 million in cash and cash equivalents, calculated as of the last day of each calendar month. The Company has classified the full carrying value of $40.3 million related to the senior secured notes as a current liability within the September 30, 2021 balance sheet as, if the Company is unable to obtain funding or generate operating cash flow, the Company does not expect that it will be in compliance with the covenants under the senior secured notes within one year of the balance sheet date. Refer to Note 1 for further disclosure related to the Company’s assessment of the ability to operate as a going concern as of September 30, 2021. Forbearance Agreement On March 17, 2021, Old Clarus entered into a forbearance agreement with noteholders in relation to the senior secured notes. Old Clarus was unable to and did not pay interest of $3.1 million due on March 1, 2021. As of March 31, 2021, Old Clarus entered into default on its senior secured notes, and in accordance with the terms of the senior secured notes, the interest increased to 14.5%. Under the forbearance agreement, in exchange for the investors’ agreement not to exercise their rights to retrieve the funds owed, Old Clarus was required to maintain cash and cash equivalents of at least $2.5 million amongst other financial budgeting and reporting requirements until consummation of the Business Combination. Under the forbearance agreement, the forbearance period would not be terminated provided that Old Clarus, amongst other things, executed the Merger Agreement and provided financial reporting requirements by April 27, 2021. Forbearance Extension In August 2021, Old Clarus entered into forbearance extensions with the noteholders in relation to the senior secured notes. The latest forbearance extension, entered into on August 26, 2021, extended the forbearance period through September 9, 2021, the Closing Date of the Merger. On September 28, 2021, the Company entered into a supplemental indenture with the noteholders in relation to the senior secured notes. The supplemental indenture extended the due date of the $3.9 million interest payment due September 1, 2021 to March 1, 2022, and further accrues interest on the past interest due amount at a rate of 18.5% per annum beginning on September 1, 2021 until paid. PIK Note In May 2021, Old Clarus entered into a payment-in-kind, Indenture Note In June 2021, Old Clarus entered into the Indenture Note (the “Indenture Note”), pursuant to which it borrowed an aggregate of $5.0 million from senior secured noteholders, to be included in the principal senior secured notes balance. The Indenture Note accrues interest at a rate of 14.5%, compounded daily, and was repaid with the Company’s common stock upon the closing of the Merger. Second Indenture Note In July 2021, Old Clarus entered into an additional note purchase agreement (the “Second Indenture Note”) pursuant to which it borrowed an aggregate of $3.6 million from senior secured noteholders. The outstanding balance under the Second Indenture Note accrues interest at a rate of 14.5%, compounded daily, and was repaid with the Company’s common stock upon the closing of the Merger. PPP Loan In March of 2020, the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was enacted to, among other provisions, provide emergency assistance for individuals, families and businesses affected by the COVID-19 In April of 2020, Old Clarus received an unsecured loan of $0.5 million from the SBA. After considering further guidance issued by the SBA, Old Clarus elected to repay the loan in full in May of 2020 with no interest due under safe harbor provisions of the CARES Act.	7. Debt Convertible Notes From 2016 to 2020, the Company issued several convertible notes (the “Convertible Notes”) pursuant to which the Company borrowed an aggregate of $61.3 million from existing investors and related parties. All Convertible Notes accrue interest at a rate of 8% compounded daily and have a maturity date of March 1, 2025. The Company had the following convertible notes outstanding as of December 31, 2020 (in thousands): Issuance Year Aggregate 2016 $ 18,000 2017 14,000 2018 9,300 2019 18,389 2020 1,611 Total $ 61,300 The Convertible Notes contain various conversion features. Upon the occurrence of a qualified financing, the Convertible Notes plus accrued interest mandatorily converts, to shares issued in the qualified financing, as defined in the notes, at a 20% discount, or into shares of Series D Preferred Stock at the Series D Price of $4.50 per share. Upon the occurrence of a non-qualified non-qualified The Company determined that the acquisition premium and the qualified and non-qualified Fair Value Measurements During the year ended December 31, 2020, pursuant to the executed amendment of the Convertible Notes, the Company and certain lenders agreed to extend or further extend the maturity dates of the Convertible Notes to March 1, 2025. The amendment only modified the maturity date, no other terms, and accordingly was deemed administrative in nature as it was not intended to change any of the economic terms between parties. As such the extension of the maturity dates was deemed to be a modification of the Convertible Notes and modification accounting was applied. The Company calculated the remaining debt discount for each of the Convertible Notes and adjusted the effective interest rate to amortize the remaining debt discount over the adjusted remaining life of the Convertible Notes. The carrying value of the Company’s Convertible Notes is as follows (in thousands): December 31, 2020 2019 Principal amount $ 61,300 $ 59,689 Accrued and unpaid interest 17,287 11,230 Unamortized debt discount (676 ) — Total $ 77,911 $ 70,919 The Company recognized interest expense of $6.1 million and $4.5 million during the years ended December 31, 2020 and 2019, respectively. Senior Secured Notes The carrying value of the Company’s senior secured notes is as follows (in thousands): December 31, Principal amount $ 50,000 Accrued and unpaid interest 1,278 Unamortized debt discount (9,376 ) Total $ 41,902 On March 12, 2020, the Company issued and sold senior secured notes to certain lenders not related to the Company. The aggregate principal amount of the senior secured notes was $50.0 million and the Company received $42.7 million in net proceeds after deducting transaction expenses of $4.4 million and prepaid interest of $2.9 million. The senior secured notes bear interest at 12.5% and specify semiannual payments on March 1 and September 1 and have a maturity date of March 1, 2025. The first two years provide for interest-only payments and the final three years amortize the principal balance at $15.0 million, $15.0 million and $20.0 million, respectively. The senior secured notes are governed by an indenture, dated as of March 12, 2020, between the Company and the investors. The interest rate will increase to 14.50% for overdue installments in the event of default. In addition to liquidation preference, the senior secured notes contain a lien on all assets of the Company. Future principal payments of the senior secured notes are as follows (in thousands): Years ending December 31, Amount 2021 $ — 2022 7,500 2023 15,000 2024 17,500 2025 10,000 Total $ 50,000 The senior secured notes also have a detachable royalty feature under which the lenders receive a royalty of 0.56% to 1.67% on net sales beginning in 2021, with the royalty obligation continuing until the lenders receive total royalty payments of approximately $24.2 million. The value assigned to royalty rights is recorded as a debt discount to the Notes and is amortized to interest expense over the life of the notes. The royalty obligation had a fair value of $7.9 million at issuance in March of 2020. The lenders have a security interest in the assets and intellectual property of the Company. Since the royalty rights are tied to Clarus’ net sales of JATENZO, such royalty rights are not subject to treatment as a derivative instrument and thus do not need to be periodically measured and marked to market. Proceeds were used to finance the commercial launch of JATENZO. Refer to the section below for the accounting treatment of the royalty obligation. In connection with the senior secured notes, the Company entered into an indenture stating that the Company would maintain cash and cash equivalents in the amount of at least $10.0 million as of the last day of each calendar month, commencing on March 31, 2020. As of December 31, 2020, the Company was unable to maintain cash and cash equivalents of $10.0 million, and such breach of the indenture resulted in a default and the negotiation of a forbearance agreement noted below. Forbearance Agreement On March 17, 2021, the Company entered into a forbearance agreement with noteholders in relation to the senior secured notes. The Company was unable to and did not pay interest of $3.1 million due on March 1, 2021. If the Company is unable to secure the funds to repay its debt as of March 31, 2021, all investors have the right to exercise all remedies available under the indenture to receive the funds due. Under the forbearance agreement, in exchange for the investors’ agreement not to exercise their rights to retrieve the funds owed, the Company was required to maintain cash and cash equivalents of at least $2.5 million amongst other financial budgeting and reporting requirements until consummation of the Business Combination. Under the forbearance agreement, the forbearance period would automatically terminate if certain conditions, including the execution of the merger agreement, did not occur on or prior to April 15, 2021 (see Note 15, Subsequent Events On April 14, 2021, the Company entered into a written consent to update the terms of its forbearance agreement. Per the written consent, the forbearance period would not be terminated on April 15, 2021, provided that the Company, amongst other things, executed the merger agreement and provided financial reporting requirements by April 27, 2021. Royalty Obligation The Company periodically assesses the estimated royalty payments related to the senior secured notes to the lender and to the extent such payments are greater or less than its initial estimates or the timing of such payments is materially different than its original estimates, the Company will prospectively adjust the accretion of interest on the royalty obligation. There are a number of factors that could materially affect the amount and the timing of royalty payments, most of which are not within the Company’s control. Such factors include, but are not limited to, the rate of JATENZO prescriptions, the number of doses administered, the introduction of competing products, manufacturing or other delays, patent protection, adverse events that result in governmental health authority-imposed restrictions on the use of the drug products, and sales never achieving forecasted numbers, which would result in reduced royalty payments and reduced non-cash The Company records estimated royalties due for the current period in accrued other expenses until the payment is received from the customer, at which time the Company then remits payment to the lenders. In order to determine the accretion of the royalty obligation, the Company is required to estimate the total amount of future royalty payments to be received and submitted to the lenders. The sum of these amounts less the proceeds the Company received will be recorded as interest expense over the life of the royalty obligation. As of December 31, 2020, the Company’s estimate of its total interest expense resulted in an annual effective interest rate of approximately 32.3%. The following table shows the activity of the royalty obligation since the transaction inception through December 31, 2020: December 31, Value assigned to royalty obligation at inception $ 7,211 Non-cash 2,051 Royalty obligation — ending balance $ 9,262 PPP Loan In March of 2020, the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was enacted to, among other provisions, provide emergency assistance for individuals, families and businesses affected by the COVID-19 In April of 2020, the Company received an unsecured loan of $0.5 million from the SBA. After considering further guidance issued by SBA, the Company elected to repay the loan in full in May of 2020 with no interest due under safe harbor provisions of the CARES Act.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2021
Stockholders Equity Note [Line Items]
Stockholders' Equity	8. Stockholders’ Equity (Deficit) The condensed consolidated statement of stockholders’ equity (deficit) has been retroactively adjusted for all periods presented to reflect the Business Combination and reverse recapitalization as defined in Note 3, Business Combination Preferred Stock Pursuant to the terms of the Amended and Restated Certificate of Incorporation dated September 9,2021, the Company authorized 10,000,000 shares of preferred stock with a par value of $0.0001. The Company’s Board of Directors has the authority, without further action by the stockholders, to issue such shares of preferred stock in one or more series, to establish from time to time the number of share to be included in each such series, and to fix the designations, powers, voting, and other rights, preferences and privileges of the shares. There were no issued and outstanding shares of preferred stock as of September 30, 2021. In connection with the closing of the Business Combination, all previously issued and outstanding shares of Series A Preferred Stock, Series B Preferred Stock, and Series C Preferred Stock were cancelled and extinguished. Further, all previously issued and outstanding Series D Preferred Stock was cancelled and exchanged for 4,901,564 shares of the Company’s common stock. Common Stock Pursuant to the terms of the Amended and Restated Certificate of Incorporation, the Company authorized 125,000,000 shares of common stock with a par value of $0.0001. Immediately following the closing of the Business Combination and as of September 30, 2021, there were 21,725,817 shares of common stock issued and outstanding. As discussed in Note 3, Business Combinations, Voting Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Dividends Common stockholders are entitled to receive dividends, as may be declared by the board of directors. No dividends have been declared to date.

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2020
Redeemable Convertible Preferred Stock [Abstract]
Redeemable Convertible Preferred Stock	8. Redeemable Convertible Preferred Stock There were no shares of redeemable convertible preferred stock issued during the years ended December 31, 2020 and December 31, 2019 As of December 31, 2020, and 2019, preferred stock consisted of the following (in thousands, except for share data): December 31, 2020 Preferred Preferred Carrying Liquidation Common Series A Preferred Stock 2,500,000 2,500,000 $ 9,170 $ 9,170 2,500,000 Series B Preferred Stock 5,066,637 5,066,637 15,118 15,118 5,066,637 Series C Preferred Stock 9,438,744 9,438,744 20,057 20,057 9,438,744 Series D Preferred Stock 36,335,255 19,751,117 153,850 153,850 19,751,117 Total 53,340,636 36,756,498 $ 198,195 $ 198,195 36,756,498 December 31, 2019 Preferred Preferred Carrying Liquidation Common Series A Preferred Stock 2,500,000 2,500,000 $ 8,491 $ 8,491 2,500,000 Series B Preferred Stock 5,066,637 5,066,637 13,998 13,998 5,066,637 Series C Preferred Stock 9,438,744 9,438,744 18,571 18,571 9,438,744 Series D Preferred Stock 36,335,255 19,751,117 142,453 142,453 19,751,117 Total 53,340,636 36,756,498 $ 183,513 $ 183,513 36,756,498 The following is a summary of the rights and preferences of Series A Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, and Series D Preferred Stock (collectively, “Preferred Stock”) are as follows: Conversion share-for-share share-for-share Dividends Liquidation Preference Redemption Voting Rights as-converted of the Preferred Stock. The holders of Series C Preferred Stock are entitled to elect three directors to the Company’s board of directors and the holders of Series D Preferred Stock are entitled to elect one director to the Company’s board of directors. Certain actions, such as mergers, acquisition, liquidation, dissolution, wind up of business, and deemed liquidation events, must be approved by the holders of at least 65% of outstanding shares of Series D Preferred Stock.

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2020
Common Stock [Abstract]
Common Stock	9. Common Stock The Company was authorized to issue up to 56,593,539 shares of common stock with a $0.001 par value per share as of December 31, 2020. The voting, dividend and liquidation rights of the holders of the Company’s common stock are subject to and qualified by the rights, powers and preferences of the holders of the preferred stock as set forth above. The holders of common stock are entitled to one vote for each share of common stock. Subject to the payment in full of all preferential dividends to which the holders of the Preferred Stock are entitled, the holders of common stock shall be entitled to receive dividends out of funds legally available. In the event of any voluntary or involuntary liquidation, dissolution, or winding up of the Company, after the payment or provision for payment of all debts and liabilities of the Company and all preferential amounts to which the holders of Preferred Stock are entitled with respect to the distribution of assets in liquidation, the holders of common stock shall be entitled to share ratably in the remaining assets of the Company available for distribution. As of December 31, 2020, and 2019, the Company has reserved the following shares of common stock for the potential conversion of outstanding preferred stock and exercise of stock options: December 31, 2020 2019 Preferred stock, as converted 36,756,498 36,756,498 Options to purchase common stock 3,814,659 2,307,640 Series D warrants 183,438 183,438 Remaining shares reserved for future issuance 1,350,481 3,156,710 Total 42,105,076 42,404,286

Stock Based Compensation

Stock Based Compensation	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation 2004 Old Clarus Stock Incentive Plan Effective February 13, 2004, Old Clarus adopted the Clarus Therapeutics 2004 Stock Incentive Plan (the “2004 Plan”). The 2004 Plan was amended on January 28, 2011 to increase the number of shares of Old Clarus’s common stock reserved for issuance to employees, directors, and consultants to 1,529,936 shares. Options granted under the 2004 Plan could have been incentive stock options or non-statutory 10 -year At the Effective Time, the 2004 Plan and all options issued and outstanding, whether vested or unvested, were cancelled and extinguished. 2014 Old Clarus Stock Option and Incentive Plan Effective February 13, 2014, Old Clarus adopted the Clarus Therapeutics 2014 Stock Option and Incentive Plan (the “2014 Plan”) and reserved 1,000,000 shares of Old Clarus common stock for the issuance of awards under the 2014 Plan. The 2014 Plan permitted Old Clarus to make grants of incentive stock options, non-qualified non-employee 10-year At the Effective Time, the 2014 Plan was terminated and all options issued and outstanding, whether vested or unvested, were cancelled and extinguished. Clarus Therapeutics Holdings Inc. 2021 Stock Option and Equity Incentive Plan On August 27, 2021 the Company’s stockholders approved the Clarus Therapeutics Holdings Inc. 2021 Stock Option and Equity Incentive Plan (the “2021 Plan”). The 2021 Plan provides for the Company to make equity and equity-based incentive awards to officers, employees, directors and consultants. Pursuant to the 2021 Plan, an initial 3,475,000 shares of the Company’s common stock were reserved for issuance (the “Initial Limit”). The 2021 Plan provides that the shares reserved and available for issuance under the 2021 Plan will automatically increase each January 1, beginning on January 1, 2022, by 4% of the outstanding number of shares of common stock on the immediately preceding December 31, or such lesser amount as determined by the plan administrator (the “Annual Increase”). As of September 30, 2021 no awards have been granted and no shares were issued under the 2021 Plan. Clarus Therapeutics Holdings, Inc. Employee Stock Purchase Plan On August 12, 2021 the Company’s stockholders approved the Clarus Therapeutics Holdings Inc. Employee Stock Purchase Plan (the “ESPP”). An aggregate of 347,500 shares were reserved and available for issuance under the 2021 ESPP. The 2021 ESPP provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning on January 1, 2022, by the lesser of 347,500 shares of the Company’s common stock, 1.0% of the outstanding number of shares of the Company’s common stock on the immediately preceding December 31, or such lesser amount as determined by the ESPP administrator. As of September 30, 2021 the Company had not issued any shares under the ESPP. Stock-Based Compensation Expense Stock-based compensation expense is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Selling and marketing $ 6 $ — $ 15 $ — Research and development 19 15 52 54 General and administrative 182 75 491 180 Total stock-based compensation expense $ 207 $ 90 $ 559 $ 234 As of September 30, 2021, there was no unrecognized stock-based compensation expense related to unvested stock options as no options have been granted under the 2021 Plan. At the Effective Time, the 2004 Plan and 2014 Plan were terminated and all options issued and outstanding, whether vested or unvested, were cancelled and extinguished. As a result, the Company recognized approximately $0.2 million of previously unrecognized stock-based compensation expense related to unvested stock options under the 2004 Plan and 2014 Plan during the period ended September 30, 2021.	10. Stock-Based Compensation 2004 Stock Incentive Plan Effective February 13, 2004, the Company adopted the Clarus Therapeutics 2004 Stock Incentive Plan (the “2004 Plan”). The 2004 Plan was amended on January 28, 2011 to increase the number of shares of the Company’s common stock reserved for issuance to employees, directors, and consultants to 1,529,936 shares. Options granted under the 2004 Plan may be incentive stock options or non-statutory 10-year 2014 Stock Option and Incentive Plan Effective February 13, 2014, the Company adopted the Clarus Therapeutics 2014 Stock Option and Incentive Plan (the “2014 Plan”) and reserved 1,000,000 shares of Common Stock for the issuance of awards under the 2014 Plan. The 2014 Plan permits the Company to make grants of incentive stock options, non-qualified non-employee 10-year Stock Options The following table summarizes stock option activity under the Plans: Number of Weighted Weighted Aggregate Outstanding as of December 31, 2019 2,307,640 $ 1.70 5.1 $ — Granted 1,806,229 2.69 Exercised — — Cancelled (142,500 ) 1.49 Forfeited (156,710 ) 1.98 Outstanding as of December 31, 2020 3,814,659 $ 2.17 6.8 $ — Options vested and exercisable as of December 31, 2020 2,320,686 $ 1.86 6.9 $ — The weighted average grant-date fair value of stock options granted in 2020 and 2019 was $1.26 per share and $1.59 per share, respectively. The total fair value of stock options vested during the years ended December 31, 2020 and 2019 was $0.8 million and $0.4 million, respectively. The fair value was estimated on the date of grant using the Black-Scholes option-pricing model, with the following weighted-average assumptions: Years Ended 2020 2019 Expected volatility 59.66 % 58.13 % Weighted-average risk-free interest rate 1.59 % 2.58 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 4.00 4.00 Stock-Based Compensation Expense Stock-based compensation expense is as follows (in thousands): Years Ended 2020 2019 Selling and marketing $ 183 $ — Research and development 189 108 General and administrative 453 251 Total stock-based compensation expense $ 825 $ 359 As of December 31, 2020, there was $0.6 million of unrecognized stock-based compensation expense related to unvested stock options, which is being recognized over a period of 1.14 years.​​​​​​​

Income Taxes

Income Taxes	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Income Taxes	10. Income Taxes The Company did not record a federal or state or income tax provision or benefit for the nine months ended September 30, 2021 or 2020 due to the expected loss before income taxes to be incurred, as well as the Company’s continued maintenance of a full valuation allowance against its net deferred tax assets. Under Internal Revenue Code Section 382, if a corporation undergoes an “ownership change,” the corporation’s ability to use its pre-change pre-change	11. Income Taxes No provision for federal or state income taxes was recorded during the years ended December 31, 2020 and 2019, as the Company incurred operating losses and maintains a full valuation allowance against its net deferred tax assets. The reported amount of income tax benefit for the years ended December 31, 2020 and 2019 differs from the amount that would result from applying domestic federal statutory rates to pretax losses primarily because of changes in the valuation allowance, state taxes, and the generation of research and development credits. A reconciliation of the Company’s statutory income tax rate to the Company’s effective income tax rate is as follows (in thousands): Year Ended December 31, 2020 2019 Income at U.S. statutory rate $ 912 21.00 % $ (8,746 ) 21.00 % State taxes, net of federal benefit (1,583 ) -36.45 % (1,171 ) 2.81 % Change in fair value (14,047 ) -323.39 % — 0.00 % Interest expense 1,410 32.46 % 5,009 -12.03 % Stock compensation 127 2.93 % 1,139 -2.73 % Permanent differences 6 0.13 % 3 -0.01 % Valuation allowance 13,175 303.32 % 3,561 -8.55 % Other — 0.00 % 205 -0.49 % $ — 0.00 % $ — 0.00 % The net deferred income tax asset balance related to the following (in thousands): Year Ended 2020 2019 Deferred tax assets Stock compensation $ 64 $ 12 Accruals and other 4,151 1,060 Debt discount 483 — Royalty liability 2,272 — Net operating loss carryforwards 51,918 44,641 Tax credits 6,774 6,774 Total deferred tax assets 65,662 52,487 Less: valuation allowance (65,662 ) (52,487 ) Deferred tax assets, net $ — $ — At December 31, 2020, the Company had approximately $189.2 million and $169.1 million of federal and state net operating loss (“NOL”) carryforwards, respectively. Approximately $134.9 million of the federal NOL and $124.1 million of the state NOL was generated prior to the 2018 tax year. As a result, these net operating loss carryforwards will expire, if not utilized, between 2021 and 2037 for federal and state income tax purposes. As a result of the Tax Cuts and Jobs Act, federal NOLs generated in tax years ending after December 31, 2017 are limited to a deduction of 80% of the taxpayer’s taxable income. Furthermore, the post 2017 NOLs are subject to an indefinite carryforward period; therefore, $54.4 million of federal NOL generated after 2017 may be carried forward indefinitely. As it pertains to the approximately $45.0 million of state NOLs generated after 2017, not all states have conformed to the Act; therefore, the NOL expiration will vary based on the state. The Company also has federal tax credits of $6.7 million, which begin to expire in 2024 and state tax credits of $0.1 million which begin to expire in 2021. Future realization of the tax benefits of existing temporary differences and net operating loss carryforwards ultimately depends on the existence of sufficient taxable income within the carryforward period. As of December 31, 2020 and 2019, the Company performed an evaluation to determine whether a valuation allowance was needed. The Company considered all available evidence, both positive and negative, which included the results of operations for the current and preceding years. The Company determined that it was not possible to reasonably quantify future taxable income and determined that it is more likely than not that all of the deferred tax assets will not be realized. Accordingly, the Company maintained a full valuation allowance as of December 31, 2020 and 2019. The Company’s valuation allowance for the year ended December 31, 2020 and 2019 is as follows (in thousands): Year Ended 2020 2019 Valuation allowance at beginning of year $ 52,487 $ 48,926 Increases recorded to income tax provision 13,175 3,561 Valuation allowance at the end of year $ 65,662 $ 52,487 Under Internal Revenue Code Section 382, if a corporation undergoes an “ownership change,” the corporation’s ability to use its pre-change pre-change The calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations for both federal taxes and the many states in which we operate or do business in. ASC 740 states that a tax benefit from an uncertain tax position may be recognized when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, on the basis of the technical merits. The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. The earliest tax years that remain subject to examination by jurisdiction is 2017 for both federal and state. However, to the extent the Company utilizes net operating losses from years prior to 2017, the statute remains open to the extent of the net operating losses or other credits are utilized. The resolution of tax matters is not expected to have a material effect on the Company’s financial statements.

License Agreements

License Agreements	9 Months Ended
	Sep. 30, 2021
License Agreements Disclosure [Abstract]
License Agreements	11. License Agreements Agreement with HavaH In May 2021, Old Clarus entered into a license agreement (the “HavaH Agreement”) with HavaH Therapeutics, or HavaH, an Australia-based biopharmaceutical company developing androgen therapies for inflammatory breast disease and certain forms of breast cancer. Under the HavaH Agreement, the Company will acquire the development and commercialization rights for HavaH T+Ai ™ CLAR-121. Under the terms of the licensing agreement, HavaH may be eligible for up to $10.8 million in potential development and regulatory milestone payments. Additionally, HavaH would be eligible for royalty payments and up to $30.0 million in potential commercial milestones. Such royalty payments will be based on total aggregate annual net sales of CLAR-121 CLAR-121 To date, pursuant to the HavaH Agreement, the Company has made cash payments of $0.5 million consisting of the upfront payment. Agreement with The Royal Institution for the Advancement of Learning/McGill University In September 2021, the Company entered into a license agreement (the “McGill Agreement”) with The Royal Institution for the Advancement of Learning/McGill University, or McGill, a Canadian University. Under the agreement, the Company will develop and commercialize McGill’s proprietary technology designed to treat conditions associated with CoQ10 deficiencies in humans. Under the terms of the licensing agreement, McGill may be eligible for up to $10.5 million in potential development and regulatory milestone payments. Additionally, McGill would be eligible for royalty payments and up to $15.0 million in potential commercial milestones. Such royalty payments will be based on total aggregate annual net sales of any licensed products that are covered by the licensed patents in the territory, at a low single digit percentage rate. To date, pursuant to the McGill Agreement, the Company has made cash payments of $0.4 million consisting of the upfront payment.

Commitments & Contingencies

Commitments & Contingencies	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Commitments And Contingencies [Line Items]
Commitments & Contingencies	12. Commitments and Contingencies Lease Commitments The Company leases office space in Northbrook, Illinois and Murfreesboro, Tennessee under non-cancelable A summary of the Company’s future minimum lease payments required under non-cancellable Years ended December 31, Amount 2021 (remaining 3 months) $ 24 2022 16 2023 — 2024 — 2025 — Total $ 40 Purchase Obligation In July of 2009, Old Clarus entered into a commercial manufacturing agreement, as amended, with Catalent Pharma Solutions, LLC (the “Catalent Agreement”). Pursuant to the terms of the Catalent Agreement, the Company must make minimum annual purchases of JATENZO equal to 7.0 million softgels, through the initial term, or March 2025. Any shortfall between the minimum annual purchase quantities and actual purchases will be multiplied by a unit price, as defined in the Catalent Agreement, and paid to Catalent within 30 days of any year-end two-year Old Clarus entered into a product supply agreement with Pharmacia & Upjohn Company LLC, or Pfizer (the “Pfizer Agreement”), effective January 1, 2021. Pursuant to the terms of the Pfizer Agreement, the Company must make minimum annual purchases of T-undecanoate equal to approximately $1.8 million per year, through the initial term, or January 2024. If there is a shortfall between the minimum annual purchase quantities and actual purchases, the difference between the minimum annual purchase amount and actual purchases will be paid to Pfizer by the Company. There were no purchases under the Pfizer Agreement during the three and nine months ended September 30, 2021. Legal Proceedings From time to time, in the ordinary course of business, the Company is subject to litigation and regulatory examinations as well as information gathering requests, inquiries and investigations. On April 2, 2019, an action for patent infringement was filed against Old Clarus by Lipocine in the U.S. District Court for the District of Delaware. The lawsuit (Civil Action No. 19-cv-622, pre-judgment Old Clarus asserted defenses of noninfringement and invalidity under 35 U.S.C. §§ 103 and 112, and asserted counterclaims of inequitable conduct, patent misuse and exceptional case. Old Clarus’s motion for summary judgment of invalidity under Section 112 was argued on January 15, 2021, and was granted on May 25, 2021, the decision finding all asserted claims invalid for failure to satisfy the written description requirement. On June 15, 2021, Old Clarus requested the Court to schedule a bench trial on Old Clarus’s counterclaims of inequitable conduct, patent misuse, and exceptional case at the earliest practicable date, pursuant to the Court’s invitation to make such a request. In July 2021, Old Clarus and Lipocine entered into a settlement agreement that settled all claims between the parties, including the interference matter (described above) and the pending Old Clarus counterclaims against Lipocine, and provides for a payment by Lipocine to Old Clarus of a $4.0 million settlement fee payable as follows: $2.5 million upfront, $1.0 million within 12 months, and the remainder within two years. The Company is recognizing the payments in income as they are received. The Company received payment of $2.5 million of the $4.0 million in July 2021, which is recorded within the litigation settlement line in other income and expense on the statement of operations. Pursuant to the settlement agreement, a joint stipulation for dismissal was filed, and was so ordered by the Court on July 15, 2021, thereby terminating the district court action. Moreover, and as part of this settlement, Lipocine filed a request for entry of an adverse judgment in Interference No. 106,128 on July 16, 2021. Judgment against Lipocine in Interference No. 106,128 was entered by the U.S. Patent and Trademark Office’s Patent Trial and Appeal Board (PTAB) on July 26, 2021. The Company believes that its ’178 application will proceed to issuance following what it believes will be entry of a decision adverse to Lipocine by the PTAB.	12. Commitments and Contingencies Lease Commitments The Company leases office space in Northbrook, Illinois and Murfreesboro, Tennessee under non-cancelable A summary of the Company’s future minimum lease payments required under non-cancellable Years ending December 31, Amount 2021 $ 95 2022 16 2023 — 2024 — 2025 — Total $ 111 Purchase Obligation In July of 2009, the Company entered into a commercial manufacturing agreement, as amended, with Catalent Pharma Solutions, LLC (the “Catalent Agreement”). Pursuant to the terms of the Catalent Agreement, the Company must make minimum annual purchases of JATENZO equal to 7.0 million softgels, through the initial term, or March 2025. Any shortfall between the minimum annual purchase quantities and actual purchases will be multiplied by a unit price, as defined in the Catalent Agreement, and paid to Catalent within 30 days of any year-end two-year The Company entered into a product supply agreement with Pharmacia & Upjohn Company LLC, or Pfizer (the “Pfizer Agreement”), effective January 1, 2021. Pursuant to the terms of the Pfizer Agreement, the Company must make minimum annual purchases of testosterone undecanoate equal to 2,000 kilograms per year, through the initial term, or January 2024. If there is a shortfall between the minimum annual purchase quantities and actual purchases, the difference between the minimum annual purchase amount and actual purchases will be paid to Pfizer by the Company. Purchases under the Pfizer Agreement are expected to be approximately $1.8 million per year, over the life of the contract. Legal Proceedings From time to time, in the ordinary course of business, the Company is subject to litigation and regulatory examinations as well as information gathering requests, inquiries and investigations. On April 2, 2019, an action for patent infringement was filed against the Company by Lipocine Inc. (“Lipocine”) in the U.S. District Court for the District of Delaware. The lawsuit (Civil Action No. 19-622) pre-judgment Clarus has asserted defenses of noninfringement, invalidity under 35 U.S.C. §§ 103 and 112, as well as inequitable conduct. The Company’s motion for summary judgment of invalidity under Section 112 was argued in January 2021 and is awaiting decision. A hearing has been scheduled before the presiding judge on May 14, 2021 to address questions he has that are pertinent to the summary judgement of motion. The lawsuit is otherwise ready for trial, but no trial date has been set due to court delays arising from the COVID-19 On January 4, 2021, an interference (No. 106,128) was declared by the U.S. Patent and Trademark Office between our U.S. Patent Application No. 16/656,178 and Lipocine’s U.S. Patent Application No. 16/818,779. This proceeding (Interference No. 106,128 (DK)) is currently pending. The claims at issue in the interference cover uses of JATENZO and TLANDO. The involved Lipocine patent application, however, contains claims the Company believes cover the use of TLANDO and not JATENZO. The Company believes that it would not need a license from Lipocine, nor that it would be liable for any damages, based solely on the outcome of the pending interference. There is also risk that other interference proceedings could be declared that involve Lipocine patent applications and/or patents and claims that cover JATENZO interference. And while two interferences were previously decided against the Company, Lipocine has not tried to assert patent claims issued to it as a result of prevailing in those interferences against the Company, and Clarus believes these claims do not cover JATENZO. In the event the Company’s beliefs turn out to be incorrect, or future declared interferences involving claims that cover JATENZO are not resolved in its favor, Clarus may need to obtain a license from Lipocine. Such a license may not be available or may be available only on terms not favorable to the Company. This could also have a material adverse effect on the Company.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	13. Net Income (Loss) Per Share As a result of the Merger, the shares and loss per share related to Old Clarus’s outstanding convertible preferred stock and common stock prior to the Merger have been retroactively restated to reflect the actual shares for which the Series D preferred stock converted into as a result of the conversion terms in the Merger Agreement. Basic and diluted earnings (loss) per share attributable to common stockholders are calculated as follows:​​​​​​​ Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Numerator: Net loss (income) $ (2,769 ) $ 5,406 $ (36,315 ) $ 4,067 Earnings attributable to Old Clarus participating warrants (1) — (10 ) — (8 ) Gain on extinguishment of convertible notes (2) 412 — 412 — Net (loss) income attributable to common stockholders, basic (2,357 ) 5,396 (35,903 ) 4,059 Effect of convertible notes (3) — (19,139 ) — (48,338 ) Net loss attributable to common stockholders, diluted $ (2,357 ) $ (13,743 ) $ (35,903 ) $ (44,279 ) Denominator: Weighted-average common shares attributable to common stockholders, basic 9,153,848 4,901,564 6,318,992 4,901,564 Effect of convertible notes (4) — 16,927,006 — 16,927,006 Weighted average number of common shares - diluted 9,153,848 21,828,570 6,318,992 21,828,570 Net loss per common share attributable to common stockholders, basic $ (0.26 ) $ 1.10 $ (5.68 ) $ 0.83 Effect of convertible notes — (1.73 ) — (2.86 ) Net loss per common share attributable to common stockholders, diluted $ (0.26 ) $ (0.63 ) $ (5.68 ) $ (2.03 ) (1) The loss attributable to Old Clarus participating warrants relates to the total earnings attributable to the 9,246 Old Clarus participating warrants using the two-class (2) The gain on extinguishment of convertible notes relates to the difference between the carrying value of the convertible notes upon conversion to shares and the fair value of the shares exchanged which requires adjustment to the numerator when calculating basic EPS. (3) The effect of the convertible notes on the numerator for the three and nine months ended September 30, 2020 relates to the impact that the convertible notes had on net income during the period, and are removed from net income when calculating net income (loss) attributable to common stockholders diluted using the if-converted (4) The effect of convertible notes on the denominator for the three and nine months ended September 30, 2020 was calculated based on the carrying value of the convertible notes balance at September 30, 2020, converted at the series D price of $4.50 per share and are added back to the denominator when calculating diluted EPS using the if-converted The Company excluded the following shares from the computation of diluted net loss per share attributable to common stockholders as of September 30, 2021 and 2020 because including them would have had an anti-dilutive effect: Three Months September 30, Nine Months September 30, 2021 2020 2021 2020 Convertible notes — — — — Old Clarus Warrants 9,246 — 9,246 — The convertible notes including interest for redeemable convertible preferred stock, which as of September 30, 2020 would be convertible into 16,927,006 shares common stock using the as-if As of the three months and nine months ended September 30, 2021, the Company’s potentially dilutive securities, which include the Old Clarus Series D warrants to purchase common stock, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is not impacted by these securities.	13. Net Loss per Share The Company’s potentially dilutive securities, which include preferred stock and stock options, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following shares from the computation of diluted net loss per share attributable to common stockholders as of December 31, 2020 and 2019 because including them would have had an anti-dilutive effect: December 31, 2020 2019 Redeemable convertible preferred stock 36,756,497 36,756,497 Options to purchase common stock 3,814,659 2,307,640 Convertible notes (1) 17,313,456 15,759,821 Series D warrants 183,438 183,438 (1) Convertible note shares are calculated using the Series D Preferred Stock issue price of $4.50 per share and includes interest accrued as of December 31, 2020 and 2019.

Related Party Transactions

Related Party Transactions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Related Party Transactions [Line Items]
Related Party Transactions	14. Related Party Transactions In July of 2020, a member of Old Clarus’ board of directors, who is now a member of the Company’s board of directors, temporarily expanded his director duties as an executive director, at the request of the Company’s board of directors. As executive director, this member received a total of $0.2 million in consulting fees during the nine months ended September 30, 2021.	14. Related Party Transactions During the year ended December 31, 2020, a member of the Company’s board of directors, temporarily expanded his director duties as an executive director, at the request of the Company’s board of directors. As executive director, this member received a total of $0.1 million in consulting fees during the year ended December 31, 2020.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Event [Line Items]
Subsequent Events	15. Subsequent Events Issuance of Convertible Notes In March and April of 2021, the Company entered into additional note purchase agreements (the “2021 Notes”) pursuant to which the Company borrowed an aggregate of $12.5 million from existing investors. Outstanding balances under the 2021 Notes accrue interest at a rate of 8%, compounded daily, and have a maturity date of September 1, 2025 Proposed Merger On April 27, 2021, the Company executed a definitive merger agreement with Blue Water Acquisition Corporation (“Blue Water”, or “BLUW”), a Special Purpose Acquisition Company. Upon the completion of the proposed business combination transaction, the convertible noteholders and Series D Preferred Stock shareholders of Clarus will exchange their interests in Clarus for shares of common stock of continuing public company or Combined Entity. The proposed merger is expected to be accounted for as a “reverse recapitalization” in accordance with U.S. GAAP. Under the reverse recapitalization model, the Business Combination will be treated as Clarus issuing equity for the net assets of BLUW, with no goodwill or intangible assets recorded. Under this method of accounting, Blue Water will be treated as the “acquired” company for financial reporting purposes. This determination is primarily based on the fact that subsequent to the merger, the Company’s stockholders are expected to have a majority of the voting power of the combined company, the Company will comprise all of the ongoing operations of the combined entity, the Company will comprise a majority of the governing body of the combined company, and the Company’s senior management will comprise all of the senior management of the combined company. As a result of the proposed merger, Blue Water will be renamed Clarus Therapeutics Holdings, Inc., or Combined Entity, and Clarus will become a wholly owned subsidiary of Combined Entity. Blue Water is expected to receive net proceeds of approximately $198.2 million upon the closing of the proposed merger transaction, assuming no redemptions are affected by stockholders of Blue Water, and will operate under the current Clarus management team upon the closing of the proposed merger. In connection with the proposed merger, the Company’s convertible noteholders and senior secured noteholders agreed to provide $25.0 million in additional capital to the Company following the close of the merger. All such proceeds will convert to shares of Blue Water common stock at a price of $10.00 per share at the merger closing. The closing of the proposed merger is a precondition to the additional financing. Subject to the terms of the merger agreement, at the effective time of the merger (the “Effective Time”), each share of Clarus’s redeemable convertible Series D Preferred Stock issued and outstanding immediately prior to the Effective Time shall be converted into shares of the combined Company’s common stock and all principal and accrued interest under the Company’s Series D convertible notes shall convert into shares of common stock of the surviving entity, subject to adjustment in accordance with the exchange ratio. All other series of preferred stock, common stock and stock options will be cancelled and extinguished upon completion of the proposed merger. In addition, Clarus’s existing equity incentive plans will be terminated. Any unexpired, outstanding Series D Warrants will remain outstanding and become exercisable shares of common stock of the surviving entity, subject to adjustment in accordance with the exchange ratio. The boards of directors of both Blue Water and Clarus have approved the proposed transaction. Completion of the transaction is expected to be in the third quarter of 2021, and is subject to, among other things, the approval by Blue Water’s shareholders, satisfaction of the conditions stated in the merger agreement and other customary closing conditions. There is no assurance that the transaction will be consummated.

Accounting Policies, by Policy

Accounting Policies, by Policy (Policies)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Line Items]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements and accompanying notes have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments necessary to fairly present the financial position of the Company as of September 30, 2021 and December 31, 2020, the results of operations for the three and nine months ended September 30, 2021 and 2020 and its cash flows for the nine months ended September 30, 2021 and 2020 have been included and are of a normal, recurring nature except as otherwise disclosed. These condensed consolidated financial statements and notes thereto have been prepared under the presumption that users of the financial information have either read or have access to the audited financial statements for the latest year ended December 31, 2020. As a result of the Merger, the shares and corresponding capital amounts and loss per share related to Old Clarus’s outstanding convertible preferred stock and common stock prior to the Merger have been retroactively restated to reflect the actual shares for which the Series D preferred stock converted into as a result of the conversion terms in the Merger Agreement. For additional information on the Business Combination, please refer to Note 3, Business Combination	Basis of Presentation The financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”).
Use of Estimates	Use of Estimates Preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenues and expenses during the reporting period covered by the condensed financial statements and accompanying notes. The most significant estimates relate to determination of fair value of the Company’s common stock and common stock warrants, stock-based compensation, notes, royalty obligation and the valuation of embedded derivatives. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, and records adjustments when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from those estimates.	Use of Estimates Preparation of the financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period covered by the financial statements and accompanying notes. The most significant estimates relate to determination of fair value of the Company’s common stock and common stock warrants, stock-based compensation, notes, royalty obligation and the valuation of embedded derivatives. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, and records adjustments when facts and circumstances dictate. As future events and their effects cannot be determined with precision, actual results could differ from those estimates.
Cash and Cash Equivalents		Cash and Cash Equivalents Cash and cash equivalents and represent cash and highly liquid investments with an original contractual maturity at the date of purchase of three months or less. As of December 31, 2020 and 2019, cash and cash equivalents included government-backed money market funds.
Concentration of Credit Risk		Concentrations of Risk Substantially all of the Company’s cash and money market funds are held with a single financial institution. Due to its size, the Company believes this financial institution represents minimal credit risk. Deposits in this institution may exceed the amount of insurance provided on such deposits by the Federal Deposit Insurance Corporation for U.S. institutions. The Company has not experienced any losses on its deposits of cash and cash equivalents. Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company’s accounts receivable balance is compromised solely from transactions with the Company’s single third-party logistics provider, or 3PL. The Company monitors economic conditions to identify facts or circumstances that may indicate that any of its accounts receivable are at risk of collection. The Company depends on two third-party suppliers for its supply of T-undecanoate
Fair Value of Financial Instruments		Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The three levels of inputs that may be used to measure fair value are defined below: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3: Unobservable inputs for the asset or liability (i.e. supported by little or no market activity). Level 3 inputs include management’s own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk). To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.
Derivative warrant liabilities	Derivative warrant liabilities The Company does not use derivative instruments to hedge exposures to cash flow, market, or foreign currency risks. The Company evaluates all of its financial instruments, including issued stock purchase warrants, to determine if such instruments are liabilities, derivatives or contain features that qualify as embedded derivatives, pursuant to ASC 480 and ASC 815 Derivatives and Hedging re-assessed The Private Placement Warrants are recognized as derivative liabilities in accordance with ASC 815. Accordingly, the Company recognizes the warrant instruments as liabilities at fair value and adjusts the instruments to fair value at each reporting period. The fair value of the Private Placement warrants has been estimated using a modified Monte Carlo simulation model at inception and subsequently at each measurement date using the Black-Scholes model. The liabilities are subject to re-measurement The fair value of warrants issued in connection with the IPO were initially measured at fair value using a Monte Carlo simulation model and have subsequently been measured based on the listed market price of such warrants.
Income Taxes		Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, the Company determines deferred tax assets and liabilities on the basis of the differences between the financial statement and tax bases of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes deferred tax assets to the extent that it believes that these assets are more likely than not to be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning The Company records uncertain tax positions in accordance with ASC 740 on the basis of a two-step more-likely-than-not The Company recognizes interest and penalties related to unrecognized tax benefits on the income tax expense line in the accompanying statement of operations. As of December 31, 2020 and 2019, no accrued interest or penalties are included on the related tax liability line in the balance sheet.
Net Income (Loss) Per Share	Net Income (Loss) Per Share Basic net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of common shares outstanding during the period. Diluted net income (loss) per share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common stock. Net income (loss) per share attributable to common stockholders is calculated using the two-class as-converted When considering the impact of the convertible equity instruments, diluted net income (loss) per share is computed using the more dilutive of (a) the two-class if-converted	Basic and Diluted Loss per Share Basic and diluted net loss per common share is determined by dividing net loss attributable to common stockholders by the weighted average common shares outstanding. Basic net loss per share is determined using the weighted average number of shares of common stock outstanding during each period. Diluted net loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible preferred stock, warrants and stock options, which would result in the issuance of incremental shares of common stock. The computation of diluted net loss per shares does not include the conversion of securities that would have an anti-dilutive effect. The basic and diluted computations of net loss per share for the Company are the same because the effects of the Company’s convertible securities would be anti-dilutive. See Note 13, Net Loss per Share
Recent Accounting Standards		Recently Adopted Accounting Pronouncements In January 2016, the FASB issued ASU 2016-01, Financial Instruments — Overall (Subtopic 825-10): 2016-01”). 2016-01 2016-01
Reclassifications		Reclassifications Certain reclassifications have been made to the Company’s prior year financial statements to conform to the Company’s current year presentation. These reclassifications had no effect on the Company’s previously reported results of operations or accumulated deficit.
Segment Information		Segment Information The Company’s chief operating decision maker manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. All of the Company’s long-lived assets are held in the United States.
Accounts Receivable, Net		Accounts Receivable, Net Accounts receivable are stated at net realizable value. On a periodic basis, management evaluates its accounts receivable and determines whether to provide an allowance or if any accounts should be written off based on a past history of write-offs, collections and current credit conditions. A receivable is considered past due if the Company has not received payments based on agreed-upon terms. The Company generally does not require any security or collateral to support its receivables. The Company performs ongoing evaluations of its customers.
Inventory		Inventory Inventory is stated at the lower of cost or net realizable value. Cost is determined using the first-in, first-out
Property and Equipment, net		Property and Equipment, net Property and equipment are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the respective assets, as follows: Asset Class Estimated Computer and office equipment 3 years Furniture and fixtures 7 years Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations. Repair and maintenance costs are charged to expense as incurred
Impairment of Long-Lived Assets		Impairment of Long-Lived Assets The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset group may not be recoverable. There were no charges as a result of impairment losses for the years ended December 31, 2020 or 2019.
Deferred Financing Costs		Deferred Financing Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process in-process
Redeemable Convertible Preferred Stock		Redeemable Convertible Preferred Stock The Company has adopted current accounting guidance in regard to accounting for certain financial instruments with characteristics of both liabilities and equity and for the classification and measurement of redeemable securities. This guidance requires companies with mandatorily redeemable features in their equity instruments to be classified separately from equity. The Company measures these instruments by recognizing changes in redemption value immediately as they occur and adjust the carrying amount of the instrument to equal the redemption value at the end of each reporting period. In accordance with this guidance, the Series A Preferred Stock, Series B Preferred Stock, Series C Preferred Stock and Series D Preferred Stock have been classified separately from equity in the accompanying balance sheets.
Revenue Recognition		Revenue Recognition In accordance with ASC 606, Revenue from Contracts with Customers has assessed the existence of a significant financing component in the agreements with its customers. The trade payment terms with its customers do not exceed one year and therefore, no amount of consideration has been allocated as a financing component. Taxes collected related to product sales are remitted to governmental authorities and are excluded from revenue. Net Product Sales The Company began selling JATENZO in February 2020, in the United States through a 3PL which takes title and control of the goods. The 3PL distributes the product to wholesale distributors (collectively the “Distributors”), with whom the Company has entered into formal agreements for delivery to retail pharmacies. The Company has also entered into arrangements with payors that provide government mandated and/or privately negotiated rebates, chargebacks and discounts for the purchase of the Company’s products. The Company recognizes revenue on sales of JATENZO when the customer obtains control of the product, which occurs at a point in time, typically upon delivery. Product revenues are recorded at the product’s wholesale acquisition costs, net of applicable reserves for variable consideration that are offered within contracts between the Company and its customers, wholesale distributors, payors, and other indirect customers relating to the sale of JATENZO. Components of variable consideration include government and commercial contract rebates, product returns, chargebacks, commercial co-payment The amount of variable consideration which is included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognition under contracts will not occur in a future period. The Company’s analyses contemplate the application of the constraint in accordance with ASC 606. Actual amounts of consideration ultimately received may differ from its estimates. If actual results in the future vary from its estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known.
Cost of Product Sales		Cost of Product Sales Cost of product sales include manufacturing and distribution costs, the cost of drug substance, FDA program fees and a reserve for short-dated, obsolete inventory. The Company began capitalizing inventory upon FDA approval of JANTENZO ®
Research and Development Expenses		Research and Development Expenses Research and development expenses include salaries and benefits, clinical trials costs, contract services and manufacturing development costs. Research and development expenses are charged to operations as they are incurred. The Company follows the provisions of the Research and Development Topic of the Codification which requires the Company to defer and capitalize nonrefundable advance payments made for goods or services to be used in research and development activities until the goods have been delivered or the related services have been performed. If the goods are no longer expected to be delivered or the services are no longer expected to be performed, the Company would be required to expense the related capitalized advance payments. The Company had no capitalized nonrefundable advance payments and no refundable advance payments as of December 31, 2020 or 2019.
Leases		Leases The Company leases office space and recognizes related rent expense on a straight-line basis over the term of the lease.
Stock-Based Compensation		Stock-Based Compensation The Company accounts for all stock-based compensation awards granted as stock-based compensation expense at fair value. The Company’s stock-based payments include stock options and grants of common stock, restricted for vesting conditions. The measurement date for awards is the date of grant, and stock-based compensation costs are recognized as expense over the requisite service period, which is generally the vesting period, on a straight-line basis. Stock-based compensation expense is classified in the accompanying statements of operations based on the function to which the related services are provided. The Company recognizes stock-based compensation expense for the portion of awards that have vested. Forfeitures are recorded as they occur. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model.
Patents and Trademarks		Patents and Trademarks All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty of the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the statement of operations.
Comprehensive Loss		Comprehensive Loss The Company’s comprehensive loss was the same as its reported net loss for all periods presented.
Emerging Growth Company Status		Emerging Growth Company Status The Company is expected to be an “emerging growth company” (“EGC”) upon merger, as defined in the Jumpstart Our Business Startups Act (“JOBS Act”) and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not EGCs. The Company may take advantage of these exemptions until it is no longer an EGC under Section 107 of the JOBS Act, which provides that an EGC can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company expects to elect to avail itself of the extended transition period and, therefore, while the Company is an EGC it will not be subject to new or revised accounting standards the same time that they become applicable to other public companies that are not EGCs, unless it chooses to early adopt a new or revised accounting standard.
Recently Issued Accounting Pronouncements Not Yet Adopted		Recently Issued Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) 2016-02”) . ASU 2016-02, right-of-use In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments 2016-13”), 2016-13 available-for-sale 2016-13 2016-13 2016-13 In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) 2019-12”) : Simplifying the Accounting for Income Taxes, In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848), Facilitation of the Effects of Reference Rate Reform on Financial Reporting 2020-4”), 2020-04 2020-04 In June 2020, the FASB issued ASU 2020-06, Debt — Debt with Conversion and Other Options (Subtopic 470-20) 815-40): 2020-06”). ASU 2020-06 2020-06

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Line Items]
Property, Plant and Equipment	December 31, 2020 2019 Office equipment and computer hardware $ 99 $ 96 Furniture and fixtures 109 51 Total property and equipment 208 147 Less accumulated depreciation (144 ) (126 ) Property and equipment, net $ 64 $ 21
Blue Water Acquisition Corp [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment	Property and equipment are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the respective assets, as follows: Asset Class Estimated Computer and office equipment 3 years Furniture and fixtures 7 years

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Fair Value Measurements [Line Items]
Schedule of fair value hierarchy	The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: September 30, 2021 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 20,001 $ 20,001 $ — $ — Total assets $ 20,001 $ 20,001 $ — $ — Liabilities Private placement warrant liability $ 6,465 $ — $ — $ 6,465 Total Liabilities $ 6,465 $ — $ — $ 6,465 December 31, 2020 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 7,205 $ 7,205 $ — $ — Total assets $ 7,205 $ 7,205 $ — $ —	The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: December 31, 2020 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 7,205 $ 7,205 $ — $ — Total assets $ 7,205 $ 7,205 $ — $ — Liabilities Warrant liability $ — $ — $ — $ — Derivative liability — — — — Total liabilities $ — $ — $ — $ — December 31, 2019 (in thousands) Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market funds $ 1,628 $ 1,628 $ — $ — Total Assets $ 1,628 $ 1,628 $ — $ — Liabilities Warrant liability $ 551 $ — $ — $ 551 Derivative liability 65,006 — — 65,006 Total liabilities $ 65,557 $ — $ — $ 65,557
Schedule of changes in the fair value of the Company's warrant liability	The following table sets forth a summary of changes in the fair value of the Company’s warrant liability for the three and nine months ended September 30, 2021 (in thousands): Beginning warrant liability balance $ — Private placement warrant liability assumed 14,075 Change in fair value of warrant liability (7,610 ) Balance at September 30, 2021 $ 6,465	The following table sets forth a summary of changes in the fair value of the Company’s warrant liability (in thousands): Balance at December 31, 2018 $ 689 Change in fair value of warrants (138 ) Balance at December 31, 2019 $ 551 Change in fair value of warrants (551 ) Balance at December 31, 2020 $ —
Schedule of changes in the fair value of the Company's derivative liability		The following table sets forth a summary of changes in the fair value of the Company’s derivative liability (in thousands): Balance at December 31, 2018 $ 50,020 2019 Notes issued 14,861 Change in fair value of derivative 125 Balance at December 31, 2019 $ 65,006 2020 Notes issued 1,334 Change in fair value of derivative (66,340 ) Balance at December 31, 2020 $ —

Inventory (Tables)

Inventory (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of inventory	Inventory consisted of the following as of September 30, 2021 and December 31, 2020 (in thousands): September 30, December 31, 2021 2020 Raw material $ 6,738 $ 4,225 Work-in-process 5,778 — Finished goods 7,865 9,475 Total inventory 20,381 13,700 Inventory reserve (7,901 ) (7,843 ) Total inventory, net of reserve $ 12,480 $ 5,857	December 31, 2020 2019 Raw material $ 4,225 $ 94 Work-in-process — 4,664 Finished goods 1,632 2,203 Total $ 5,857 $ 6,961

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combination, Description [Abstract]
Summary of net proceeds from the Business Combination	The following table summarizes the elements of the net proceeds from the Business Combination as of September 30, 2021 (in thousands): Cash – Blue Water Trust Account and cash (net of redemptions) $ 25,394 Less: Equity issuance costs and other costs paid prior to September 30, 2021 (8,386 ) Net Proceeds from the Business Combination $ 17,008
Summary of common stock issued in consummation of business combination	The following table summarizes the number of shares of Common Stock outstanding immediately following the consummation of the Business Combination: Blue Water shares outstanding prior to the Business Combination 3,839,468 Conversion of Old Clarus Series D Preferred Stock 4,901,564 Conversion of Old Clarus convertible notes 8,529,846 Conversion of additional capital provided by Old Clarus convertible note and senior note holders 2,549,939 Conversion of Senior Secured Note principal and royalty rights 1,905,000 Total shares of the Company’s common stock outstanding immediately following the Business Combination 21,725,817
Summary of impact of the transaction on the condensed consolidated statement of stockholder's equity	The following table summarizes the impact of the transaction on the condensed consolidated statement of stockholder’s deficit as of September 9, 2021: Additional Paid Conversion of senior notes and royalty obligation carrying value $ 28,254 Conversion of Old Clarus convertible notes carrying value 103,333 Assumption of private placement warrant liabilities (14,075 ) Total reverse recapitalization impact on statement of equity $ 117,512

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of property and equipment	December 31, 2020 2019 Office equipment and computer hardware $ 99 $ 96 Furniture and fixtures 109 51 Total property and equipment 208 147 Less accumulated depreciation (144 ) (126 ) Property and equipment, net $ 64 $ 21

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of accrued expenses	Accrued expenses consisted of the following (in thousands): September 30, December 31, 2021 2020 Selling and marketing costs $ 5,905 $ 3,468 Employee compensation and related benefits 1,074 1,090 Professional fees 388 73 Other 6 — Total $ 7,373 $ 4,631	December 31, 2020 2019 Selling and marketing costs $ 3,468 $ 698 Employee compensation and related benefits 1,090 569 Other research costs — 61 Professional Fees 73 426 Other — 13 Total $ 4,631 $ 1,767

Debt (Tables)

Debt (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of senior secured notes		Issuance Year Aggregate 2016 $ 18,000 2017 14,000 2018 9,300 2019 18,389 2020 1,611 Total $ 61,300
Schedule of carrying value of convertible notes	As of December 31, 2020, the carrying value of the Convertible Notes consisted of (in thousands): December 31, 2020 Principal amount $ 61,300 Accrued and unpaid interest 17,287 Unamortized debt discount (676 ) Total $ 77,911	December 31, 2020 2019 Principal amount $ 61,300 $ 59,689 Accrued and unpaid interest 17,287 11,230 Unamortized debt discount (676 ) — Total $ 77,911 $ 70,919
Schedule of carrying value of senior notes	The carrying value of the Company’s senior secured notes consisted of the following (in thousands): September 30, December 31, 2021 2020 Principal amount $ 43,125 $ 50,000 Accrued and unpaid interest 1,234 1,278 Unamortized debt discount (8,062 ) (9,376 ) Total $ 40,339 $ 41,902	December 31, Principal amount $ 50,000 Accrued and unpaid interest 1,278 Unamortized debt discount (9,376 ) Total $ 41,902
Schedule of future principal payments of the senior secured notes	Future principal payments of the senior secured notes are as follows (in thousands): Years ended December 31, Amount 2021 (remaining 3 months) $ — 2022 6,000 2023 15,125 2024 14,000 2025 8,000 Total $ 43,125	Years ending December 31, Amount 2021 $ — 2022 7,500 2023 15,000 2024 17,500 2025 10,000 Total $ 50,000
Schedule of carrying value of the Company's royalty obligation		December 31, Value assigned to royalty obligation at inception $ 7,211 Non-cash 2,051 Royalty obligation — ending balance $ 9,262

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2020
Redeemable Convertible Preferred Stock [Abstract]
Schedule of redeemable convertible preferred stock	There were no shares of redeemable convertible preferred stock issued during the years ended December 31, 2020 and December 31, 2019 As of December 31, 2020, and 2019, preferred stock consisted of the following (in thousands, except for share data): December 31, 2020 Preferred Preferred Carrying Liquidation Common Series A Preferred Stock 2,500,000 2,500,000 $ 9,170 $ 9,170 2,500,000 Series B Preferred Stock 5,066,637 5,066,637 15,118 15,118 5,066,637 Series C Preferred Stock 9,438,744 9,438,744 20,057 20,057 9,438,744 Series D Preferred Stock 36,335,255 19,751,117 153,850 153,850 19,751,117 Total 53,340,636 36,756,498 $ 198,195 $ 198,195 36,756,498 December 31, 2019 Preferred Preferred Carrying Liquidation Common Series A Preferred Stock 2,500,000 2,500,000 $ 8,491 $ 8,491 2,500,000 Series B Preferred Stock 5,066,637 5,066,637 13,998 13,998 5,066,637 Series C Preferred Stock 9,438,744 9,438,744 18,571 18,571 9,438,744 Series D Preferred Stock 36,335,255 19,751,117 142,453 142,453 19,751,117 Total 53,340,636 36,756,498 $ 183,513 $ 183,513 36,756,498

Common Stock (Tables)

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2020
Common Stock [Abstract]
Schedule of common stock for the potential conversion of outstanding preferred stock and exercise of stock options	As of December 31, 2020, and 2019, the Company has reserved the following shares of common stock for the potential conversion of outstanding preferred stock and exercise of stock options: December 31, 2020 2019 Preferred stock, as converted 36,756,498 36,756,498 Options to purchase common stock 3,814,659 2,307,640 Series D warrants 183,438 183,438 Remaining shares reserved for future issuance 1,350,481 3,156,710 Total 42,105,076 42,404,286

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of stock option activity under the Plans		The following table summarizes stock option activity under the Plans: Number of Weighted Weighted Aggregate Outstanding as of December 31, 2019 2,307,640 $ 1.70 5.1 $ — Granted 1,806,229 2.69 Exercised — — Cancelled (142,500 ) 1.49 Forfeited (156,710 ) 1.98 Outstanding as of December 31, 2020 3,814,659 $ 2.17 6.8 $ — Options vested and exercisable as of December 31, 2020 2,320,686 $ 1.86 6.9 $ —
Schedule of stock-based compensation expense	Stock-Based Compensation Expense Stock-based compensation expense is as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Selling and marketing $ 6 $ — $ 15 $ — Research and development 19 15 52 54 General and administrative 182 75 491 180 Total stock-based compensation expense $ 207 $ 90 $ 559 $ 234	Stock-based compensation expense is as follows (in thousands): Years Ended 2020 2019 Selling and marketing $ 183 $ — Research and development 189 108 General and administrative 453 251 Total stock-based compensation expense $ 825 $ 359
Schedule of weighted-average assumptions		The fair value was estimated on the date of grant using the Black-Scholes option-pricing model, with the following weighted-average assumptions: Years Ended 2020 2019 Expected volatility 59.66 % 58.13 % Weighted-average risk-free interest rate 1.59 % 2.58 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 4.00 4.00

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Schedule of net deferred tax assets	The net deferred income tax asset balance related to the following (in thousands): Year Ended 2020 2019 Deferred tax assets Stock compensation $ 64 $ 12 Accruals and other 4,151 1,060 Debt discount 483 — Royalty liability 2,272 — Net operating loss carryforwards 51,918 44,641 Tax credits 6,774 6,774 Total deferred tax assets 65,662 52,487 Less: valuation allowance (65,662 ) (52,487 ) Deferred tax assets, net $ — $ —
Schedule of federal income tax rate to the Company's effective tax rate	A reconciliation of the Company’s statutory income tax rate to the Company’s effective income tax rate is as follows (in thousands): Year Ended December 31, 2020 2019 Income at U.S. statutory rate $ 912 21.00 % $ (8,746 ) 21.00 % State taxes, net of federal benefit (1,583 ) -36.45 % (1,171 ) 2.81 % Change in fair value (14,047 ) -323.39 % — 0.00 % Interest expense 1,410 32.46 % 5,009 -12.03 % Stock compensation 127 2.93 % 1,139 -2.73 % Permanent differences 6 0.13 % 3 -0.01 % Valuation allowance 13,175 303.32 % 3,561 -8.55 % Other — 0.00 % 205 -0.49 % $ — 0.00 % $ — 0.00 %
Schedule of company's valuation allowance	The Company’s valuation allowance for the year ended December 31, 2020 and 2019 is as follows (in thousands): Year Ended 2020 2019 Valuation allowance at beginning of year $ 52,487 $ 48,926 Increases recorded to income tax provision 13,175 3,561 Valuation allowance at the end of year $ 65,662 $ 52,487

Commitments and Contingencies

Commitments and Contingencies (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of lease payments under non-cancellable lease agreements	A summary of the Company’s future minimum lease payments required under non-cancellable Years ended December 31, Amount 2021 (remaining 3 months) $ 24 2022 16 2023 — 2024 — 2025 — Total $ 40	A summary of the Company’s future minimum lease payments required under non-cancellable Years ending December 31, Amount 2021 $ 95 2022 16 2023 — 2024 — 2025 — Total $ 111

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of basic and diluted earnings (loss) per share attributable to common stockholders	Basic and diluted earnings (loss) per share attributable to common stockholders are calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Numerator: Net loss (income) $ (2,769 ) $ 5,406 $ (36,315 ) $ 4,067 Earnings attributable to Old Clarus participating warrants (1) — (10 ) — (8 ) Gain on extinguishment of convertible notes (2) 412 — 412 — Net (loss) income attributable to common stockholders, basic (2,357 ) 5,396 (35,903 ) 4,059 Effect of convertible notes (3) — (19,139 ) — (48,338 ) Net loss attributable to common stockholders, diluted $ (2,357 ) $ (13,743 ) $ (35,903 ) $ (44,279 ) Denominator: Weighted-average common shares attributable to common stockholders, basic 9,153,848 4,901,564 6,318,992 4,901,564 Effect of convertible notes (4) — 16,927,006 — 16,927,006 Weighted average number of common shares - diluted 9,153,848 21,828,570 6,318,992 21,828,570 Net loss per common share attributable to common stockholders, basic $ (0.26 ) $ 1.10 $ (5.68 ) $ 0.83 Effect of convertible notes — (1.73 ) — (2.86 ) Net loss per common share attributable to common stockholders, diluted $ (0.26 ) $ (0.63 ) $ (5.68 ) $ (2.03 ) (1) The loss attributable to Old Clarus participating warrants relates to the total earnings attributable to the 9,246 Old Clarus participating warrants using the two-class (2) The gain on extinguishment of convertible notes relates to the difference between the carrying value of the convertible notes upon conversion to shares and the fair value of the shares exchanged which requires adjustment to the numerator when calculating basic EPS. (3) The effect of the convertible notes on the numerator for the three and nine months ended September 30, 2020 relates to the impact that the convertible notes had on net income during the period, and are removed from net income when calculating net income (loss) attributable to common stockholders diluted using the if-converted (4) The effect of convertible notes on the denominator for the three and nine months ended September 30, 2020 was calculated based on the carrying value of the convertible notes balance at September 30, 2020, converted at the series D price of $4.50 per share and are added back to the denominator when calculating diluted EPS using the if-converted
Schedule of computation of diluted net loss per share attributable to common stockholders	The Company excluded the following shares from the computation of diluted net loss per share attributable to common stockholders as of September 30, 2021 and 2020 because including them would have had an anti-dilutive effect: Three Months September 30, Nine Months September 30, 2021 2020 2021 2020 Convertible notes — — — — Old Clarus Warrants 9,246 — 9,246 —	The Company excluded the following shares from the computation of diluted net loss per share attributable to common stockholders as of December 31, 2020 and 2019 because including them would have had an anti-dilutive effect: December 31, 2020 2019 Redeemable convertible preferred stock 36,756,497 36,756,497 Options to purchase common stock 3,814,659 2,307,640 Convertible notes (1) 17,313,456 15,759,821 Series D warrants 183,438 183,438 (1) Convertible note shares are calculated using the Series D Preferred Stock issue price of $4.50 per share and includes interest accrued as of December 31, 2020 and 2019.

Organization and Description _2

Organization and Description of Business Operations (Detail)	Sep. 01, 2021shares	Dec. 17, 2020USD ($)$ / sharesshares	Sep. 30, 2021USD ($)Day$ / sharesshares	Sep. 30, 2020$ / shares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Remaining additional capital amount
Shares issued in Initial Public Offering | shares		5,750,000
Offering costs		$ 3,700,000
Deferred underwriting commissions		$ 2,000,000
Secured debt			$ 25,000,000
Remaining Additional Capital			$ 25,000
Conversions Of Stock Shares Converted | shares			13,431,410
Aggregate shares of common stock (in Shares) | shares			1,500,000
Sponsor shares (in Shares) | shares	135,000
Accumulated deficit			$ 317,400,000
Accumulated deficit			(317,352,000)		$ (325,781,000)	$ (316,269,000)
Description of forbearance					The Company is also in forbearance on its March 12, 2020 senior secured notes as it was unable to maintain at least $10.0 million in cash and cash equivalents as of the last day of each calendar month beginning December 2020 and was unable to pay the required $3.1 million interest payment due in March 2021. In accordance with the related forbearance agreement, the Company will need to maintain at least $2.5 million of cash and cash equivalents as of the last day of each calendar month until the proposed SPAC merger (see below).
Owned percentage					100.00%
Additional investment amount					$ 25,000,000
Working capital			$ 19,100,000
Number of issued patents | Day			5
Conversion of additional capital provided to shares (in shares) | shares			2,549,939
Net Proceeds Amount			$ 17,000,000
Conversion of stock conversion price per share | $ / shares				$ 10.20
Senior Note Initial Principal Balance exchanged for shares			$ 10,000,000
Common stock, shares reallocated to the senior secured noteholders for the satisfaction of debt related agreement | shares			405,000
Old Clarus Equity Holders [Member]
Remaining additional capital amount
Common stock, shares reallocated to the senior secured noteholders for the satisfaction of debt related agreement | shares	270,000
Common Stock [Member]
Remaining additional capital amount
Price per share (in Dollars per share) | $ / shares			$ 10
Over-Allotment Option [Member]
Remaining additional capital amount
Number of units issued in transaction (in Shares) | shares		750,000
Price per warrant (in Dollars per share) | $ / shares		$ 10
Gross proceeds of private placement		$ 57,500,000
Private Placement [Member]
Remaining additional capital amount
Warrants shares, issued (in Shares) | shares		3,445,000
Gross proceeds of private placement			$ 3,400,000
Private Placement [Member] | Blue Water Acquisition Corp [Member]
Remaining additional capital amount
Price per warrant (in Dollars per share) | $ / shares		$ 1
Series A Redeemable Convertible Preferred Stock
Remaining additional capital amount
Accumulated deficit					325,800,000
Cumulative Accretion Value					94,000,000
Series D Redeemable Convertible Preferred Stock
Remaining additional capital amount
Cumulative non-cash interest related to previously issued convertible debt					$ 97,600,000
Blue Water IPO [Member]
Remaining additional capital amount
Net proceeds of initial public offering		$ 58,700,000
Price per share (in Dollars per share) | $ / shares		$ 10.20

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details)- Property and Equipment, net	12 Months Ended
	Dec. 31, 2020
Computer and office equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($)	Sep. 09, 2021	Dec. 17, 2020	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2017
Fair Value Measurements Details [Line Items]
Warrant liability and derivative liability amount					$ 0
Fair value description					As the fair value of Series D Preferred Stock at December 31, 2020 was less than the Series D Preferred Stock issuance price of $4.50, the fair value of the Series D warrants was reduced to zero.
Aggregate borrowing amount					$ 61,300,000
Financing discount percentage					20.00%
Derivative liability description					As the fair value of Series D Preferred Stock at December 31, 2020 was less than the Series D Preferred Stock issuance price of $4.50, the fair value of the derivative liability related to the Company’s convertible notes was reduced to zero.
Aggregate borrowing amount of convertible notes					$ 61,300,000
Reverse Recapitalization [Member]
Fair Value Measurements Details [Line Items]
Class Of Warrant Or Rights Issued During Period Shares New Issues	9,195,000
PublicWarrantsMember | Reverse Recapitalization [Member]
Fair Value Measurements Details [Line Items]
Class Of Warrant Or Rights Issued During Period Shares New Issues	5,750,000
Private Placement Warrants [Member] | Warrants And Rights Subject To Mandatory Redemption Trigger Price Equals To Eleven Point Zero Five Dollars Per Share [Member]
Fair Value Measurements Details [Line Items]
Issuance price (in Dollars per share)			$ 11.50	$ 11.50
Share Price			$ 11.50	$ 11.50
Private Placement Warrants [Member] | Reverse Recapitalization [Member]
Fair Value Measurements Details [Line Items]
Class Of Warrant Or Rights Issued During Period Shares New Issues	3,445,000
Fair Value, Inputs, Level 1, 2 and 3 [Member]
Fair Value Measurements Details [Line Items]
Transfers between levels				$ 0	0	$ 0
Transfers between levels			$ 0	0	$ 0	$ 0
Series D Preferred Stock [Member]
Fair Value Measurements Details [Line Items]
Issuance price (in Dollars per share)					$ 4.50
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					183,438
Exercise Price of Warrants or Rights					$ 4.50
Share Price					$ 4.50
Series D Preferred Stock [Member] | Class Of Warrants Maturity At July Fourteen Two Thousand And Twenty One [Member]
Fair Value Measurements Details [Line Items]
Warrants and rights outstanding maturity date							Jul. 14, 2021
Class Of Warrant Or Rights Issued During Period Shares New Issues		61,146					122,292
Series D Preferred Stock [Member] | Class Of Warrants Maturity At April Nine Two Thousand And Twenty Three [Member]
Fair Value Measurements Details [Line Items]
Warrants and rights outstanding maturity date							Apr. 9, 2023
Class Of Warrant Or Rights Issued During Period Shares New Issues							61,146
Series D Preferred Stock [Member] | Exercise Of Warrants Event [Member]
Fair Value Measurements Details [Line Items]
Exercise Price of Warrants or Rights	$ 29.74
Stock Issued During Period Shares Issued for Exercise of Warrants	9,246
Class Of Warrant Or Rights Issued During Period Shares New Issues	61,146
Warrant [Member]
Fair Value Measurements Details [Line Items]
Derivative liability			$ 6,400,000	$ 6,400,000

Fair Value Measurements (Deta_2

Fair Value Measurements (Details) - Schedule of fair value hierarchy - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value Measurements (Details) - Schedule of fair value hierarchy [Line Items]
Derivative warrant liabilities - private warrants	$ 6,465
Money market funds	20,001	$ 7,205
Total assets	20,001	7,205
Total Liabilities	6,465
Quoted Prices in Active Markets (Level 1) [Member]
Fair Value Measurements (Details) - Schedule of fair value hierarchy [Line Items]
Money market funds	20,001	7,205
Total assets	20,001	7,205
Significant Other Unobservable Inputs (Level 3) [Member]
Fair Value Measurements (Details) - Schedule of fair value hierarchy [Line Items]
Derivative warrant liabilities - private warrants	6,465
Total Liabilities	$ 6,465
Fair Value, Recurring [Member]
Fair Value Measurements (Details) - Schedule of fair value hierarchy [Line Items]
Money market funds		7,205	$ 1,628
Total assets		7,205	1,628
Warrant Liability			551
Derivative Liability			65,006
Total Liabilities			65,557
Fair Value, Recurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value Measurements (Details) - Schedule of fair value hierarchy [Line Items]
Money market funds		7,205	1,628
Total assets		7,205	1,628
Warrant Liability
Derivative Liability
Total Liabilities
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value Measurements (Details) - Schedule of fair value hierarchy [Line Items]
Money market funds
Total assets
Warrant Liability
Derivative Liability
Total Liabilities
Fair Value, Recurring [Member] | Significant Other Unobservable Inputs (Level 3) [Member]
Fair Value Measurements (Details) - Schedule of fair value hierarchy [Line Items]
Money market funds
Total assets
Warrant Liability			551
Derivative Liability			65,006
Total Liabilities			$ 65,557

Fair Value Measurements (Deta_3

Fair Value Measurements (Details) - Schedule of changes in the fair value of the Company's warrant liability - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Beginning warrant liability balance		$ 551	$ 551	$ 689
Change in fair value of warrants	(7,610)	$ (541)	(551)	(138)
Balance at September 30, 2021				$ 551
Private Placement Warrant Liabilites [Member]
Beginning warrant liability balance	0
Private placement warrant liability assumed	14,075
Change in fair value of warrants	(7,610)
Balance at September 30, 2021	$ 6,465		$ 0

Fair Value Measurements (Deta_4

Fair Value Measurements (Details) - Schedule of Changes In The Fair Value Of The Company's Derivative Liability - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Changes In The Fair Value Of The Company S Derivative Liability [Abstract]
Balance	$ 65,006	$ 50,020
Notes issued	1,334	14,861
Change in fair value of derivative	(66,340)	125
Balance	$ 0	$ 65,006

Inventory (Details)

Inventory (Details) $ in Millions	Dec. 31, 2020USD ($)
Inventory Disclosure [Abstract]
Reserve for inventory obsolescence	$ 7.8

Inventory (Details) - Schedule

Inventory (Details) - Schedule of inventory - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Inventory [Abstract]
Raw material	$ 6,738	$ 4,225	$ 94
Work-in-process	5,778
Work-in-process			4,664
Finished goods	7,865	9,475
Finished goods		1,632	2,203
Total	12,480	5,857	6,961
Total	20,381	13,700
Inventory reserve	(7,901)	(7,843)
Inventory	$ 12,480	$ 5,857	$ 6,961

Property and Equipment, net (De

Property and Equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 18	$ 4

Property and Equipment, net (_2

Property and Equipment, net (Details) - Schedule of property and equipment - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 208	$ 147
Less accumulated depreciation		(144)	(126)
Property and equipment, net	$ 66	64	21
Office equipment and computer hardware [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		99	96
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 109	$ 51

Accrued Expenses (Details) - Sc

Accrued Expenses (Details) - Schedule of accrued expenses - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Accrued Expenses [Abstract]
Selling and marketing costs	$ 5,905	$ 3,468	$ 698
Employee compensation and related benefits	1,074	1,090	569
Other research costs			61
Professional Fees	388	73	426
Other	6		13
Total	$ 7,373	$ 4,631	$ 1,767

Debt (Details)

Debt (Details) - USD ($)	Sep. 09, 2021	Mar. 12, 2020	Mar. 12, 2020	Feb. 28, 2023	Sep. 30, 2021	Jun. 30, 2021	Mar. 17, 2021	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	May 15, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	May 31, 2021	Mar. 01, 2021	Apr. 30, 2020	Apr. 01, 2020	Dec. 31, 2018
Debt Details [Line Items]
Borrowings amount												$ 82,300,000
Maturity date												Mar. 1, 2025
Shares issued, percentage														20.00%
Debt instrument, convertible conversion price					$ 10				$ 10			$ 10
Description of debt												The first two years provide for interest-only payments with principal payment beginning in 2022
Interest expense									$ 1,500,000	$ 1,500,000		$ 4,900,000	$ 4,500,000
Principal amount		$ 50,000,000	$ 50,000,000
Net proceeds		42,700,000	42,700,000
Transaction expenses			4,400,000
Prepaid interest		2,900,000	$ 2,900,000
Interest rate					14.50%				14.50%			14.50%		8.00%			12.50%
Royalty payments												$ 24,200,000		$ 24,200,000
Royalty Obligation Fair Value		$ 7,900,000						$ 7,900,000
Cash balance requirement					$ 21,953,000				$ 21,953,000	13,153,000		21,953,000	13,153,000	$ 7,233,000	$ 1,656,000					$ 3,032,000
Annual effective interest rate														32.30%
Convertible notes, description														the sum of (i) 1.5 times the principal amount of the Convertible Notes and (ii) accrued and unpaid interest thereon, or b) the amount that would have been payable to the noteholders if such notes had been converted to shares of Series D Preferred Stock at the Series D price immediately prior to the close of such strategic transaction.
Interest expense debt														$ 6,100	4,500
Senior secured notes, description														The senior secured notes bear interest at 12.5% and specify semiannual payments on March 1 and September 1 and have a maturity date of March 1, 2025. The first two years provide for interest-only payments and the final three years amortize the principal balance at $15.0 million, $15.0 million and $20.0 million, respectively. The senior secured notes are governed by an indenture, dated as of March 12, 2020, between the Company and the investors. The interest rate will increase to 14.50% for overdue installments in the event of default.
Business combination transaction														$ 10,000,000
Amortization of debt issuance costs and discounts												11,137,000	7,856,000	12,459,000	$ 9,005,000
Cash interest payments														3,125,000
Principal Amount Senior Secured Notes [Member]
Debt Details [Line Items]
Extinguishment of debt amount					18.6
Remaining Unamortized Debt Discount Senior Secured Notes [Member]
Debt Details [Line Items]
Extinguishment of debt amount					1.5
Carrying Amount of Royalty Obligation [Member]
Debt Details [Line Items]
Extinguishment of debt amount					11,500,000
Senior Secured Notes [Member]
Debt Details [Line Items]
Cash balance requirement								10,000,000						10,000,000
Interest expense debt									2,600,000	2,100,000		7,200,000	5,000,000
Gain loss on extinguishment of debt					300,000
Long term carrying amount					40,300,000				40,300,000			40,300,000
Amortization of debt issuance costs and discounts									700,000	700,000		2,000,000	1,500,000
Reverse Recapitalization [Member]
Debt Details [Line Items]
Cash balance requirement					8,000,000				8,000,000			8,000,000
Conversion of Senior Secured Note principal and royalty rights for common stock	1,500,000
Conversion Of Principal Senior Secured Notes and Certain Royalty Rights to Common Stock [Member] | Reverse Recapitalization [Member]
Debt Details [Line Items]
Conversion of Senior Secured Note principal and royalty rights for common stock value	$ 10,000,000
Conversion Of Principal Senior Secured Notes and Certain Royalty Rights to Common Stock [Member] | Reverse Recapitalization [Member] | Common Stock Allocation to Senior Secured Note Holders [Member]
Debt Details [Line Items]
Conversion of Senior Secured Note principal and royalty rights for common stock	405,000
Conversion Of Principal Senior Secured Notes and Certain Royalty Rights to Common Stock [Member] | Reverse Recapitalization [Member] | Common Stock Allocation to Senior Secured Noteholders From Sponsor [Member]
Debt Details [Line Items]
Conversion of Senior Secured Note principal and royalty rights for common stock	135,000
Conversion Of Principal Senior Secured Notes and Certain Royalty Rights to Common Stock [Member] | Reverse Recapitalization [Member] | Common Stock Allocation to Senior Secured Note Holders From Old Clarus Equity Holders [Member]
Debt Details [Line Items]
Conversion of Senior Secured Note principal and royalty rights for common stock	270,000
Debt Conversion [Member]
Debt Details [Line Items]
Debt instrument, convertible conversion price	$ 10.20
Debt Conversion [Member] | Reverse Recapitalization [Member]
Debt Details [Line Items]
Debt instrument, convertible conversion price	$ 10.20
Additional Principal Senior Secured Notes Balance Of Indenture Note To Common Stock [Member] | Reverse Recapitalization [Member]
Debt Details [Line Items]
Debt conversion converted instrument shares issued	882,318
Conversion of Senior Secured Note principal and royalty rights for common stock value	$ 5,000,000
Additional Principal Senior Secured Notes Balance Of Second Indenture Note to Common Stock [Member] | Reverse Recapitalization [Member]
Debt Details [Line Items]
Conversion of Senior Secured Note principal and royalty rights for common stock value	$ 3,600,000
Senior Notes [Member]
Debt Details [Line Items]
PIK and Indenture Note Principal					$ 3,600,000				3,600,000			3,600,000
Cash balance requirement								$ 10,000,000						10,000,000
Senior Secured Notes Holders Royality Obligation [Member]
Debt Details [Line Items]
Interest expense debt									700,000	600,000		2,200,000	1,400,000
Senior Secured Notes [Member]
Debt Details [Line Items]
Cash interest payments									$ 0	$ 0		$ 0	$ 0
Forbearance Agreement [Member]
Debt Details [Line Items]
Interest rate					18.50%		14.50%		18.50%			18.50%
Cash balance requirement														$ 2,500,000
Interest due amount							$ 3,100,000					$ 2,500
Minimum [Member]
Debt Details [Line Items]
Royalty on net sale												0.56%		0.56%
Maximum [Member]
Debt Details [Line Items]
Royalty on net sale												1.67%		1.67%
Convertible Notes Payable [Member]
Debt Details [Line Items]
Accrue interest rate												8.00%
Debt conversion converted instrument shares issued												8,529,846
Convertible Debt					$ 0				$ 0			$ 0
PIK Note [Member]
Debt Details [Line Items]
Borrowings amount											$ 3,100,000
PIK and Indenture Note Principal					$ 8,100,000				$ 8,100,000			$ 8,100,000
Interest rate																14.50%
Accrued and unpaid interest				$ 3,100,000
Indenture Note [Member]
Debt Details [Line Items]
Borrowings amount						$ 5,000,000
Interest rate					14.50%				14.50%			14.50%
Paycheck Protection Program Loan [Member]
Debt Details [Line Items]
Unsecured loan																		$ 500,000	$ 500,000
Convertible Debt [Member]
Debt Details [Line Items]
Borrowings amount														$ 61,300,000
Second Indenture Note [Member]
Debt Details [Line Items]
Borrowings amount												$ 3,600,000
Interest rate					14.50%				14.50%			14.50%
Series D Preferred Stock [Member]
Debt Details [Line Items]
Debt instrument, convertible conversion price														$ 4.50
Series D Preferred Stock [Member] | Convertible Notes Payable [Member] | Conversion of Principal and Accrued Interest Of Convertible Notes [Member]
Debt Details [Line Items]
Debt conversion converted instrument shares issued												747,451
Debt Conversion portion of debt converted												$ 3,400,000
Series D Preferred Stock [Member] | Convertible Notes Payable [Member] | Conversion of Principal Portion Of Convertible Notes [Member]
Debt Details [Line Items]
Debt Conversion portion of debt converted												2,600,000
Series D Preferred Stock [Member] | Convertible Notes Payable [Member] | Conversion of Accrued Interest Portion Of Convertible Notes [Member]
Debt Details [Line Items]
Debt Conversion portion of debt converted												$ 800,000

Debt (Details) - Schedule of co

Debt (Details) - Schedule of convertible notes outstanding $ in Thousands	Dec. 31, 2020USD ($)
Schedule Of Convertible Notes Outstanding [Abstract]
2016	$ 18,000
2017	14,000
2018	9,300
2019	18,389
2020	1,611
Total	$ 61,300

Debt (Details) - Schedule of ca

Debt (Details) - Schedule of carrying value convertible notes consisted - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Carrying Value Convertible Notes Consisted [Abstract]
Principal amount	$ 61,300	$ 59,689
Accrued and unpaid interest	17,287	11,230
Unamortized debt discount	(676)
Total	$ 77,911	$ 70,919

Debt (Details) - Schedule of se

Debt (Details) - Schedule of senior secured notes - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Details Schedule Of Senior Secured Notes [Line Items]
Principal amount		$ 61,300	$ 59,689
Accrued and unpaid interest		17,287	$ 11,230
Unamortized debt discount		(676)
Senior Secured Notes [Member]
Debt Details Schedule Of Senior Secured Notes [Line Items]
Principal amount	$ 43,125	50,000
Accrued and unpaid interest	1,234	1,278
Unamortized debt discount	(8,062)	(9,376)
Total	$ 40,339	$ 41,902

Debt (Details) - Schedule of fu

Debt (Details) - Schedule of future principal payments of the senior secured notes - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Future Principal Payments Of The Senior Secured Notes [Abstract]
2021 (remaining 3 months)	$ 0	$ 0
2022	6,000	7,500
2023	15,125	15,000
2024	14,000	17,500
2025	8,000	10,000
Total	$ 43,125	$ 50,000

Debt (Details) - Schedule of _2

Debt (Details) - Schedule of carrying value of the Company's royalty obligation $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Schedule Of Carrying Value Of The CompanyS Royalty Obligation [Abstract]
Royalty obligation as of December 31, 2020	$ 7,211
Non-cash interest expense recognized	2,051
Royalty obligation - ending balance	$ 9,262

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 17, 2020	Dec. 31, 2019
Stockholders' Equity (Details) [Line Items]
Common stock, shares authorized	125,000,000	56,593,539
Common stock, par value (in Dollars per share)	$ 0.0001	$ 0.001		$ 0.001
Common stock, shares issued		42,105,076		42,404,286
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value (in Dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0		0
Shares issued in exchange for cancellation of issued and outstanding series D convertible preferred stock	4,901,564
Common stock voting rights	one
Dividends, Common Stock	$ 0
Amended And Restated Certificate Of Incorporation [Member]
Stockholders' Equity (Details) [Line Items]
Common stock, shares authorized	125,000,000
Common stock, par value (in Dollars per share)	$ 0.0001
Common stock, shares issued	21,725,817
Common stock, shares outstanding	21,725,817
Preferred stock, shares authorized	10,000,000
Preferred stock, par value (in Dollars per share)	$ 0.0001
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0

Redeemable Convertible Prefer_3

Redeemable Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Redeemable Convertible Preferred Stock Details [Line Items]
Accrued and unpaid dividends (in Dollars)	$ 14.7	$ 13.6
Convertible into common stock, percentage	65.00%
Percentage of cumulative dividend	8.00%
Preferred shares outstanding percentage	65.00%
Series D Preferred Stock [Member]
Redeemable Convertible Preferred Stock Details [Line Items]
Purchase price (in Dollars per share)	$ 4.50	$ 4.50
Number of director	1
Series A Preferred Stock [Member]
Redeemable Convertible Preferred Stock Details [Line Items]
Purchase price (in Dollars per share)	$ 1.82
Series B Preferred Stock [Member]
Redeemable Convertible Preferred Stock Details [Line Items]
Purchase price (in Dollars per share)	1.82
Series C Preferred Stock [Member]
Redeemable Convertible Preferred Stock Details [Line Items]
Purchase price (in Dollars per share)	$ 1.50
Number of director	3

Redeemable Convertible Prefer_4

Redeemable Convertible Preferred Stock (Details) - Schedule of redeemable convertible preferred stock - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Preferred Stock Authorized	53,340,636	53,340,636
Preferred Stock Issued and Outstanding	36,756,498	36,756,498
Carrying Value (in Dollars)	$ 198,195	$ 183,513
Liquidation Value (in Dollars)	$ 198,195	$ 183,513
Common Stock Issuable Upon Conversion	36,756,498	36,756,498
Series A Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock Authorized	2,500,000	2,500,000
Preferred Stock Issued and Outstanding	2,500,000	2,500,000
Carrying Value (in Dollars)	$ 9,170	$ 8,491
Liquidation Value (in Dollars)	$ 9,170	$ 8,491
Common Stock Issuable Upon Conversion	2,500,000	2,500,000
Series B Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock Authorized	5,066,637	5,066,637
Preferred Stock Issued and Outstanding	5,066,637	5,066,637
Carrying Value (in Dollars)	$ 15,118	$ 13,998
Liquidation Value (in Dollars)	$ 15,118	$ 13,998
Common Stock Issuable Upon Conversion	5,066,637	5,066,637
Series C Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock Authorized	9,438,744	9,438,744
Preferred Stock Issued and Outstanding	9,438,744	9,438,744
Carrying Value (in Dollars)	$ 20,057	$ 18,571
Liquidation Value (in Dollars)	$ 20,057	$ 18,571
Common Stock Issuable Upon Conversion	9,438,744	9,438,744
Series D Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock Authorized	36,335,255	36,335,255
Preferred Stock Issued and Outstanding	19,751,117	19,751,117
Carrying Value (in Dollars)	$ 153,850	$ 142,453
Liquidation Value (in Dollars)	$ 153,850	$ 142,453
Common Stock Issuable Upon Conversion	19,751,117	19,751,117

Common Stock (Details)

Common Stock (Details) - $ / shares	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Common Stock [Abstract]
Common stock, shares authorized	125,000,000	56,593,539
Common stock par value	$ 0.0001	$ 0.001	$ 0.001

Common Stock (Details) - Schedu

Common Stock (Details) - Schedule of common stock for the potential conversion of outstanding preferred stock and exercise of stock options - shares	Dec. 31, 2020	Dec. 31, 2019
Common Stock (Details) - Schedule of common stock for the potential conversion of outstanding preferred stock and exercise of stock options [Line Items]
Total	42,105,076	42,404,286
Preferred stock, as converted [Member]
Common Stock (Details) - Schedule of common stock for the potential conversion of outstanding preferred stock and exercise of stock options [Line Items]
Total	36,756,498	36,756,498
Options to purchase common stock
Common Stock (Details) - Schedule of common stock for the potential conversion of outstanding preferred stock and exercise of stock options [Line Items]
Total	3,814,659	2,307,640
Series D warrants
Common Stock (Details) - Schedule of common stock for the potential conversion of outstanding preferred stock and exercise of stock options [Line Items]
Total	183,438	183,438
Remaining shares reserved for future issuance [Member]
Common Stock (Details) - Schedule of common stock for the potential conversion of outstanding preferred stock and exercise of stock options [Line Items]
Total	1,350,481	3,156,710

Stock Based Compensation (Detai

Stock Based Compensation (Details) - USD ($)	1 Months Ended		9 Months Ended	12 Months Ended
	Feb. 13, 2014	Jan. 28, 2011	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Aug. 27, 2021	Aug. 12, 2021	Dec. 18, 2020	Apr. 17, 2019	Dec. 15, 2017
Stock Based Compensation (Details) [Line Items]
Common stock, issued			21,725,817	4,901,564
Stock options contractual terms				5 years 1 month 6 days
Number of options Granted				1,806,229
Stock option [Member]
Stock Based Compensation (Details) [Line Items]
Stock options vested (in Dollars)				$ 800,000	$ 400,000
Unrecognized stock based compensation expense (in Dollars)				$ 600,000
Vesting period				1 year 1 month 20 days
Weighted average grant-date fair value of stock options granted (in Dollars per share)				$ 1.26	$ 1.59
Investment Owned, Unrecognized Unrealized Appreciation				$ 600,000
Stock incentive plan 2004 [Member]
Stock Based Compensation (Details) [Line Items]
Common stock, issued		1,529,936
Exercise price of incentive stock option		100.00%
Stock options contractual terms			10 years	10 years
2014 Stock Option and Incentive Plan [Member]
Stock Based Compensation (Details) [Line Items]
Common stock, issued	1,000,000
Additional federal tax requirements (in Dollars)	$ 100,000
Common stock reserved for issuance								3,000,000	26,140	416,500
Common stock available for award			4,442,640	4,442,640
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term			10 years	10 days
2021 Stock Option and Incentive Plan [Member]
Stock Based Compensation (Details) [Line Items]
Common stock reserved for issuance						3,475,000
Number of shares issued under plan			0
Threshold Annual Increase In Shares Reserved and Available For Issuance Percentage Of The Outstanding Number Of Shares Of Common Stock Of New Clarus						4.00%
2021 Stock Option and Incentive Plan [Member] | Stock option [Member]
Stock Based Compensation (Details) [Line Items]
Unrecognized stock based compensation expense (in Dollars)			$ 0
Investment Owned, Unrecognized Unrealized Appreciation			$ 0
Number of options Granted			0
Employee Stock Purchase Plan [Member]
Stock Based Compensation (Details) [Line Items]
Common stock reserved for issuance							347,500
Number of shares issued under plan			0
Threshold annual increase in shares reserved and available for issuance by minimum number of shares of common sock of new clarus							347,500
Threshold Annual Increase In Shares Reserved and Available For Issuance Percentage Of The Outstanding Number Of Shares Of Common Stock Of New Clarus							1.00%
Old 2004 And 2014 Plan [Member]
Stock Based Compensation (Details) [Line Items]
Share based payment arrangement,Expense recognized which is previously unrecognised stock based compensation related to unvested stock options			$ 200,000

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - Schedule of weighted-average assumptions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule of weighted-average assumptions [Abstract]
Expected volatility	59.66%	58.13%
Weighted-average risk-free interest rate	1.59%	2.58%
Expected dividend yield	0.00%	0.00%
Expected term (in years)	4 years	4 years

Stock Based Compensation (Det_2

Stock Based Compensation (Details) - Schedule of stock-based compensation expense - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 207	$ 90	$ 559	$ 234	$ 825	$ 359
Selling and marketing [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	6		15		183
Research and development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	19	15	52	54	189	108
General and administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 182	$ 75	$ 491	$ 180	$ 453	$ 251

Stock Based Compensation (Det_3

Stock Based Compensation (Details) - Schedule of stock option activity under the Plans	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Schedule Of Stock Option Activity Under The Plans [Abstract]
Number of options Outstanding | shares	2,307,640
Weighted average exercise price Outstanding | $ / shares	$ 1.70
Weighted average remaining contractual life (years) Outstanding	5 years 1 month 6 days
Aggregate intrinsic value Outstanding | $
Number of options Granted | shares	1,806,229
Weighted average exercise price Granted | $ / shares	$ 2.69
Number of options Cancelled | shares	(142,500)
Weighted average exercise price Cancelled | $ / shares	$ 1.49
Number of options Forfeited | shares	(156,710)
Weighted average exercise price Forfeited | $ / shares	$ 1.98
Number of options Outstanding | shares	3,814,659
Weighted average exercise price Outstanding | $ / shares	$ 2.17
Weighted average remaining contractual life (years) Outstanding	6 years 9 months 18 days
Aggregate intrinsic value Outstanding | $
Number of options Options vested and exercisable | shares	2,320,686
Weighted average exercise price Options vested and exercisable | $ / shares	$ 1.86
Weighted average remaining contractual life (years) Options vested and exercisable	6 years 10 months 24 days
Aggregate intrinsic value Options vested and exercisable | $

Income Taxes (Details)

Income Taxes (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Income Taxes Details LineItems [Line Items]
Federal net operating loss	$ 189.2
State net operating loss	169.1
Federal tax	134.9
State tax	$ 124.1
Deduction percentage	80.00%
U.S. federal [Member]
Income Taxes Details LineItems [Line Items]
Federal net operating loss	$ 54.4
Federal tax	6.7
U.S State [Member]
Income Taxes Details LineItems [Line Items]
State net operating loss	45
State tax	$ 0.1

Income Taxes (Details) - Schedu

Income Taxes (Details) - Schedule of net deferred tax assets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Stock compensation	$ 64	$ 12
Accruals and other	4,151	1,060
Debt discount	483	0
Royalty liability	2,272	0
Net operating loss carryforwards	51,918	44,641
Tax credits	6,774	6,774
Total deferred tax assets	65,662	52,487
Valuation Allowance	(65,662)	(52,487)
Deferred tax assets, net	$ 0	$ 0

Income Taxes (Details) - Sche_2

Income Taxes (Details) - Schedule of effective income tax rate - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule of effective income tax rate [Abstract]
Income at U.S. statutory rate	$ 912	$ (8,746)
Income at U.S. statutory rate, percentage	21.00%	21.00%
State taxes, net of federal benefit	$ (1,583)	$ (1,171)
State taxes, net of federal benefit, percentage	(36.45%)	2.81%
Change in fair value	$ (14,047)	$ 0
Change in fair value, percentage	(323.39%)	0.00%
Interest expense	$ 1,410	$ 5,009
Interest expense, percentage	32.46%	(12.03%)
Stock compensation	$ 127	$ 1,139
Stock compensation, percentage	2.93%	(2.73%)
Permanent differences	$ 6	$ 3
Permanent differences, percentage	0.13%	(0.01%)
Valuation allowance	$ 13,175	$ 3,561
Valuation allowance, percentage	303.32%	(8.55%)
Other	$ 0	$ 205
Other, percentage	0.00%	(0.49%)
Income tax rate	$ 0	$ 0
Income tax rate, percentage	0.00%	0.00%

Income Taxes (Details) - Sche_3

Income Taxes (Details) - Schedule of company's valuation allowance - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule Of CompanyS Valuation Allowance [Abstract]
Valuation allowance at beginning of year	$ 52,487	$ 48,926
Increases recorded to income tax provision	13,175	3,561
Valuation allowance at the end of year	$ 65,662	$ 52,487

License Agreements (Details)

License Agreements (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
License Agreements (Details) [Line Items]
Royalty payments	$ 24.2	$ 24.2
HavaH [Member]
License Agreements (Details) [Line Items]
Potential development and regulatory milestone payments	10.8
Royalty payments	30
Cash payments	0.5
McGill [Member]
License Agreements (Details) [Line Items]
Potential development and regulatory milestone payments	10.5
Royalty payments	15
Cash payments	$ 0.4

Commitments & Contingencies (De

Commitments & Contingencies (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 31, 2021	Jul. 31, 2009	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies [Line Items]
Settlement agreement description	In July 2021, Old Clarus and Lipocine entered into a settlement agreement that settled all claims between the parties, including the interference matter (described above) and the pending Old Clarus counterclaims against Lipocine, and provides for a payment by Lipocine to Old Clarus of a $4.0 million settlement fee payable as follows: $2.5 million upfront, $1.0 million within 12 months, and the remainder within two years. The Company is recognizing the payments in income as they are received. The Company received payment of $2.5 million of the $4.0 million in July 2021, which is recorded within the litigation settlement line in other income and expense on the statement of operations.
Catalent Pharma Solutions L L C [Member]
Commitments And Contingencies [Line Items]
Annual Purchases		7
Lease Agreements [Member]
Commitments And Contingencies [Line Items]
Rent Expense					$ 0.1	$ 0.1	$ 0.2	$ 0.1
Catalent Agreement [Member]
Commitments And Contingencies [Line Items]
Purchase Amount			$ 0.9	$ 0.1	$ 6	$ 3.1	$ 3.2	$ 5.8
Pfizer Agreement [Member]
Commitments And Contingencies [Line Items]
Annual Purchases					1.8		1.8

Commitments and Contingencies (

Commitments and Contingencies (Details) - Schedule of lease payments under non-cancellable lease agreements - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2021	$ 24	$ 95
2022	16	16
2023
2024
2025
Total	$ 40	$ 111

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Details) - $ / shares		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
NetIncome Loss Per Share Details [Line Items]
Effect of convertible notes (in Shares)	[1]	0	16,927,006	0	16,927,006
Series D Preferred Stock [Member]
NetIncome Loss Per Share Details [Line Items]
Shares Issued, Price Per Share						$ 4.50	$ 4.50
[1]	The effect of convertible notes on the denominator for the three and nine months ended September 30, 2020 was calculated based on the carrying value of the convertible notes balance at September 30, 2020, converted at the series D price of $4.50 per share and are added back to the denominator when calculating diluted EPS using the if-converted method.

Net Income (Loss) Per Share (_2

Net Income (Loss) Per Share (Details) - Schedule of basic and diluted earnings (loss) per share attributable to common stockholders - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss (income)		$ (2,769)	$ 5,406	$ (36,315)	$ 4,067	$ 4,345	$ (41,650)
Earnings attributable to Old Clarus participating warrants	[1]	0	(10)	0	(8)
Gain on extinguishment of convertible notes	[2]	412	0	412	0
Net (loss) income attributable to common stockholders, basic		(2,357)	5,396	(35,903)	(4,059)
Effect of convertible notes	[3]	0	(19,139)	0	(48,338)
Net loss attributable to common stockholders, diluted		$ (2,357)	$ (13,743)	$ (35,903)	$ (44,279)
Weighted-average common shares attributable to common stockholders, basic		9,153,848	4,901,564	6,318,992	4,901,564
Effect of convertible notes	[4]	0	16,927,006	0	16,927,006
Weighted average number of common shares - diluted		9,153,848	21,828,570	6,318,992	21,828,570
Net loss per common share attributable to common stockholders, basic		$ (0.26)	$ 1.10	$ (5.68)	$ 0.83
Effect of convertible notes		0	(1.73)	0	(2.86)
Net loss per common share attributable to common stockholders, diluted		$ (0.26)	$ (0.63)	$ (5.68)	$ (2.03)
[1]	The loss attributable to Old Clarus participating warrants relates to the total earnings attributable to the 9,246 Old Clarus participating warrants using the two-class method.
[2]	The gain on extinguishment of convertible notes relates to the difference between the carrying value of the convertible notes upon conversion to shares and the fair value of the shares exchanged which requires adjustment to the numerator when calculating basic EPS.
[3]	The effect of the convertible notes on the numerator for the three and nine months ended September 30, 2020 relates to the impact that the convertible notes had on net income during the period, and are removed from net income when calculating net income (loss) attributable to common stockholders diluted using the if-converted method.
[4]	The effect of convertible notes on the denominator for the three and nine months ended September 30, 2020 was calculated based on the carrying value of the convertible notes balance at September 30, 2020, converted at the series D price of $4.50 per share and are added back to the denominator when calculating diluted EPS using the if-converted method.

Net Income (Loss) Per Share (_3

Net Income (Loss) Per Share (Details) - Schedule of basic and diluted earnings (loss) per share attributable to common stockholders (Parenthetical)	Sep. 30, 2021USD ($)shares
Series D Preferred Stock [Member]
Convertible Notes Payable | $	$ 4.50
Old Clarus Warrants [Member]
Class of Warrant or Right, Outstanding | shares	9,246

Net Income (Loss) Per Share (_4

Net Income (Loss) Per Share (Details) - Schedule of computation of diluted net loss per share attributable to common stockholders - shares		3 Months Ended	9 Months Ended	12 Months Ended
		Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Old Clarus Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		9,246	9,246
Convertible notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	[1]			17,313,456	15,759,821
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares				3,814,659	2,307,640
Series D warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares				183,438	183,438
Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares				36,756,497	36,756,497
[1]	Convertible note shares are calculated using the Series D Preferred Stock issue price of $4.50 per share and includes interest accrued as of December 31, 2020 and 2019.

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Related Party Transactions (Details) [Line Items]
Consulting Fees	$ 0.2	$ 0.1

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Aggregate investors	$ 12.5
Accrued Interest Rate		8.00%
Receive Proceeds Net		$ 198.2
Noteholders Agreed Additional Capital		$ 25
Common Stock Price Per Share		$ 10
Maturity Date		Sep. 1, 2025

Business Combination - Summary

Business Combination - Summary Of Net Proceeds From The Business Combination (Details) - Business Combination [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Business Acquisition [Line Items]
Cash – Blue Water Trust Account and cash (net of redemptions)	$ 25,394
Less: Equity issuance costs and other costs paid prior to September 30, 2021	(8,386)
Net Proceeds from the Business Combination	$ 17,008

Business Combination - Summar_2

Business Combination - Summary Of Common Stock Issued In Consummation Of Business Combination (Details)	9 Months Ended
	Sep. 30, 2021shares
Blue Water shares outstanding prior to the Business Combination
Blue Water shares outstanding prior to the Business Combination	4,901,564
Total shares of the Company's common stock outstanding immediately following the Business Combination	21,725,817
Business Combination [Member]
Blue Water shares outstanding prior to the Business Combination
Blue Water shares outstanding prior to the Business Combination	3,839,468
Conversion of Old Clarus convertible notes	8,529,846
Conversion of additional capital provided by Old Clarus convertible note and senior note holders	2,549,939
Conversion of Senior Secured Note principal and royalty rights for common stock	1,905,000
Total shares of the Company's common stock outstanding immediately following the Business Combination	21,725,817
Business Combination [Member] | Series D Preferred Stock [Member]
Blue Water shares outstanding prior to the Business Combination
Conversion of Old Clarus Series D Preferred Stock	4,901,564

Business Combination - Summar_3

Business Combination - Summary of Impact of the transaction on the condensed consolidated statement of stockholder's equity (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Business Acquisition [Line Items]
Total reverse recapitalization impact on statement of equity	$ 117,513
Additional Paid-in Capital [Member]
Business Acquisition [Line Items]
Total reverse recapitalization impact on statement of equity	$ 117,512
Additional Paid-in Capital [Member] | Business Combination [Member] | Reverse Recapitalization Event [Member]
Business Acquisition [Line Items]
Conversion of senior notes and royalty obligation carrying value		$ 28,254
Conversion of Old Clarus convertible notes carrying value		103,333
Assumption of warrant liabilities		(14,075)
Total reverse recapitalization impact on statement of equity		$ 117,512

Business Combination (Details)

Business Combination (Details) - USD ($)	Sep. 09, 2021	Sep. 30, 2021	Dec. 31, 2020
Stock issued during period value new issues			$ (14,682,000)
Common stock, shares reallocated to the senior secured note holders from Old Clarus's equity holders		405,000
Business Combination [Member]
Conversion of Senior Secured Note principal and royalty rights for common stock		1,905,000
Business acquisation equity issuance costs and other costs	$ 8,400
Stock issued during period, Shares, Conversion of convertible securities		8,529,846
Business Combination [Member] | Reverse Recapitalization Event [Member]
Common Stock Shares allocated to Senior Secured Noteholders pursuant to the Share Allocation agreement		405,000
Common stock, shares reallocated to the senior secured note holders from Old Clarus's equity holders		270,000
Reverse Recapitalization [Member]
Conversion of Senior Secured Note principal and royalty rights for common stock	1,500,000
Reverse Recapitalization [Member] | Business Combination [Member]
Aggregate consideration issued or reserved for issuance at merger close	17,886,349
Conversion of Senior Secured Note principal and royalty rights for common stock	1,905,000	135,000
Conversion of Senior Secured Note principal and royalty rights for common stock value	$ 18,600
Private Placement [Member] | Reverse Recapitalization [Member] | Business Combination [Member]
Stock issued during period shares new issues	2,549,939
Exercise price	$ 10
Stock issued during period value new issues	$ 25,000
Series D Preferred Stock [Member] | Business Combination [Member] | Reverse Recapitalization Event [Member]
Conversion stock, shares issued (in Shares)	4,901,564
Stock issued during period, Shares, Conversion of convertible securities	8,529,846