MoonLake Immunotherapeutics (MLTX) POS AM 20 Mar 23 2022 FY Prospectus update (post-effective amendment) Financial data

Cover

Cover	12 Months Ended
	Dec. 31, 2022
Cover [Abstract]
Document Type	POS AM
Amendment Description	This Post-Effective Amendment No. 1 to Form S-1 (the “Post-Effective Amendment”) is being filed in order to update certain disclosures in the registration statement. Substantially concurrently with the filing of this Post-Effective Amendment, MoonLake Immunotherapeutics filed its Annual Report on Form 10-K.
Document Period End Date	Dec. 31, 2022
Entity Registrant Name	0001821586
Entity Filer Category	Non-accelerated Filer
Amendment Flag	true
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Entity Registrant Name	MOONLAKE IMMUNOTHERAPEUTICS

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 39,505,627	$ 8,038,845
Short-term marketable debt securities	32,609,108	0
Other receivables	217,129	148,774
Prepaid expenses	4,179,468	1,449,096
Total current assets	76,511,332	9,636,715
Non-current assets
Operating lease right-of-use assets	282,580	0
Property and equipment, net	49,389	45,739
Total non-current assets	331,969	45,739
Total assets	76,843,301	9,682,454
Current liabilities
Trade and other payables	254,972	1,569,290
Short-term portion of operating lease liabilities	153,629	0
Short-term loans	0	15,000,000
Accrued expenses and other current liabilities	7,256,845	4,518,311
Total current liabilities	7,665,446	21,087,601
Non-current liabilities
Long-term portion operating lease liability	128,951	0
Pension liability	282,206	239,860
Total non-current liabilities	411,157	239,860
Total liabilities	8,076,603	21,327,461
Commitments and contingencies (Note 16)
Equity (deficit)
Treasury Shares, 1,942,837 as of December 31, 2021	0	(6,202)
Additional paid-in capital	129,192,291	42,061,984
Accumulated deficit	(80,650,212)	(53,643,615)
Accumulated other comprehensive income (loss)	350,946	(168,177)
Total shareholders’ equity (deficit)	48,898,296	(11,645,007)
Noncontrolling interests	19,868,402	0
Total equity (deficit)	68,766,698	(11,645,007)
Total liabilities and equity (deficit)		9,682,454
Series A Preferred Shares
Equity (deficit)
Series A Preferred Shares, CHF 0.10 par value; 22,880,908 authorized; 22,880,908 shares issued and outstanding as of December 31, 2021 (liquidation preference of $33.4 million);	0	72,466
Common Shares
Equity (deficit)
Common Shares	0	38,537
Class A Ordinary Shares
Equity (deficit)
Common Shares	3,898	0
Class C Ordinary Shares
Equity (deficit)
Common Shares	$ 1,373	$ 0

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) $ in Millions	Dec. 31, 2021 USD ($) shares
Treasury Shares (in shares)	1,942,837
Series A Preferred Shares
Series A Preferred Shares, shares authorized (in shares)	22,880,908
Series A Preferred Shares, shares issued (in shares)	22,880,908
Series A Preferred Shares, shares outstanding (in shares)	22,880,908
Series A Preferred Shares, liquidation preference | $	$ 33.4
MoonLake AG Common Shares
Common shares, shares authorized (in shares)	13,119,092
Common Shares, shares issued (in shares)	12,161,331
Common Shares, shares outstanding (in shares)	10,218,495

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Operating expenses
Research and development	$ (35,529,331)	$ (42,048,954)
General and administrative	(18,047,681)	(23,012,463)
Total operating expenses	(53,577,012)	(65,061,417)
Operating loss	(53,577,012)	(65,061,417)
Other income (expense), net	(61,848)	591,732
Loss before income tax	(53,638,860)	(64,469,685)
Income tax expense	(4,755)	(36,366)
Net loss	(53,643,615)	(64,506,051)
Of which: net loss attributable to controlling interests shareholders	(53,643,615)	(49,973,249)
Of which: net loss attributable to noncontrolling interests shareholders	0	(14,532,802)
Net unrealized gain on marketable securities and short-term investments	0	390,753
Actuarial income (loss) on employee benefit plans	(168,177)	269,893
Other comprehensive income (loss)	(168,177)	660,646
Comprehensive loss	(53,811,792)	(63,845,405)
Comprehensive loss attributable to controlling interests shareholders	(53,811,792)	(49,437,461)
Comprehensive loss attributable to noncontrolling interests	$ 0	$ (14,407,944)
Weighted-average number of shares, basic (in shares)	7,840,707	29,361,353
Weighted-average number of shares, diluted (in shares)	7,840,707	29,361,353
Basic net loss per share attributable to controlling interest shareholders (USD per share)	$ (6.84)	$ (1.70)
Diluted net loss per share attributable to controlling interest shareholders (USD per share)	$ (6.84)	$ (1.70)
Class A Ordinary Shares
Operating expenses
Weighted-average number of shares, basic (in shares)	0	29,361,353
Weighted-average number of shares, diluted (in shares)	0	29,361,353
Basic net loss per share attributable to controlling interest shareholders (USD per share)	$ 0	$ (1.70)
Diluted net loss per share attributable to controlling interest shareholders (USD per share)	$ 0	$ (1.70)
MoonLake AG Common Shares
Operating expenses
Weighted-average number of shares, basic (in shares)	7,840,707	0
Weighted-average number of shares, diluted (in shares)	7,840,707	0
Basic net loss per share attributable to controlling interest shareholders (USD per share)	$ (6.84)	$ 0
Diluted net loss per share attributable to controlling interest shareholders (USD per share)	$ (6.84)	$ 0

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (DEFICIT) - USD ($)	Total	Conversion Following Business Combination	Class A Ordinary Shares	Class C Ordinary Shares	Previously Reported	Total Shareholders' Equity (Deficit)	Total Shareholders' Equity (Deficit) Conversion Following Business Combination	Total Shareholders' Equity (Deficit) Conversion Of Class C Into Class A Shares	Total Shareholders' Equity (Deficit) Previously Reported	MoonLake AG Series A Preferred Shares	MoonLake AG Series A Preferred Shares Conversion Following Business Combination	MoonLake AG Series A Preferred Shares Previously Reported	MoonLake AG Series A Preferred Shares Revision of Prior Period, Adjustment	MoonLake AG Common Shares	MoonLake AG Common Shares Conversion Following Business Combination	MoonLake AG Common Shares Class A Ordinary Shares	MoonLake AG Common Shares Class A Ordinary Shares Conversion Following Business Combination	MoonLake AG Common Shares Class A Ordinary Shares Conversion Of Class C Into Class A Shares	MoonLake AG Common Shares Class C Ordinary Shares	MoonLake AG Common Shares Class C Ordinary Shares Conversion Following Business Combination	MoonLake AG Common Shares Class C Ordinary Shares Conversion Of Class C Into Class A Shares	MoonLake AG Common Shares Previously Reported	MoonLake AG Common Shares Revision of Prior Period, Adjustment	MoonLake AG Common Shares Held In Treasury	MoonLake AG Common Shares Held In Treasury Conversion Following Business Combination	MoonLake AG Common Shares Held In Treasury Previously Reported	MoonLake AG Common Shares Held In Treasury Revision of Prior Period, Adjustment	Additional Paid-In Capital	Additional Paid-In Capital Conversion Following Business Combination	Additional Paid-In Capital Conversion Of Class C Into Class A Shares	Additional Paid-In Capital Previously Reported	Accumulated Deficit	Accumulated Deficit Previously Reported	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Conversion Of Class C Into Class A Shares	Accumulated Other Comprehensive Income (Loss) Previously Reported	Noncontrolling Interests	Noncontrolling Interests Conversion Of Class C Into Class A Shares
Common stock, beginning balance (in shares) at Mar. 09, 2021														33,638,698								1,000,000	32,638,698
Equity, beginning balance at Mar. 09, 2021	$ 106,507				$ 106,507	$ 106,507			$ 106,507					$ 106,507								$ 106,507
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense through transfer of existing Common shares (3,330,231) to Merck KGaA, Darmstadt, Germany, and conversion of transferred shares into Series A Preferred shares (in shares)	3,330,231									3,330,231				3,330,231
Share-based compensation expense through transfer of existing Common Shares (3,330,231) to Merck KGaA, Darmstadt, Germany, and conversion of transferred shares into Series A Preferred Shares	$ 4,851,000					4,851,000				$ 10,544				$ (10,544)														$ 4,851,000
Preferred Shares purchased by a director following his appointment as chairman of the Board of Directors (in shares)										342,980
Preferred Shares purchased by a director following his appointment as chairman of the Board of Directors	495,050					495,050				$ 1,106																		493,944
Emission Fee Reimbursement on Capital Increase	$ 4,894					4,894																						4,894
Conversion and transfer of shares between classes (in shares)	19,207,697									19,207,697				19,207,697
Conversion and transfer of shares between classes	$ 27,659,237					27,659,237				$ 60,816				$ (60,816)														27,659,237
Share-based compensation granted under the equity incentive plan ESPP, and reverse vesting of Restricted Founder Shares (in shares)														1,060,561
Share-based compensation granted under the equity incentive plan ESPP, and reverse vesting of Restricted Founder Shares	$ 9,056,299					9,056,299								$ 3,390														9,052,909
Repurchase of 1,942,837 Common Shares following the resignation of a co-founder (in shares)	(1,942,837)																							(1,942,837)
Repurchase of 1,942,837 Common Shares following the resignation of a co-founder	$ (6,202)					(6,202)																		$ (6,202)
Net loss	(53,643,615)					(53,643,615)																										$ (53,643,615)
Other comprehensive income (loss)	(168,177)					(168,177)																												$ (168,177)
Preferred stock, ending balance (in shares) at Dec. 31, 2021										22,880,908		680,196	22,200,712
Common stock, ending balance (in shares) at Dec. 31, 2021														12,161,331								361,528	11,799,803
Held in Treasury, ending balance (in shares) at Dec. 31, 2021																								(1,942,837)		(57,756)	(1,885,081)
Equity, end balance at Dec. 31, 2021	(11,645,007)				$ (11,645,007)	(11,645,007)			$ (11,645,007)	$ 72,466		$ 72,466		$ 38,537								$ 38,537		$ (6,202)		$ (6,202)		42,061,984			$ 42,061,984	(53,643,615)	$ (53,643,615)	(168,177)		$ (168,177)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Emission Fee Reimbursement on Capital Increase	$ (56,240)					(40,078)																						(40,078)									$ (16,162)
Noncontrolling interests recognized on historical net assets of MoonLake AG in connection with the Business Combination						8,346,506				$ (23,939)				$ (12,730)										$ 797				(14,551,870)				22,966,652		(32,404)			(8,346,506)
Conversion and transfer of shares between classes (in shares)											22,880,908				12,161,331		18,501,284	2,051,961		15,775,472	2,051,961				765,483
Conversion and transfer of shares between classes		$ 1,578					$ 1,578	$ 3,536,045			$ (48,527)				$ (25,807)		$ 1,850	$ 205		$ 1,578	$ (205)				$ 1,614				$ 70,870	$ 3,520,306					$ 15,739			$ (3,536,045)
Issuance of Class A ordinary shares upon business combination (in shares)	18,424,355															18,424,355
Issuance of Class A Ordinary Shares upon Business Combination	$ 134,653,204					90,783,936										$ 1,843												90,782,093									43,869,268
Share-based compensation granted under the equity incentive plan ESPP, and reverse vesting of Restricted Founder Shares (in shares)																								1,177,354
Share-based compensation granted under the equity incentive plan ESPP, and reverse vesting of Restricted Founder Shares	9,658,568					7,352,777																		$ 3,791				$ 7,348,986									2,305,791
Net loss	(64,506,051)					(49,973,249)																										$ (49,973,249)					(14,532,802)
Other comprehensive income (loss)	660,646					$ 535,788																												$ 535,788			$ 124,858
Common stock, ending balance (in shares) at Dec. 31, 2022			38,977,600	13,723,511												38,977,600			13,723,511
Held in Treasury, ending balance (in shares) at Dec. 31, 2022																								0
Equity, end balance at Dec. 31, 2022	$ 68,766,698															$ 3,898			$ 1,373
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense through transfer of existing Common shares (3,330,231) to Merck KGaA, Darmstadt, Germany, and conversion of transferred shares into Series A Preferred shares (in shares)			36,925,639
Preferred Shares purchased by a director following his appointment as chairman of the Board of Directors (in shares)			11,700,000	15,775,472
Conversion and transfer of shares between classes (in shares)																			15,775,472
Issuance of Class A ordinary shares upon business combination (in shares)			18,501,284
Common stock, ending balance (in shares) at Apr. 05, 2022	52,701,111

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (DEFICIT) (Parenthetical)	10 Months Ended
	Dec. 31, 2021 USD ($) shares
Statement of Stockholders' Equity [Abstract]
Share-based compensation expense through transfer of existing Common shares (3,330,231) to Merck KGaA, Darmstadt, Germany, and conversion of transferred shares into Series A Preferred shares (in shares)	3,330,231
Conversion and transfer of shares between classes (in shares)	19,207,697
Issuance costs | $	$ 279,364
Repurchase of Common Shares following the resignation of a co-founder (in shares)	1,942,837

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Cash flow from operating activities
Net loss	$ (53,643,615)	$ (64,506,051)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	4,971	12,358
Share-based payment	9,052,909	9,654,778
Share-based compensation for the in-licensing agreement	4,851,000	0
Net periodic pension benefit cost for the qualified pension plan	71,685	304,031
Other non-cash items	3,635	68,454
Changes in operating assets and liabilities:
Other receivables	(148,774)	(68,355)
Prepaid expenses	(1,449,096)	(2,730,373)
Trade and other payables	1,569,290	(1,314,318)
Accrued expenses and other current liabilities	4,512,801	2,685,576
Net cash flow used in operating activities	(35,175,194)	(55,893,900)
Cash flow from investing activities
Purchase of short-term marketable debt securities	0	(42,226,021)
Proceeds from maturities of short-term marketable debt securities	0	9,901,437
Purchase of property and equipment	(50,710)	(16,009)
Net cash flow used in investing activities	(50,710)	(32,340,593)
Cash flow from financing activities
Issuance of Common Shares at incorporation	106,507	0
Issuance of Series A Preferred Shares, net	28,159,181	0
Proceeds from Business Combination	0	134,646,009
Contribution for par value of Class V Shares	0	42,935
Proceeds from short-term loans	15,000,000	0
Repayment of loan liability	0	(15,000,000)
Repurchase of treasury shares	(6,202)	0
Grants of additional shares under ESPP	3,390	3,791
Net cash flow provided by financing activities	43,262,876	119,692,735
Effect of movements in exchange rates on cash held	1,873	8,540
Net change in cash and cash equivalents	8,038,845	31,466,782
Cash and cash equivalents, beginning of period	0	8,038,845
Cash and cash equivalents, end of period	8,038,845	39,505,627
Supplemental Cash Flow Information [Abstract]
Cash paid for income taxes	0	4,312
Non-cash operating lease assets obtained in exchange for lease obligations	$ 0	$ 435,005

Overview of the Company

Overview of the Company	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview of the Company	Overview of the Company Corporate Information MoonLake Immunotherapeutics is a clinical-stage biotechnology company engaged in leveraging Nanobody® technology to develop next-level medicines for immunologic diseases, including inflammatory skin and joint diseases. MoonLake Immunotherapeutics focuses on developing its novel tri-specific Nanobody® Sonelokimab (“ SLK ”), an IL-17A and IL-17F inhibitor, in multiple inflammatory diseases in dermatology and rheumatology where the pathophysiology is known to be driven by IL-17A and IL-17F.

Business Combination Agreement

Business Combination Agreement with Helix and Recapitalization	12 Months Ended
	Dec. 31, 2022
Reverse Recapitalization [Abstract]
Business Combination Agreement with Helix and Recapitalization	Business Combination Agreement with Helix and Recapitalization On April 5, 2022 (the “ Closing Date ”), MoonLake Immunotherapeutics, a Cayman Islands exempted company (formerly known as Helix Acquisition Corp.) (prior to the Closing Date, “ Helix ” and after the Closing Date, “ MoonLake ” or the “ Company ”) consummated the previously announced business combination (the “ Closing ”) pursuant to that certain Business Combination Agreement dated October 4, 2021 (the “ Business Combination Agreemen t”), by and among Helix, MoonLake Immunotherapeutics AG, a Swiss stock corporation (Aktiengesellschaft) registered with the commercial register of the Canton of Zug, Switzerland under the number CHE-433.093.536 (“ MoonLake AG ”), the existing equity holders of MoonLake AG set forth on the signature pages to the Business Combination Agreement and the equityholders of MoonLake AG that executed joinders to the Business Combination Agreement (collectively, the “ ML Parties ”), Helix Holdings LLC, a Cayman Islands limited liability company and the sponsor of Helix (the “ Sponsor ”), and the representative of the ML Parties (such transactions contemplated by the Business Combination Agreement collectively, the “ Business Combination ”). Net proceeds from the Business Combination totaled $134.7 million, which included funds held in Helix’s trust account and the completion of a concurrent PIPE investment. Pursuant to the Business Combination Agreement, approved by the boards of directors of each of MoonLake AG and Helix, (i) the Company changed its name from Helix Acquisition Corp. to MoonLake Immunotherapeutics, and (ii) MoonLake AG merged with and into MoonLake, with MoonLake AG as the surviving company in the Business Combination and, after giving effect to such Business Combination, MoonLake AG as a subsidiary of MoonLake. The Business Combination Agreement provided for, among other things, the following transactions: i. Two business days prior to the Closing Date, the ML Parties and MoonLake AG effectuated a restructuring of MoonLake AG’s share capital to, among other things, (x) convert the Series A preferred shares of MoonLake AG, par value of CHF 0.10 per share, into an equal number of MoonLake AG Common Shares such that the ML Parties held a single class of capital share of MoonLake AG immediately prior to the Closing and (y) approve a capital increase for the issuance of 4,006,736 Class V Voting Shares of MoonLake AG, par value CHF 0.01 per share, to Helix, each Class V Voting Share due to its lower par value having ten times the voting power of a MoonLake AG Common Share (the “ Restructuring ”). ii. At the Closing, 2,875,000 Class B ordinary shares of Helix, par value $0.0001 per share (the “ Class B Ordinary Shares ”), constituting all of the then-outstanding Class B Ordinary Shares, were automatically converted into Class A Ordinary Shares on a one-for-one basis. iii. At the Closing, Helix amended and restated its existing memorandum and articles of association to, among other things, establish a share structure consisting of the Class A Ordinary Shares, which carry economic and voting rights, and Class C Ordinary Shares, which carry voting rights but no economic rights. iv. On the Closing Date, Helix paid all unpaid transaction expenses and contributed $134.7 million to MoonLake AG, including $15.0 million loan repayment pursuant to a convertible loan agreement dated March 20, 2022, by and between MoonLake AG and Cormorant Asset Management LP (“ Cormorant ”), and assigned by Cormorant to Helix on March 31, 2022. v. On the Closing Date, following the Restructuring, Biotechnology Value Fund, L.P., Biotechnology Value Fund II, L.P., and Biotechnology Value Trading Fund OS, L.P. (collectively, the “ BVF Shareholders ”) assigned all of their MoonLake AG Common Shares to Helix and Helix issued to the BVF Shareholders 18,501,284 Class A Ordinary Shares. vi. On the Closing Date, following the Restructuring, Helix issued 15,775,472 Class C Ordinary Shares to the ML Parties (other than the BVF Shareholders). Please refer to Note 12 — Shareholders’ Equity (Deficit) for additional details on the exchange mechanism adopted. Additionally, on the Closing Date, Helix issued to the PIPE Investors (as defined below in the section entitled “ PIPE Financing ”) an aggregate of 11,700,000 Class A Ordinary Shares. As of the open of trading on April 6, 2022, the Class A Ordinary Shares, formerly those of Helix, began trading on The Nasdaq Capital Market (“ Nasdaq ”) under the trading symbol “MLTX”. PIPE Financing On October 4, 2021, concurrently with the execution of the Business Combination Agreement, and subsequently on March 31, 2022 and April 4, 2022, Helix entered into subscription agreements with certain investors (collectively, the “ PIPE Investors ”, which includes affiliates of the Sponsor and certain existing equityholders of MoonLake AG) pursuant to which, and on the terms and subject to the conditions of which, the PIPE Investors have collectively subscribed for 11,700,000 Class A Ordinary Shares, 11,600,000 shares of which were issued at a price of $10.00 per share for gross proceeds of $116.0 million and 100,000 shares of which were issued to placement agents of the PIPE in satisfaction of an aggregate of $1.0 million of fees owed by Helix to such placement agents. Summary of Net Proceeds The following table summarizes the elements of the net proceeds from the Business Combination: in thousands Investments held in Trust Account $ 115,051 Less cash to cover redemptions of the Class A Ordinary Shares issued by Helix prior to the Closing Date (80,842) Plus PIPE investment 116,000 Less Helix transaction expense (15,520) of which accrued expenses (5,798) of which deferred IPO underwriting fee (4,025) of which other transaction expenses (5,697) Available Closing Date Cash $ 134,689 Summary of Ordinary Shares Issued The following table summarizes the number of Ordinary Shares outstanding immediately following the consummation of the Business Combination: Helix Acquisition Corp. Ordinary Shares prior to the Business Combination 14,805,000 Of which Class A Ordinary Shares (Helix management - IPO private placement shares) 430,000 Of which Class A Ordinary Shares redeemable 11,500,000 Of which Class B Ordinary Shares (Helix management - sponsor promote) 2,875,000 Less redemptions of the Class A Ordinary Shares issued by Helix prior to the Closing Date (8,080,645) Plus issuance of Helix Class A Ordinary Shares to PIPE Investors 11,700,000 Plus issuance of Helix Class A Ordinary Shares to BVF Shareholders 18,501,284 Total MoonLake Class A Ordinary Shares Outstanding at Closing 36,925,639 Plus issuance of Helix Class C Ordinary Shares to ML Parties (other than the BVF Shareholders) 15,775,472 Total MoonLake Class A and Class C Ordinary Shares Outstanding at Closing 52,701,111 Further information about the Business Combination can be found on Form S-1/A filed with the SEC on July 26, 2022, declared effective on August 2, 2022 and to the exhibits included therein, available at www.sec.gov.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements include those of the Company and its subsidiaries, MoonLake AG and MoonLake Immunotherapeutics Ltd., after elimination of all intercompany accounts and transactions. The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“ GAAP ”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ ASC ”) and Accounting Standards Updates (“ ASU ”) of the Financial Accounting Standards Board (“ FASB ”). Pursuant to ASC 805, for financial accounting and reporting purposes, MoonLake AG was deemed the accounting acquirer and Helix was treated as the accounting acquiree, and the Business Combination was accounted for as a reverse recapitalization. Accordingly, the Business Combination was treated as the equivalent of MoonLake AG issuing shares for the net assets of Helix, accompanied by a recapitalization. The net assets of Helix were stated at historical costs, with no goodwill or other intangible assets recorded, and are consolidated with MoonLake AG’s financial statements on the Closing Date. In accordance with the Business Combination Agreement, the ML Parties received 33.638698 Ordinary Shares in the Company for every MoonLake AG Common Share or Series A Preferred Share (the “ Exchange Ratio ”). The BVF Shareholders received 18,501,284 Class A Ordinary Shares whereas the rest of the ML Parties (excluding the BVF Shareholders) received 15,775,472 Class C Ordinary Shares which can be converted into Class A Ordinary Shares at the discretion of the shareholder (refer to Note 12 — Shareholders’ Equity (Deficit) for further details on the classes of ordinary shares). The number of shares, and the number of shares within the net income (loss) per share held by the ML Parties in MoonLake AG prior to the Business Combination have been adjusted by the Exchange Ratio to reflect the equivalent number of ordinary shares in the Company (identified as “ the equivalent of ” throughout these consolidated financial statements). Certain MoonLake AG shareholders (ML Parties other than the BVF Shareholders), did not exchange their shares in MoonLake AG for Class A Ordinary Shares in the Company and therefore continued to hold an economic interest in MoonLake AG and Class C Ordinary Shares in the Company. The Company recognized a noncontrolling interest equal to the ML Parties’ (other than the BVF Shareholders) proportionate interest in the net assets of MoonLake AG. All amounts are presented in U.S. Dollar (“ $ ”), unless otherwise indicated. The term “ Swiss franc ” and “ CHF ” refer to the legal currency of Switzerland, and “ € ” refers to Euros. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires the Company to make judgments, estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of expenses. The significant judgments, estimates and assumptions relevant to the Company relate to: • determining whether the in-process research and development expenditure (“ IPR&D ”) has an alternative future use; • estimating the fair value of the portion of the aggregate purchase price relating to its own shares in connection with the acquisition of the in-license agreement; • determining assumptions used in determining the fair value of share-based compensation; • estimating the recoverability of the deferred tax asset; and • estimating the amount of accruals in connection with the completion of clinical trial milestones. The Company bases its judgments and estimates on various factors and information, which may include, but are not limited to, the Company’s forecasts and future plans, current economic conditions and observable market-based transactions of its own shares, the results of which form the basis for making judgments about the carrying value of assets and liabilities and recorded amounts of expenses that are not readily apparent from other sources. To the extent there are material differences between the Company’s estimates and the actual results, the Company’s future results of operation may be affected. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value. As of December 31, 2022, the Company considers $19.9 million of short-term marketable debt securities in the form of eurocommercial papers to be cash equivalents. As of December 31, 2021, the Company did not have any cash equivalents. Marketable securities and short-term investments The Company invests in short-term marketable securities in the form of debt securities. At the time of purchase, the Company assesses whether such debt security should be classified as held-to-maturity or available-for-sale debt securities. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. Held-to-maturity debt securities are carried at amortized cost, adjusted for accretion of discounts or amortization of premiums to maturity computed under the effective interest method. Such accretion or amortization is included in “Interest and dividend income” Marketable debt securities not classified as held-to-maturity are classified as available-for-sale and reported at fair value. Net unrealized gains and losses on available-for-sale debt securities are excluded from the determination of earnings and are instead recognized in the “Accumulated other comprehensive income (loss)” component of shareholder’ equity (deficit) until realized. Realized gains and losses on available-for-sale debt securities are computed based upon the historical cost of these securities, using the specific identification method. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the security. Dividend and interest income are recognized when earned. Realized gains and losses are included in earnings and the cost of securities sold is determined using the specific-identification method. Marketable debt securities are classified as either “Cash and cash equivalents” or “Short‑term marketable debt securities” according to their original maturity at the time of acquisition. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash accounts in a large financial institution which, at times, may exceed the CHF 100,000 deposit protection limit. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash and cash equivalents are held. Further, the Company's investment strategy for cash (in excess of current business requirements) is set to invest in short-term securities. Management actively monitors credit risk in the investment portfolio. Credit risk exposures are controlled in accordance with policies approved by the board of directors to identify, measure, monitor and control credit risks. Fair Value Measurements The Company follows the guidance included in ASC 820, Fair Value Measurement. 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. There are three levels of inputs to fair value measurements: • Level 1, meaning the use of quoted prices for identical instruments in active markets; • Level 2, meaning the use of quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable; and • Level 3, meaning the use of unobservable inputs. Observable market data is used when available. Transfers between Levels 1, 2 or 3 within the fair value hierarchy are recognized at the end of the reporting period when the respective transaction occurred. Segment Information The Company operates as a single operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a stand-alone basis for the purposes of allocating resources, and assessing financial performance. Property and Equipment Property and equipment, net is stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method based on the estimated useful lives of three Research and Development Contract Costs and Accruals Research and development expenses include employee payroll, consulting, contract research and contract manufacturing costs attributable to research and development activities and are expensed as incurred. Upfront payments and milestone payments made for the licensing of technology are expensed as research and development expenses in the period in which it is probable that a liability has been incurred. Advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed. The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. Share-Based Transaction Goods or services received in a share-based payment transaction are measured using a fair value-based measure. Stock-Based Compensation The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to eligible employees, members of the board of directors and independent contractors that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgements about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s common stock on the date of the grant. For all stock options granted, the Company calculated the expected term as the period that share-based awards are expected to be outstanding. The estimate of expected volatility is based on comparative companies’ volatility within the Company's industry. The risk-free rate is based on the yield available on United States Treasury zero-coupon issues corresponding to the expected term of the award. The fair value of the common stock granted under the ESPP has historically been estimated by management with reference to the market-based transaction with the other Series A Preferred Shares Investors, as there was no public market for the common stock. Share-based payment arrangements are accounted for under the fair value method. Total compensation is measured at grant date, based on the fair value of the award at that date, and recorded in earnings over the period the employees are required to render service. The Company recognizes compensation cost only for those awards expected to meet the service conditions on a straight-line basis over the requisite service period of the award. Foreign Currency The functional currency of the Company and its subsidiaries is the U.S. dollar. Balances and transactions denominated in foreign currencies are converted as follows: monetary assets and liabilities are translated using exchange rates in effect at the balance sheet dates and non-monetary assets and liabilities are translated at historical exchange rates. Revenue and expenses are translated at the daily exchange rate on the respective accounting date. Gains or losses from foreign currency translation are included in the consolidated statement of operations. The Company recognized foreign currency transaction gain of $325,317 for the year ended December 31, 2022 (“the period ended December 31, 2022”) and a foreign currency transaction loss of $59,660 for the period ended December 31, 2021. Income Taxes The Company accounts for income taxes by using the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. A valuation allowance is recorded to the extent it is more likely than not that all or a portion of the Company's deferred tax assets will not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date. Net Loss per Class A Ordinary Shares Basic net loss per Class A Ordinary Share is calculated using the two-class method under which earnings are allocated to both Class A Ordinary Shares and participating securities. Basic net loss per share is calculated by dividing the net loss attributable to Class A Ordinary Shares by the weighted-average number of Class A Ordinary Shares outstanding for the period. The diluted net loss per Class A Ordinary Share is computed by dividing the net loss using the weighted-average number of Class A Ordinary Shares and, if dilutive, potential Class A Ordinary Shares outstanding during the period. In periods in which the Company reports a net loss attributable to shareholders of Class A Ordinary Shares, diluted net loss per share attributable to shareholders of Class A Ordinary Shares is the same as basic net loss per share attributable to shareholders of Class A Ordinary Shares, since dilutive Class A Ordinary Shares are not assumed to be outstanding if their effect is anti-dilutive. Acquisitions The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first assessing whether substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. The Company acquired the Sonelokimab program (the “ SLK Program ”) during the period ended December 31, 2021 and determined that substantially all of the fair value of the gross assets acquired related to IPR&D of SLK. Therefore, this transaction was accounted for as an asset acquisition. IPR&D represents incomplete technologies that the Company acquires, which at the time of acquisition, are still under development and have no alternative future use. The fair value of such technologies is expensed upon acquisition. A technology is considered to have an alternative future use if it is probable that the Company will use the asset in its current, incomplete state as it existed at the acquisition date, in another research and development project that has not yet commenced, and economic benefit is anticipated from that use. If a technology is determined to have an alternative future use, then the fair value of the program would be recorded as an asset on the balance sheet rather than expensed. Contingent consideration payments (for example milestone payments due upon the occurrence of a specific event) in asset acquisitions are recognized in the period in which it is probable that a liability has been incurred (unless the contingent consideration meets the definition of a derivative, in which case the amount becomes part of the cost in the asset acquired). Upon recognition of the contingent consideration payment, the amount is expensed if it relates to IPR&D or capitalized if it relates to a developed product which is generally considered to be when clinical trials have been completed and regulatory approval obtained. Future royalty payments due on net sales will be recognized in cost of goods sold when net sales are recognized. Pension Accounting The Company accounts for pension assets and liabilities in accordance with ASC 715, Compensation – Retirement Benefits, which requires the recognition of the funded status of pension plans in the Company’s consolidated balance sheet. The liability in respect to defined benefit pension plans is the projected benefit obligation calculated annually by independent actuaries using the projected unit credit method. The projected benefit obligation as of December 31, 2022 represents the actuarial present value of the estimated future payments required to settle the obligation that is attributable to employee services rendered before that date. Service costs for such pension plans, represented in the net periodic benefit cost, are included in the personnel expenses of the various functions where the employees are engaged. The other components of net benefit cost are included in the consolidated statement of operations separately from the service cost component, in “ other income (expenses), net Gains or losses arising from plan curtailments or settlements are accounted for at the time they occur. Any net pension asset is limited to the present value of the future economic benefits available to the Company in the form of refunds from the plan or expected reductions in future contributions to the plan. Actuarial gains and losses arising from differences between the actual and the expected return on plan assets are recognized in accumulated other comprehensive income (loss). Recently Adopted Accounting Pronouncements Leases In February 2016, the FASB issued ASU No. 2016-02, Leases Topic 842 (“ ASU 2016-02 ”) . The guidance in ASU 2016-02 supersedes the lease recognition requirements in ASC 840, Leases. ASU 2016-02 requires an entity to recognize assets and liabilities arising from a lease for both financing and operating leases, along with additional qualitative and quantitative disclosures. ASU 2016-02 is effective for fiscal years beginning after December 15, 2021, and for interim periods within fiscal years beginning after December 15, 2022, with early adoption permitted. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842) : Targeted Improvements, which allows entities to elect a modified retrospective transition method where entities may continue to apply the existing lease guidance during the comparative periods and apply the new lease requirements through a cumulative effect adjustment in the period of adoptions rather than in the earliest period presented. The Company determines if an arrangement is or contains a lease at contract inception. For these arrangements, it is evaluated if the arrangement involves an identified asset that is physically distinct or whether the Company has the right to substantially all of the capacity of an identified asset that is not physically distinct. In arrangements that involve an identified asset, there is also judgment in evaluating if the Company has the right to direct the use of that asset. MoonLake does not have any finance leases. The Company only has one operating lease related to the office space located in Dorfstrasse 29, 6300, Zug, Switzerland. The operating lease is recognized over a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property. Right-of-Use (“ RoU ”) assets and lease liabilities are measured at the lease commencement date based on the present value of the remaining lease payments over the lease term, determined using the discount rate for the lease at the commencement date. Because the rate implicit in the leases is not readily determinable, the Company uses the incremental borrowing rate as the discount rate, which approximates the interest rate at which the Company could borrow on a collateralized basis with similar terms and payments and in similar economic environments. Leases with an initial term of 12 months or less and that do not have the option to purchase the underlying asset are not recorded on the balance sheet, with lease expense for these leases recognized on a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property. Recently Issued Accounting Pronouncements not yet Adopted The Company is an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012 (“ JOBS Act ”). As such the Company is eligible for exemptions from various reporting requirements applicable to other public companies that are not emerging growth companies, including reduced reporting and extended transition periods to comply with new or revised accounting standards for public business entities. The Company has elected to avail itself of this exemption and, therefore, will not be subject to the timeline for adopting new or revised accounting standards for public business entities that are not emerging growth companies, and will follow the transition guidance applicable to private companies. Recently issued accounting pronouncements not yet adopted, that the Company plans to adopt, are not expected to have a material impact on the Company’s consolidated financial position, operating results, cash flows, or disclosures.

Risks and Liquidity

Risks and Liquidity	12 Months Ended
	Dec. 31, 2022
Risks and Uncertainties [Abstract]
Risks and Liquidity	Risks and Liquidity Going Concern, Liquidity and Capital Resources The Company incurred a loss of $64.5 million for the year ended December 31, 2022. As of December 31, 2022, the Company’s current assets exceeded its current liabilities by $68.8 million.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following table presents the Company’s short-term marketable debt securities by level within the fair value hierarchy: December 31, 2022 Level 1 Level 2 Level 3 Total Eurocommercial papers (1) $ — $ 42,552,608 $ — $ 42,552,608 Certificates of deposit — 9,937,899 — 9,937,899 Total $ — $ 52,490,507 $ — $ 52,490,507 _________________ (1) Eurocommercial papers in the amount of $19.9 million are classified as cash and cash equivalents. There were no Eurocommercial Papers, Certificates of Deposit or other assets measured at fair value as at December 31, 2021. Cash, accounts payable and accrued liabilities approximate their fair values as of December 31, 2022 and December 31, 2021, due to their short-term nature. Pension plan assets fair value is determined based on Level 2 inputs.

Investments

Investments	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The fair value and amortized cost of investments in short-term marketable debt securities by major security type as of December 31, 2022 are as follows: Amortized cost Gross unrealized gains Gross unrealized losses Fair value Eurocommercial Papers $ 42,265,129 $ 287,479 $ — $ 42,552,608 Certificates of Deposit 9,834,625 103,274 — 9,937,899 Total $ 52,099,754 $ 390,753 $ — $ 52,490,507 Of which classified within cash and cash equivalents 19,775,171 106,228 — 19,881,399 Of which classified within short-term marketable debt securities 32,324,583 284,525 — 32,609,108 The following table presents the changes in fair values of the Company’s short-term marketable debt securities, classified as Level 2 financial assets (in thousands): Beginning balance, January 1, 2022 $ — Other comprehensive income before reclassifications 706,586 Amounts reclassified from accumulated other comprehensive income (315,833) Ending balance, December 31, 2022 $ 390,753 As of December 31, 2022, the Company’s marketable debt securities are all due within one year.

Prepaid Expenses

Prepaid Expenses	12 Months Ended
	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses	Prepaid Expenses December 31, 2022 December 31, 2021 Non-clinical research and clinical development services $ 2,443,863 $ 547,586 Insurances 1,416,597 23,141 Other consulting and advisory services 105,651 31,930 Other prepayments 213,357 846,439 Total $ 4,179,468 $ 1,449,096 Prepaid expenses as of December 31, 2022 primarily relate to services expected to be received within the next 12 months.

Trade and Other Payables

Trade and Other Payables	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Trade and Other Payables	Trade and Other Payables December 31, 2022 December 31, 2021 Supply and manufacturing fees payable $ 65,979 $ 183,298 Other consulting and advisory services 51,658 71,938 Legal and intellectual property (“IP”) advisory fees payable 40,532 1,233,070 Research and development services 31,687 50,088 Other payables 65,116 30,896 Total $ 254,972 $ 1,569,290 December 31, 2022 December 31, 2021 Research and development services and license fees $ 5,803,432 $ 2,055,687 Bonuses and related employees compensation expenses 1,109,734 1,419,137 Consultant and other fees 218,021 49,211 Tax liabilities 109,826 63,922 Legal fees 15,832 930,354 Total $ 7,256,845 $ 4,518,311 Research and development expenses for the year ended December 31, 2022, primarily relate to the accrual of milestone payments in connection with Phase 2 clinical trials in the amount of $4.7 million.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Trade and Other Payables December 31, 2022 December 31, 2021 Supply and manufacturing fees payable $ 65,979 $ 183,298 Other consulting and advisory services 51,658 71,938 Legal and intellectual property (“IP”) advisory fees payable 40,532 1,233,070 Research and development services 31,687 50,088 Other payables 65,116 30,896 Total $ 254,972 $ 1,569,290 December 31, 2022 December 31, 2021 Research and development services and license fees $ 5,803,432 $ 2,055,687 Bonuses and related employees compensation expenses 1,109,734 1,419,137 Consultant and other fees 218,021 49,211 Tax liabilities 109,826 63,922 Legal fees 15,832 930,354 Total $ 7,256,845 $ 4,518,311 Research and development expenses for the year ended December 31, 2022, primarily relate to the accrual of milestone payments in connection with Phase 2 clinical trials in the amount of $4.7 million.

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	Leases In August 2021, the Company entered into an open-ended office lease agreement to lease approximately 2,300 square feet of space on the last two floors of the building located at Dorfstrasse 29, 6300, Zug Switzerland (the “ Office Lease ”) which was effective November 1, 2021. The management estimated the effective duration of the lease at inception and determined a period of 3 years, with expected expiration in November 2024. Payments under the Company’s lease agreement are fixed. The annual discount rate applied is 0.8%. The future minimum annual lease payments under these operating leases as of December 31, 2022 are as follows: Year ending December 31, Amount 2023 $ 155,300 2024 129,417 2025 — 2026 — 2027 — Thereafter — Total lease payments 284,717 Less imputed interest (2,137) Total lease liability 282,580 Less current portion of lease liability (153,629) Long-term portion operating lease liability $ 128,951 The current portion of the Company’s operating lease liability of $0.2 million as of December 31, 2022 is included in short-term portion of operating lease liabilities on the consolidated balance sheet. The Company recorded lease expense related to its operating lease right-of-use asset of $155,552 and $25,860 for the period ended December 31, 2022 and December 31, 2021, respectively. As a result of adopting ASC 842 in 2022, the Company recorded lease right-of-use, (ROU) asset and lease liabilities of $435,005 as of January 1, 2022.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Employee benefit plans	Employee Benefit Plans The Company operates a defined benefit pension plan in Switzerland (“ the Plan ”) and a defined contribution pension plan in the United Kingdom, in accordance with local regulations and practices. As of December 31, 2022 the Plan covers the Company’s employees in Switzerland with benefits in the event of death, disability, retirement, or termination of employment. A summary of the changes in projected benefit obligations (“ PBO ”) and plan assets is presented below: December 31, 2022 December 31, 2021 Beginning PBO $ 1,322,874 $ — Service cost 451,075 143,467 Interest cost 5,056 — Contributions by plan participants 138,243 64,954 Actuarial (gain) / losses (374,317) 174,012 Transfers (in) / out (204,695) 931,257 Foreign currency exchange rates changes (16,267) 9,184 Ending PBO $ 1,321,969 $ 1,322,874 December 31, 2022 December 31, 2021 Beginning fair value of plan assets $ 1,083,014 $ — Actual return on plan assets 15,522 5,835 Return on plan assets above expected return (115,877) — Contributions by the employer 138,243 73,448 Contributions by plan participants 138,243 64,954 Transfers (in) / out (204,695) 931,257 Foreign currency exchange rates changes (14,687) 7,520 Ending fair value of plan assets $ 1,039,763 $ 1,083,014 Amounts recorded on the consolidated balance sheet: December 31, 2022 December 31, 2021 Fair value of plan assets $ 1,039,763 $ 1,083,014 Present value of projected benefit obligation (1,321,969) (1,322,874) Funded status $ (282,206) $ (239,860) Amounts recorded in accumulated other comprehensive (income) / loss: December 31, 2022 December 31, 2021 Actuarial (gain) / loss - beginning of period $ 168,177 $ — Actuarial (gain) / loss of current year / period (268,076) 168,177 Amortization (1,817) — Total $ (101,716) $ 168,177 The assumptions used to calculate the ASC 715 liabilities are summarized in the table below: December 31, 2022 December 31, 2021 Discount rate 2.20 % p.a. 0.40 % p.a. Expected return on plan assets 3.80 % p.a. 1.50 % p.a. Inflation 1.80 % p.a. 1.10 % p.a. Long-term expected rate of salary increase 2.30 % p.a. 1.60 % p.a. Service cost of $451,075 was recognized in the net periodic benefit cost for the year ended December 31, 2022. The allocation of plan assets is presented below: December 31, 2022 December 31, 2021 Equities 34.11 % 35.13 % Bonds 28.89 % 30.89 % Mortgages 3.86 % 3.83 % Liquidity 2.41 % 2.90 % Real estate 27.17 % 24.37 % Alternative investments 3.40 % 2.88 % Infrastructure 0.16 % — % The fair value of plan assets is determined based on Level 2 inputs. As all members of the Plan are active, no future expected benefit payments are currently in payment and foreseen to occur within the next ten years.

Shareholders_ Equity (Deficit)

Shareholders’ Equity (Deficit)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Shareholders’ Equity (Deficit)	Shareholders’ Equity (Deficit) As a result of the Business Combination, the Company has retroactively restated the share numbers prior to April 5, 2022 to give effect to the Exchange Ratio. Series A Preferred Shares (1) Common Shares (1) Common Shares Held In Treasury (2) Class A Ordinary Shares (3) Class C Ordinary Shares (3) Total Number of Shares Authorized Issued Authorized Issued Issued Authorized Issued Authorized Issued Authorized Issued and Outstanding Balance - January 1, 2022 22,880,908 22,880,908 13,119,092 12,161,331 (1,942,837) — — — — 36,000,000 33,099,402 Share-based payment under the equity incentive plan ESPP — — — — 1,177,354 — — — — 1,177,354 Issuance of Class A Ordinary Shares upon Business Combination — — — — — 500,000,000 18,424,355 100,000,000 — 600,000,000 18,424,355 Conversion of MoonLake AG shares into Class A Ordinary Shares and Class C Ordinary Shares following the Business Combination (22,880,908) (22,880,908) (13,119,092) (12,161,331) 765,483 — 18,501,284 — 15,775,472 (36,000,000) — Conversion of Class C Ordinary Shares into Class A Ordinary Shares — — — — — — 2,051,961 — (2,051,961) — — Balance - December 31, 2022 — — — — — 500,000,000 38,977,600 100,000,000 13,723,511 600,000,000 52,701,111 _________________ (1) Fully paid-in registered shares with a par value of CHF 0.10 (2) Registered shares with a par value of CHF 0.10 held in treasury (3) Fully paid-in registered shares with a par value of $0.0001 As of December 31, 2022, the Company had the following classes of shares: Class A Ordinary Shares On April 6, 2022, the Company's Class A Ordinary Shares began trading on Nasdaq under the symbol “ MLTX ”. As of December 31, 2022, there were 38,977,600 Class A Ordinary Shares issued or outstanding. The Company is authorized to issue up to 500,000,000 Class A Ordinary Shares, par value $0.0001 per share. Holders of Class A Ordinary Shares are entitled to one vote for each share. Class C Ordinary Shares On the Closing Date, the Company issued 15,775,472 Class C Ordinary Shares to the ML Parties (other than the BVF Shareholders) in an amount equivalent to the ML Parties' (other than the BVF Shareholders) 468,968 MoonLake AG Common Shares multiplied by the Exchange Ratio. As of December 31, 2022, there were 13,723,511 Class C Ordinary Shares issued and outstanding. The Company is authorized to issue up to 100,000,000 Class C Ordinary Shares, with a par value $0.0001 per share. Each Class C Ordinary Share entitles the holders thereof to one vote per share, but carries no economic rights. At the Closing, MoonLake, MoonLake AG and each ML Party entered into a Restated and Amended Shareholders' Agreement (the “ A&R Shareholders' Agreement ”). With the intent to approximate the rights, obligations and restrictions that an ML Party would enjoy if it were a holder of Class A Ordinary Shares, the A&R Shareholders’ Agreement (i) imposes certain transfer and other restrictions on the ML Parties, (ii) provides for the waiver of certain statutory rights and (iii) establishes certain mechanics whereby MoonLake and each of the ML

Net loss per share

Net loss per share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net loss per share	Net Loss per Share As a result of the Business Combination, the Company has retroactively restated the weighted average number of outstanding prior to April 5, 2022 to give effect to the Exchange Ratio. The following table sets forth the loss per share calculations for the year ended December 31, 2022 compared to the period ended December 31, 2021: For the Year Ended December 31, 2022 For the Period from March 10, 2021 to December 31, 2021 Numerator Net loss attributable to controlling interests shareholders $ (49,973,249) $ (53,643,615) Denominator Total weighted average number of outstanding shares 29,361,353 7,840,707 Net loss per share – basic and diluted $ (1.70) $ (6.84) The weighted average number of shares used to calculate the net loss per share – basic for the year ended December 31, 2022 excludes 13,723,511 Class C Ordinary Shares as they do not carry economic rights. In the event that ML Parties (other than the BVF Shareholders) elected to convert their 407,968 MoonLake AG Common Shares into 13,723,511 Class A Ordinary Shares, the weighted average number of shares outstanding would have been 40,547,405 for the year ended December 31, 2022, resulting in a net loss per share of $(1.59). Upon conversion, 13,723,511 Class C Ordinary Shares would be forfeited and there would no longer be any noncontrolling interests. Upon conversion, the Company's number of Class A Ordinary Shares outstanding would be 52,701,111 as of March 20, 2023, the date the consolidated financial statements were issued.

Share-based Compensation

Share-based Compensation	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Share-based Compensation	Share-based Compensation As of December 31, 2022 the Company had the following share-based compensation arrangements: a. Restricted Founder Shares (as defined below) – created in April 2021 by MoonLake AG; b. The Employee Share Participation Plan (“ ESPP ”) – created in July 2021 by MoonLake AG; c. The Employee Stock Option Plan (“ ESOP ”) – created in July 2021 by MoonLake AG; d. MoonLake Immunotherapeutics 2022 Equity Incentive Plan – created in April 2022 by MoonLake Immunotherapeutics. The purpose of the arrangements is to attract and retain the best available personnel and to provide participants with additional incentive to increase their efforts on behalf and in the best interest of the Company and its subsidiaries. As a result of the Business Combination, the Company has adjusted the share numbers related to the Restricted Founder Shares and Common Shares (under the ESPP and ESOP) prior to the Business Combination by the Exchange Ratio. The assumptions used in the valuation of the awards granted prior to Closing of the Business Combination have not been adjusted. The reference to “ Common Shares ” in this Note 14 refers to shares in MoonLake AG. MoonLake AG's compensation plans are settled with Common Shares, and with a number of Class C Ordinary Shares determined multiplying the Common Shares by the Exchange Ratio. The owners of Common Shares have the right to exchange their Common Shares for a number of Class A Ordinary Shares derived using the Exchange Ratio. In the event MoonLake AG shareholders elect to exchange their Common Shares, such MoonLake AG shareholder forfeits a number of Class C Ordinary Shares equal to the number of Class A Ordinary Shares issued (please see Note 12 — Shareholders’ Equity (Deficit) - Class C Ordinary Shares ). For the year ended December 31, 2022, the Company has recognized an increase in equity in the consolidated balance sheet, and share-based compensation expense in the consolidated statement of operations of $9.7 million. The share-based compensation expense was driven by the following share-based compensation plans and programs: Compensation Plan Year Ended December 31, 2022 For the Period from March 10, 2021 to December 31, 2021 MoonLake AG Restricted Founder Shares $ 4,840,608 $ 8,837,092 ESPP 3,910,076 148,835 ESOP 539,713 66,982 MoonLake Immunotherapeutics 2022 Equity Incentive Plan 364,381 — Total share-based compensation expense 1 $ 9,654,778 $ 9,052,909 Of which: included in R&D expense 954,379 72,183 Of which: included in G&A expense 8,700,399 8,980,726 _________________ (1) In order to acquire the in-licensing agreement, the Company transferred to Merck KGaA, Darmstadt, Germany on April 28, 2021: (i) a cash consideration of $25.0 million; and (ii) an equity consideration of 99,000 Common Shares (the equivalent of 3,330,231 Class C Ordinary Shares) for a total payment of $1. The fair value of the equity consideration of $4,851,000 was recorded as share-based portion for the in-licensing agreement for the IPR&D asset (“ In-licensing Agreement ”) and does not belong to any compensation plan. As of December 31, 2022, 22,756 treasury shares (the equivalent of 765,482 Class C Ordinary Shares) and 14,596 Common Shares (the equivalent of 490,990 Class C Ordinary Shares) issuable from the authorized conditional capital shares remain available for future grants under the ESPP and the ESOP by MoonLake AG. MoonLake AG - Restricted Founder Shares On April 28, 2021, the shareholders’ agreement between the co-founders, the Series A investors and MoonLake AG imposed a reverse vesting condition on 90% of the total 110,000 Common Shares (the equivalent of 3,700,257 Class C Ordinary Shares) held by each of the three co-founders. Therefore, 99,000 Common Shares (the equivalent of 3,330,231 Class C Ordinary Shares) held by each of the co-founders were subject to these restrictions and considered unvested (the “ Restricted Founder Shares ”). The Restricted Founder Shares vest on the 28th of each month at a rate of 4.166% over a period of two years until April 28, 2023. If, before the end of the vesting period, the contractual relationship of the relevant co-founders is terminated, MoonLake AG in first priority, or any third party designated by it, and the other shareholders in second priority pro rata to their shareholdings, shall have an option to purchase all or a pro rata portion of the leaver shares that are unvested on the day the termination becomes effective at nominal value of CHF 0.10 (equivalent of $0.0001) per share. The assumptions used in the valuation of the Restricted Founder Shares awarded are summarized below: Grant date 4/28/2021 Estimated fair value per share of Restricted Founder Shares on the grant date ($) (1) 49 Estimated fair value of Restricted Founder Shares on the resignation date of one of the co-founders of MoonLake AG ($) (2) 336.39 Purchase price (CHF) 0.10 _________________ (1) MoonLake AG estimated the fair value of the Restricted Founder Shares with reference to the market-based transaction with the other Series A Preferred Shares Investors (refer to Note 9 of the audited consolidated financial statements for the period ended December 31, 2021). (2) MoonLake AG estimated the fair value of the Restricted Founder Shares at co-founder’s resignation date by dividing the Company Enterprise Value ($360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196). Grants awarded Restricted Founder Shares Program Awards outstanding at March 10, 2021 (Inception) — Awards granted for the period from March 10, 2021 to December 31, 2021 9,990,694 Repurchase of Common Shares following the resignation of a co-founder (1,942,837) Awards vested for the period from March 10, 2021 to December 31, 2021 (3,607,548) Awards outstanding at January 1, 2022 4,440,309 Awards vested for the year ended December 31, 2022 (3,330,231) Awards outstanding at December 31, 2022 1,110,078 As of December 31, 2022, MoonLake AG had $1.6 million of total unrecognized compensation expense related to the Restricted Founder Shares that will be recognized by April 28, 2023 with a monthly compensation expense of $403,361. Employee Share Participation Plan (ESPP) 2021-2025 - MoonLake AG The ESPP grants will vest 25% on each anniversary of the grant date. In the event of a termination of contractual relationship between the Company and the entitled employee, the awards can be deemed forfeited by MoonLake AG if certain conditions are met. Awards feature an accelerated vesting condition linked to a “Change of Control”, defined as any transfer of shares that results in the proposed acquirer holding more than 50% of the then issued share capital of MoonLake AG or the Company, as the case may be, where the grants will be deemed fully vested on the earlier of (i) 12 months (or such shorter period determined by the board of directors) after the occurrence of a “change of control” or (ii) the date after the occurrence of the change of control on which a termination notice is served to the participant by MoonLake AG (other than a bad leaver termination, described below) or by the participant for good cause (as defined under Swiss law or any other applicable foreign law). For awards made after September 30, 2021, the Closing of the Business Combination between MoonLake AG and Helix does not qualify as a Change of Control. The assumptions used in the valuation of the grants awarded under the ESPP for the period from March 10, 2021 to December 31, 2021, and for the year ended December 31, 2022 are summarized below: Assumptions for the awards issued for the period from March 10, 2021 to December 31, 2021 Grant date 7/27/2021 & 9/9/2021 Estimated fair value per share of Common Shares on the grant date ($) (1) 49 Purchase price (CHF) 0.10 _________________ (1) The Company estimated the fair value of the Common Shares with reference to the market-based transaction with the other Series A Preferred Shares Investors (refer Note 9 of the financial statements for the Period from March 10, 2021 to December 31, 2021) Grant date 10/25/21 Estimated fair value per share of Common Shares on the grant date ($) (2) 336.39 Purchase price (CHF) 0.10 _________________ (2) The Company estimated the fair value of the Common Shares by dividing the Company Enterprise Value (USD 360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196). Assumptions for the awards issued during the year ended December 31, 2022 Grant date 01/18/2022 Estimated fair value per share of Common Shares on the grant date ($) (1) 336.39 Purchase price (CHF) 0.10 _________________ (1) MoonLake AG estimated the fair value of the Common Shares by dividing the Company Enterprise Value ($360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196). Grants awarded Program ESPP Awards outstanding at March 10, 2021 (Inception) — Awards granted for the period from March 10, 2021 to December 31, 2021 1,060,561 Awards outstanding at January 1, 2022 1,060,561 Awards granted for the three months ended March 31, 2022 1,177,354 Awards outstanding at March 31, 2022 2,237,915 Awards granted for the three months ended June 30, 2022 — Awards granted for the year ended December 31, 2022 1,177,354 Awards outstanding at December 31, 2022 2,237,915 Awards vested at December 31, 2022 307,794 As of December 31, 2022, MoonLake AG had $9.5 million of total unrecognized compensation expense related to the ESPP that will be recognized over the weighted average period of 1.77 years. Employee Stock Option Plan (ESOP) 2021-2025 - MoonLake AG The ESOP grants will vest 25% on each anniversary of the grant date. In the event of a termination of contractual relationship between the Company and the entitled employee, options can be deemed forfeited by MoonLake AG if certain conditions are met. Awards feature an accelerated vesting condition linked to a “Change of Control”, defined as any transfer of shares that results in the proposed acquirer holding more than 50% of the then issued share capital of MoonLake AG or the Company, as the case may be, where the grants will be deemed fully vested on the earlier of (i) 12 months (or such shorter period determined by the board of directors) after the occurrence of a “change of control” or (ii) the date after the occurrence of the change of control on which a termination notice is served to the participant by MoonLake AG (other than a bad leaver termination, described below) or by the participant for good cause (as defined under Swiss law or any other applicable foreign law). For awards made after September 30, 2021, the Closing of the Business Combination between MoonLake AG and Helix does not qualify as a Change of Control. Assumptions for the awards issued for the period from March 10, 2021 to December 31, 2021 Grant date 9/9/2021 Estimated fair value of the option on the grant date using Black-Scholes model (USD) (1) 32.93 Exercise price (CHF) 43.80 Expected term of the award on the grant date (years) (2) 6 Expected volatility of the share price (3) 75 % Risk-free interest rate (4) 1 % Expected dividend rate — Grant date 10/25/2021 Estimated fair value of the option on the grant date using Black-Scholes model (USD) (5) 336.30 Exercise price (CHF) 0.10 Expected term of the award on the grant date (years) (2) 6 Expected volatility of the share price (3) 75 % Risk-free interest rate (4) 1 % Expected dividend rate — _________________ (1) The Company assumed a fair value per Common Share of USD 49 when estimating the fair value of the option. The fair value per Common Share was determined with reference to the market-based transaction with the other Series A Preferred Shares Investors (refer Note 9 of the financial statements for the Period from March 30, 2021 to December 31, 2021). (2) The expected term represents the period that share-based awards are expected to be outstanding. (3) The expected volatility was derived from the historical stock volatilities of comparable peer public companies within the Company’s industry. (4) The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the measurement date with maturities approximately equal to the expected term. (5) The Company estimated the fair value of the Common Shares by dividing the Company Enterprise Value (USD 360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196) Weighted average assumptions for the awards issued during the year ended December 31, 2022 Grant dates 5/1/2022, 6/22/2022 Estimated fair value of the option on the grant date using Black-Scholes model ($) (1) 172.57 Exercise price (CHF) 27.25 Expected term of the award on the grant date (years) (2) 6 Expected volatility of the share price (3) 0.75 Risk-free interest rate (4) 3 % Expected dividend rate 0 _________________ (1) MoonLake AG estimated the fair value of the Common Shares multiplying the MoonLake Immunotherapeutics closing date trading share price on the grant date by the Exchange Ratio. (2) The expected term represents the period that share-based awards are expected to be outstanding. (3) The expected volatility was derived from the historical stock volatilities of comparable peer public companies within the Company’s industry. (4) The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the measurement date with maturities approximately equal to the expected term. Grants awarded Program ESOP Awards outstanding at March 10, 2021 (Inception) — Awards granted for the period from March 10, 2021 to December 31, 2021 224,033 Awards outstanding at January 1, 2022 224,033 Awards granted for the year ended December 31, 2022 242,736 Awards outstanding at December 31, 2022 466,769 Awards exercisable at December 31, 2022 55,941 As of December 31, 2022, MoonLake AG had $1.8 million of total unrecognized compensation expense related to the ESOP that will be recognized over the weighted average period of 2.64 years. MoonLake Immunotherapeutics 2022 Equity Incentive Plan On April 5, 2022 (the “ Effective Date ”) the Company created the “MoonLake Immunotherapeutics 2022 Equity Incentive Plan” (the “ Equity Incentive Plan ”) to promote and closely align the interests of employees, officers, non-employee directors and other service providers of MoonLake Immunotherapeutics and its shareholders by providing share-based compensation and other performance-based compensation. The Equity Incentive Plan provides for the grant of options, stock appreciation rights, restricted stock units, restricted stock and other share-based awards and for incentive bonuses, which may be paid in cash, Common Shares or a combination thereof, as determined by the compensation committee of the board of directors or such other committee as designated by the board of directors to administer the Equity Incentive Plan. The Equity Incentive Plan shall remain available for the grant of awards until the 10th anniversary of the Effective Date. On April 6, 2022, the Company granted 180,000 options under the Equity Incentive Plan, each option representing the right to acquire one Class A Ordinary Share, par value $0.0001 per share, of MoonLake. The options will vest one-third on each April 6, 2023, April 6, 2024 and April 6, 2025. During the year ended December 31, 2022, no other grants were awarded under the Equity Incentive Plan. Grant date 4/6/2022 Estimated fair value of the option on the grant date using Black-Scholes model ($) 8.25 Exercise price ($) 12.25 Expected term of the award on the grant date (years) 6 Expected volatility of the share price 75 % Risk-free interest rate 3 % Expected dividend rate - Grants awarded MoonLake Immunotherapeutics 2022 Equity Incentive Plan Program Awards outstanding at January 1, 2022 — Awards granted for the year ended December 31, 2022 180,000 Awards outstanding at December 31, 2022 180,000 Awards exercisable at December 31, 2022 —

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income taxes	Income Taxes The Company's effective tax rate (“ ETR ”) was 0.1% and 0.1% for the year ended December 31, 2022, and for the period ended December 31, 2021, respectively. The Company is not aware of any items that would cause the quarterly or period-to-date ETR to be significantly different from the Company's annual ETR. The difference between the income tax provision that would be derived by applying the statutory rate to the Company's loss before income taxes and the income tax provision recorded was primarily attributable to the change in the valuation allowance. The Company continues to incur losses for the Cayman Island and Swiss entity and its ability to utilize the deferred tax asset related to the tax losses is not considered more likely than not. The Company is subject to taxation in the Canton of Zug, Switzerland. For the years ended December 31, 2022 and 2021, the Company did not incur any significant income tax expense or benefit as the Company incurred tax losses and provided a full valuation allowance. The components of income or loss before income tax were as follows: Year Ended December 31, 2022 For the period from March 10, 2021 (Inception) to December 31, 2021 Switzerland $ (62,115,251) $ (53,663,726) Foreign (2,354,434) 24,866 Total $ (64,469,685) $ (53,638,860) The provision for income taxes differs from the amount computed by applying the statutory income tax rate to loss before income taxes as follows: Year Ended December 31, 2022 For the period from March 10, 2021 (Inception) to December 31, 2021 Statutory income tax rate 11.9 % 11.9 % Change in prior year estimates 0.1 % — % Change in valuation allowance (10.0) % (10.9) % Non-deductible expense (1.4) % (1.0) % Other (0.5) % 0.1 % Effective income tax rate 0.1 % 0.1 % Significant components of the Company’s deferred tax assets were: December 31, 2022 December 31, 2021 Intangible assets $ 4,492,435 $ 2,963,340 Defined benefit plan 33,451 8,497 Net operating loss carry forward 7,210,383 2,873,281 Total deferred tax assets (gross) 11,736,269 5,845,118 Valuation allowance (11,736,269) (5,845,118) Total deferred tax asset (net) $ — $ — As of December 31, 2022, the Company’s net deferred tax assets before valuation allowance were USD 11.7 million. In assessing the realizability of its deferred tax assets, the Company considers whether it is more likely than not that some portion or all of its deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. Based on the weight of all evidence, the Company has determined that it is not more likely than not that the net deferred tax assets will be realized. A valuation allowance of USD 11.7 million has been recorded against the deferred tax assets. As of December 31, 2022, MoonLake AG had net operating losses of approximately USD 60.8 million of which USD 14.9 million will expire in 2028 and USD 45.9 million will expire in 2029. The Company’s net operating losses will not be subject to any limitation due to the change in the ownership according to Swiss Income Tax Law. The Company has no unrecognized tax benefits and does not expect that uncertain tax benefits will change significantly in the next twelve months.

Commitment and Contingencies

Commitment and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingencies	Commitments and Contingencies Commitments The Company has entered into agreements as of December 31, 2022 primarily in regards to advancement of clinical and non-clinical research program expenses, production of drug substance and technology transfer of the drug product process for SLK. As of December 31, 2022, the total committed amount under these agreements not yet recognized amounted to $31.9 million. On April 2021, MoonLake AG acquired the SLK program from MHKDG, a related party to the Company, which includes contractual milestone payments related to the achievement of pre-specified research, development, regulatory and commercialization events and indemnification provisions, which are common in such agreements. Pursuant to the agreements, the Company is obligated to make research and development and regulatory milestone payments upon the occurrence of certain events and royalty payments based on net sales. Subject to the terms of the license, additional milestone payments of up to €299.6 million ($319.5 million using a December 31, 2022 exchange rate) are potentially payable upon satisfying specific milestones related to regulatory filing acceptance, first commercial sales, and aggregate annual net sales. The milestone payments are payable in cash. Milestone payments due prior to obtaining regulatory approval will be recorded as research and development expense upon determination that a milestone payment is probable to occur. Milestone payments due after obtaining regulatory approval will be capitalized when and if incurred. The Company will use commercially reasonable efforts to cause the milestones to occur. However, if the Company reasonably determines that a technical failure or commercial failure has occurred with respect to all or a part of the SLK Program, the Company, at its sole discretion, can terminate all or part of the SLK Program. In addition, the In-licensing Agreement requires the Company to pay royalties within the range of low to mid-teen percent of net sales. Royalties will be recognized in the consolidated statement of operations when net sales are recognized.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Loan Agreements with BVF Shareholders On October 15, 2021, MoonLake AG entered into a loan agreement with the BVF Shareholders, pursuant to which Biotechnology Value Fund, L.P., Biotechnology Value Fund II, L.P., and Biotechnology Value Trading Fund OS, L.P. loaned USD 8,139,000, USD 5,946,000, and USD 915,000, respectively (USD 15,000,000 in aggregate), for the financing of general corporate purposes of MoonLake AG, including product and technology development, operations, sales and marketing, management expenses, and salaries. The loans was interest-free and had to be repaid by MoonLake AG prior to the earlier of (i) as soon as practicable after the closing date of the Business Combination, but no later than two (2) business days, and (ii) June 30, 2022 (the “ Maturity Date ”). The loan was interest-free and was repaid in full on April 11, 2022.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Partial Share Conversion On February 16, 2023, pursuant to the A&R Shareholders’ Agreement, a ML Party submitted an exchange notice to the Company, pursuant to which such ML Party effected the conversion of 5,250 MoonLake AG Common Shares and 176,603 Class C Ordinary Shares into 176,603 Class A Ordinary Shares using the Exchange Ratio. Please refer to Note 12 — Shareholders’ Equity (Deficit) — Class C Ordinary Shares for more information regarding the conversion mechanics.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of presentation	Basis of Presentation The accompanying consolidated financial statements include those of the Company and its subsidiaries, MoonLake AG and MoonLake Immunotherapeutics Ltd., after elimination of all intercompany accounts and transactions. The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“ GAAP ”). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ ASC ”) and Accounting Standards Updates (“ ASU ”) of the Financial Accounting Standards Board (“ FASB ”). Pursuant to ASC 805, for financial accounting and reporting purposes, MoonLake AG was deemed the accounting acquirer and Helix was treated as the accounting acquiree, and the Business Combination was accounted for as a reverse recapitalization. Accordingly, the Business Combination was treated as the equivalent of MoonLake AG issuing shares for the net assets of Helix, accompanied by a recapitalization. The net assets of Helix were stated at historical costs, with no goodwill or other intangible assets recorded, and are consolidated with MoonLake AG’s financial statements on the Closing Date. In accordance with the Business Combination Agreement, the ML Parties received 33.638698 Ordinary Shares in the Company for every MoonLake AG Common Share or Series A Preferred Share (the “ Exchange Ratio ”). The BVF Shareholders received 18,501,284 Class A Ordinary Shares whereas the rest of the ML Parties (excluding the BVF Shareholders) received 15,775,472 Class C Ordinary Shares which can be converted into Class A Ordinary Shares at the discretion of the shareholder (refer to Note 12 — Shareholders’ Equity (Deficit) for further details on the classes of ordinary shares). The number of shares, and the number of shares within the net income (loss) per share held by the ML Parties in MoonLake AG prior to the Business Combination have been adjusted by the Exchange Ratio to reflect the equivalent number of ordinary shares in the Company (identified as “ the equivalent of ” throughout these consolidated financial statements). Certain MoonLake AG shareholders (ML Parties other than the BVF Shareholders), did not exchange their shares in MoonLake AG for Class A Ordinary Shares in the Company and therefore continued to hold an economic interest in MoonLake AG and Class C Ordinary Shares in the Company. The Company recognized a noncontrolling interest equal to the ML Parties’ (other than the BVF Shareholders) proportionate interest in the net assets of MoonLake AG. All amounts are presented in U.S. Dollar (“ $ ”), unless otherwise indicated. The term “ Swiss franc ” and “ CHF ” refer to the legal currency of Switzerland, and “ € ” refers to Euros.
Use of estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires the Company to make judgments, estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of expenses. The significant judgments, estimates and assumptions relevant to the Company relate to: • determining whether the in-process research and development expenditure (“ IPR&D ”) has an alternative future use; • estimating the fair value of the portion of the aggregate purchase price relating to its own shares in connection with the acquisition of the in-license agreement; • determining assumptions used in determining the fair value of share-based compensation; • estimating the recoverability of the deferred tax asset; and • estimating the amount of accruals in connection with the completion of clinical trial milestones. The Company bases its judgments and estimates on various factors and information, which may include, but are not limited to, the Company’s forecasts and future plans, current economic conditions and observable market-based transactions of its own shares, the results of which form the basis for making judgments about the carrying value of assets and liabilities and recorded amounts of expenses that are not readily apparent from other sources. To the extent there are material differences between the Company’s estimates and the actual results, the Company’s future results of operation may be affected.
Cash and cash equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value. As of December 31, 2022, the Company considers $19.9 million of short-term marketable debt securities in the form of eurocommercial papers to be cash equivalents. As of December 31, 2021, the Company did not have any cash equivalents.
Marketable securities and short-term investments	Marketable securities and short-term investments The Company invests in short-term marketable securities in the form of debt securities. At the time of purchase, the Company assesses whether such debt security should be classified as held-to-maturity or available-for-sale debt securities. Debt securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. Held-to-maturity debt securities are carried at amortized cost, adjusted for accretion of discounts or amortization of premiums to maturity computed under the effective interest method. Such accretion or amortization is included in “Interest and dividend income” Marketable debt securities not classified as held-to-maturity are classified as available-for-sale and reported at fair value. Net unrealized gains and losses on available-for-sale debt securities are excluded from the determination of earnings and are instead recognized in the “Accumulated other comprehensive income (loss)” component of shareholder’ equity (deficit) until realized. Realized gains and losses on available-for-sale debt securities are computed based upon the historical cost of these securities, using the specific identification method. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the security. Dividend and interest income are recognized when earned. Realized gains and losses are included in earnings and the cost of securities sold is determined using the specific-identification method. Marketable debt securities are classified as either “Cash and cash equivalents” or “Short‑term marketable debt securities” according to their original maturity at the time of acquisition.
Concentration of credit risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist of cash accounts in a large financial institution which, at times, may exceed the CHF 100,000 deposit protection limit. The Company believes it is not exposed to significant credit risk due to the financial strength of the depository institutions in which the cash and cash equivalents are held. Further, the Company's investment strategy for cash (in excess of current business requirements) is set to invest in short-term securities. Management actively monitors
Fair value measurements	Fair Value Measurements The Company follows the guidance included in ASC 820, Fair Value Measurement. 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. There are three levels of inputs to fair value measurements: • Level 1, meaning the use of quoted prices for identical instruments in active markets; • Level 2, meaning the use of quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active or are directly or indirectly observable; and • Level 3, meaning the use of unobservable inputs. Observable market data is used when available.
Segment information	Segment Information The Company operates as a single operating segment. The Company’s chief operating decision maker, its Chief Executive Officer, manages the Company’s operations on a stand-alone basis for the purposes of allocating resources, and assessing financial performance.
Property and equipment	Property and Equipment Property and equipment, net is stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method based on the estimated useful lives of three
Research and development contract costs and accruals	Research and Development Contract Costs and Accruals Research and development expenses include employee payroll, consulting, contract research and contract manufacturing costs attributable to research and development activities and are expensed as incurred. Upfront payments and milestone payments made for the licensing of technology are expensed as research and development expenses in the period in which it is probable that a liability has been incurred. Advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed. The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.
Share-based transaction	Share-Based Transaction Goods or services received in a share-based payment transaction are measured using a fair value-based measure. Stock-Based Compensation The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to eligible employees, members of the board of directors and independent contractors that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgements about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s common stock on the date of the grant. For all stock options granted, the Company calculated the expected term as the period that share-based awards are expected to be outstanding. The estimate of expected volatility is based on comparative companies’ volatility within the Company's industry. The risk-free rate is based on the yield available on United States Treasury zero-coupon issues corresponding to the expected term of the award. The fair value of the common stock granted under the ESPP has historically been estimated by management with reference to the market-based transaction with the other Series A Preferred Shares Investors, as there was no public market for the common stock. Share-based payment arrangements are accounted for under the fair value method. Total compensation is measured at grant date, based on the fair value of the award at that date, and recorded in earnings over the period the employees are required to render service. The Company recognizes compensation cost only for those awards expected to meet the service conditions on a straight-line basis over the requisite service period of the award.
Foreign currency	Foreign Currency The functional currency of the Company and its subsidiaries is the U.S. dollar. Balances and transactions denominated in foreign currencies are converted as follows: monetary assets and liabilities are translated using exchange rates in effect at the balance sheet dates and non-monetary assets and liabilities are translated at historical exchange rates. Revenue and expenses are translated at the daily exchange rate on the respective accounting date. Gains or losses from foreign currency translation are included in the consolidated statement of operations. The Company recognized foreign currency transaction gain of $325,317 for the year ended December 31, 2022 (“the period ended December 31, 2022”) and a foreign currency transaction loss of $59,660 for the period ended December 31, 2021.
Income taxes	Income Taxes The Company accounts for income taxes by using the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. A valuation allowance is recorded to the extent it is more likely than not that all or a portion of the Company's deferred tax assets will not be realized. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date.
Net loss per Class A Ordinary Shares	Net Loss per Class A Ordinary Shares Basic net loss per Class A Ordinary Share is calculated using the two-class method under which earnings are allocated to both Class A Ordinary Shares and participating securities. Basic net loss per share is calculated by dividing the net loss attributable to Class A Ordinary Shares by the weighted-average number of Class A Ordinary Shares outstanding for the period. The diluted net loss per Class A Ordinary Share is computed by dividing the net loss using the weighted-average number of Class A Ordinary Shares and, if dilutive, potential Class A Ordinary Shares outstanding during the period.
Acquisitions	Acquisitions The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first assessing whether substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. The Company acquired the Sonelokimab program (the “ SLK Program ”) during the period ended December 31, 2021 and determined that substantially all of the fair value of the gross assets acquired related to IPR&D of SLK. Therefore, this transaction was accounted for as an asset acquisition. IPR&D represents incomplete technologies that the Company acquires, which at the time of acquisition, are still under development and have no alternative future use. The fair value of such technologies is expensed upon acquisition. A technology is considered to have an alternative future use if it is probable that the Company will use the asset in its current, incomplete state as it existed at the acquisition date, in another research and development project that has not yet commenced, and economic benefit is anticipated from that use. If a technology is determined to have an alternative future use, then the fair value of the program would be recorded as an asset on the balance sheet rather than expensed. Contingent consideration payments (for example milestone payments due upon the occurrence of a specific event) in asset acquisitions are recognized in the period in which it is probable that a liability has been incurred (unless the contingent consideration meets the definition of a derivative, in which case the amount becomes part of the cost in the asset acquired). Upon recognition of the contingent consideration payment, the amount is expensed if it relates to IPR&D or capitalized if it relates to a developed product which is generally considered to be when clinical trials have been completed and regulatory approval obtained. Future royalty payments due on net sales will be recognized in cost of goods sold when net sales are recognized.
Pension accounting	Pension Accounting The Company accounts for pension assets and liabilities in accordance with ASC 715, Compensation – Retirement Benefits, which requires the recognition of the funded status of pension plans in the Company’s consolidated balance sheet. The liability in respect to defined benefit pension plans is the projected benefit obligation calculated annually by independent actuaries using the projected unit credit method. The projected benefit obligation as of December 31, 2022 represents the actuarial present value of the estimated future payments required to settle the obligation that is attributable to employee services rendered before that date. Service costs for such pension plans, represented in the net periodic benefit cost, are included in the personnel expenses of the various functions where the employees are engaged. The other components of net benefit cost are included in the consolidated statement of operations separately from the service cost component, in “ other income (expenses), net
Recently adopted and issued accounting pronouncements not yet adopted	Recently Adopted Accounting Pronouncements Leases In February 2016, the FASB issued ASU No. 2016-02, Leases Topic 842 (“ ASU 2016-02 ”) . The guidance in ASU 2016-02 supersedes the lease recognition requirements in ASC 840, Leases. ASU 2016-02 requires an entity to recognize assets and liabilities arising from a lease for both financing and operating leases, along with additional qualitative and quantitative disclosures. ASU 2016-02 is effective for fiscal years beginning after December 15, 2021, and for interim periods within fiscal years beginning after December 15, 2022, with early adoption permitted. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842) : Targeted Improvements, which allows entities to elect a modified retrospective transition method where entities may continue to apply the existing lease guidance during the comparative periods and apply the new lease requirements through a cumulative effect adjustment in the period of adoptions rather than in the earliest period presented. The Company determines if an arrangement is or contains a lease at contract inception. For these arrangements, it is evaluated if the arrangement involves an identified asset that is physically distinct or whether the Company has the right to substantially all of the capacity of an identified asset that is not physically distinct. In arrangements that involve an identified asset, there is also judgment in evaluating if the Company has the right to direct the use of that asset. MoonLake does not have any finance leases. The Company only has one operating lease related to the office space located in Dorfstrasse 29, 6300, Zug, Switzerland. The operating lease is recognized over a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property. Right-of-Use (“ RoU ”) assets and lease liabilities are measured at the lease commencement date based on the present value of the remaining lease payments over the lease term, determined using the discount rate for the lease at the commencement date. Because the rate implicit in the leases is not readily determinable, the Company uses the incremental borrowing rate as the discount rate, which approximates the interest rate at which the Company could borrow on a collateralized basis with similar terms and payments and in similar economic environments. Leases with an initial term of 12 months or less and that do not have the option to purchase the underlying asset are not recorded on the balance sheet, with lease expense for these leases recognized on a straight-line basis over the lease term commencing on the date the Company has the right to use the leased property. Recently Issued Accounting Pronouncements not yet Adopted The Company is an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012 (“ JOBS Act ”). As such the Company is eligible for exemptions from various reporting requirements applicable to other public companies that are not emerging growth companies, including reduced reporting and extended transition periods to comply with new or revised accounting standards for public business entities. The Company has elected to avail itself of this exemption and, therefore, will not be subject to the timeline for adopting new or revised accounting standards for public business entities that are not emerging growth companies, and will follow the transition guidance applicable to private companies. Recently issued accounting pronouncements not yet adopted, that the Company plans to adopt, are not expected to have a material impact on the Company’s consolidated financial position, operating results, cash flows, or disclosures.

Business Combination Agreemen_2

Business Combination Agreement with Helix and Recapitalization (Tables)	12 Months Ended
	Dec. 31, 2022
Reverse Recapitalization [Abstract]
Summary of Net Proceeds and Ordinary Shares Issued	Summary of Net Proceeds The following table summarizes the elements of the net proceeds from the Business Combination: in thousands Investments held in Trust Account $ 115,051 Less cash to cover redemptions of the Class A Ordinary Shares issued by Helix prior to the Closing Date (80,842) Plus PIPE investment 116,000 Less Helix transaction expense (15,520) of which accrued expenses (5,798) of which deferred IPO underwriting fee (4,025) of which other transaction expenses (5,697) Available Closing Date Cash $ 134,689 Summary of Ordinary Shares Issued The following table summarizes the number of Ordinary Shares outstanding immediately following the consummation of the Business Combination: Helix Acquisition Corp. Ordinary Shares prior to the Business Combination 14,805,000 Of which Class A Ordinary Shares (Helix management - IPO private placement shares) 430,000 Of which Class A Ordinary Shares redeemable 11,500,000 Of which Class B Ordinary Shares (Helix management - sponsor promote) 2,875,000 Less redemptions of the Class A Ordinary Shares issued by Helix prior to the Closing Date (8,080,645) Plus issuance of Helix Class A Ordinary Shares to PIPE Investors 11,700,000 Plus issuance of Helix Class A Ordinary Shares to BVF Shareholders 18,501,284 Total MoonLake Class A Ordinary Shares Outstanding at Closing 36,925,639 Plus issuance of Helix Class C Ordinary Shares to ML Parties (other than the BVF Shareholders) 15,775,472 Total MoonLake Class A and Class C Ordinary Shares Outstanding at Closing 52,701,111

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of debt securities by level within the fair value hierarchy	The following table presents the Company’s short-term marketable debt securities by level within the fair value hierarchy: December 31, 2022 Level 1 Level 2 Level 3 Total Eurocommercial papers (1) $ — $ 42,552,608 $ — $ 42,552,608 Certificates of deposit — 9,937,899 — 9,937,899 Total $ — $ 52,490,507 $ — $ 52,490,507 _________________ (1) Eurocommercial papers in the amount of $19.9 million are classified as cash and cash equivalents.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Schedule of investments in short-term marketable debt securities	The fair value and amortized cost of investments in short-term marketable debt securities by major security type as of December 31, 2022 are as follows: Amortized cost Gross unrealized gains Gross unrealized losses Fair value Eurocommercial Papers $ 42,265,129 $ 287,479 $ — $ 42,552,608 Certificates of Deposit 9,834,625 103,274 — 9,937,899 Total $ 52,099,754 $ 390,753 $ — $ 52,490,507 Of which classified within cash and cash equivalents 19,775,171 106,228 — 19,881,399 Of which classified within short-term marketable debt securities 32,324,583 284,525 — 32,609,108
Schedule of fair value changes of marketable securities	The following table presents the changes in fair values of the Company’s short-term marketable debt securities, classified as Level 2 financial assets (in thousands): Beginning balance, January 1, 2022 $ — Other comprehensive income before reclassifications 706,586 Amounts reclassified from accumulated other comprehensive income (315,833) Ending balance, December 31, 2022 $ 390,753

Prepaid Expenses (Tables)

Prepaid Expenses (Tables)	12 Months Ended
	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid expenses	December 31, 2022 December 31, 2021 Non-clinical research and clinical development services $ 2,443,863 $ 547,586 Insurances 1,416,597 23,141 Other consulting and advisory services 105,651 31,930 Other prepayments 213,357 846,439 Total $ 4,179,468 $ 1,449,096

Trade and Other Payables (Table

Trade and Other Payables (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Trade and other payables, current	December 31, 2022 December 31, 2021 Supply and manufacturing fees payable $ 65,979 $ 183,298 Other consulting and advisory services 51,658 71,938 Legal and intellectual property (“IP”) advisory fees payable 40,532 1,233,070 Research and development services 31,687 50,088 Other payables 65,116 30,896 Total $ 254,972 $ 1,569,290

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Schedule of accrued expenses and other current liabilities	December 31, 2022 December 31, 2021 Research and development services and license fees $ 5,803,432 $ 2,055,687 Bonuses and related employees compensation expenses 1,109,734 1,419,137 Consultant and other fees 218,021 49,211 Tax liabilities 109,826 63,922 Legal fees 15,832 930,354 Total $ 7,256,845 $ 4,518,311

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Future minimum lease payments	The future minimum annual lease payments under these operating leases as of December 31, 2022 are as follows: Year ending December 31, Amount 2023 $ 155,300 2024 129,417 2025 — 2026 — 2027 — Thereafter — Total lease payments 284,717 Less imputed interest (2,137) Total lease liability 282,580 Less current portion of lease liability (153,629) Long-term portion operating lease liability $ 128,951

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets	A summary of the changes in projected benefit obligations (“ PBO ”) and plan assets is presented below: December 31, 2022 December 31, 2021 Beginning PBO $ 1,322,874 $ — Service cost 451,075 143,467 Interest cost 5,056 — Contributions by plan participants 138,243 64,954 Actuarial (gain) / losses (374,317) 174,012 Transfers (in) / out (204,695) 931,257 Foreign currency exchange rates changes (16,267) 9,184 Ending PBO $ 1,321,969 $ 1,322,874 December 31, 2022 December 31, 2021 Beginning fair value of plan assets $ 1,083,014 $ — Actual return on plan assets 15,522 5,835 Return on plan assets above expected return (115,877) — Contributions by the employer 138,243 73,448 Contributions by plan participants 138,243 64,954 Transfers (in) / out (204,695) 931,257 Foreign currency exchange rates changes (14,687) 7,520 Ending fair value of plan assets $ 1,039,763 $ 1,083,014
Schedule of Defined Benefit Plans Disclosures	Amounts recorded on the consolidated balance sheet: December 31, 2022 December 31, 2021 Fair value of plan assets $ 1,039,763 $ 1,083,014 Present value of projected benefit obligation (1,321,969) (1,322,874) Funded status $ (282,206) $ (239,860)
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)	Amounts recorded in accumulated other comprehensive (income) / loss: December 31, 2022 December 31, 2021 Actuarial (gain) / loss - beginning of period $ 168,177 $ — Actuarial (gain) / loss of current year / period (268,076) 168,177 Amortization (1,817) — Total $ (101,716) $ 168,177
Defined Benefit Plan, Assumptions	The assumptions used to calculate the ASC 715 liabilities are summarized in the table below: December 31, 2022 December 31, 2021 Discount rate 2.20 % p.a. 0.40 % p.a. Expected return on plan assets 3.80 % p.a. 1.50 % p.a. Inflation 1.80 % p.a. 1.10 % p.a. Long-term expected rate of salary increase 2.30 % p.a. 1.60 % p.a.
Defined Benefit Plan, Plan Assets, Allocation	The allocation of plan assets is presented below: December 31, 2022 December 31, 2021 Equities 34.11 % 35.13 % Bonds 28.89 % 30.89 % Mortgages 3.86 % 3.83 % Liquidity 2.41 % 2.90 % Real estate 27.17 % 24.37 % Alternative investments 3.40 % 2.88 % Infrastructure 0.16 % — %

Shareholders_ Equity (Deficit)

Shareholders’ Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Schedule of Stock Authorized and Issued	As a result of the Business Combination, the Company has retroactively restated the share numbers prior to April 5, 2022 to give effect to the Exchange Ratio. Series A Preferred Shares (1) Common Shares (1) Common Shares Held In Treasury (2) Class A Ordinary Shares (3) Class C Ordinary Shares (3) Total Number of Shares Authorized Issued Authorized Issued Issued Authorized Issued Authorized Issued Authorized Issued and Outstanding Balance - January 1, 2022 22,880,908 22,880,908 13,119,092 12,161,331 (1,942,837) — — — — 36,000,000 33,099,402 Share-based payment under the equity incentive plan ESPP — — — — 1,177,354 — — — — 1,177,354 Issuance of Class A Ordinary Shares upon Business Combination — — — — — 500,000,000 18,424,355 100,000,000 — 600,000,000 18,424,355 Conversion of MoonLake AG shares into Class A Ordinary Shares and Class C Ordinary Shares following the Business Combination (22,880,908) (22,880,908) (13,119,092) (12,161,331) 765,483 — 18,501,284 — 15,775,472 (36,000,000) — Conversion of Class C Ordinary Shares into Class A Ordinary Shares — — — — — — 2,051,961 — (2,051,961) — — Balance - December 31, 2022 — — — — — 500,000,000 38,977,600 100,000,000 13,723,511 600,000,000 52,701,111 _________________ (1) Fully paid-in registered shares with a par value of CHF 0.10 (2) Registered shares with a par value of CHF 0.10 held in treasury

Net loss per share (Tables)

Net loss per share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of earnings per share, basic and diluted	The following table sets forth the loss per share calculations for the year ended December 31, 2022 compared to the period ended December 31, 2021: For the Year Ended December 31, 2022 For the Period from March 10, 2021 to December 31, 2021 Numerator Net loss attributable to controlling interests shareholders $ (49,973,249) $ (53,643,615) Denominator Total weighted average number of outstanding shares 29,361,353 7,840,707 Net loss per share – basic and diluted $ (1.70) $ (6.84)

Share-based Compensation (Table

Share-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount	The share-based compensation expense was driven by the following share-based compensation plans and programs: Compensation Plan Year Ended December 31, 2022 For the Period from March 10, 2021 to December 31, 2021 MoonLake AG Restricted Founder Shares $ 4,840,608 $ 8,837,092 ESPP 3,910,076 148,835 ESOP 539,713 66,982 MoonLake Immunotherapeutics 2022 Equity Incentive Plan 364,381 — Total share-based compensation expense 1 $ 9,654,778 $ 9,052,909 Of which: included in R&D expense 954,379 72,183 Of which: included in G&A expense 8,700,399 8,980,726 _________________ (1) In order to acquire the in-licensing agreement, the Company transferred to Merck KGaA, Darmstadt, Germany on April 28, 2021: (i) a cash consideration of $25.0 million; and (ii) an equity consideration of 99,000 Common Shares (the equivalent of 3,330,231 Class C Ordinary Shares) for a total payment of $1. The fair value of the equity consideration of $4,851,000 was recorded as share-based portion for the in-licensing agreement for the IPR&D asset (“ In-licensing Agreement ”) and does not belong to any compensation plan.
Schedule of Share-Based Payment Award, Non-Option Equity Instruments, Valuation Assumptions	The assumptions used in the valuation of the Restricted Founder Shares awarded are summarized below: Grant date 4/28/2021 Estimated fair value per share of Restricted Founder Shares on the grant date ($) (1) 49 Estimated fair value of Restricted Founder Shares on the resignation date of one of the co-founders of MoonLake AG ($) (2) 336.39 Purchase price (CHF) 0.10 _________________ (1) MoonLake AG estimated the fair value of the Restricted Founder Shares with reference to the market-based transaction with the other Series A Preferred Shares Investors (refer to Note 9 of the audited consolidated financial statements for the period ended December 31, 2021). (2) MoonLake AG estimated the fair value of the Restricted Founder Shares at co-founder’s resignation date by dividing the Company Enterprise Value ($360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196).
Nonvested Restricted Stock Shares Activity	Grants awarded Restricted Founder Shares Program Awards outstanding at March 10, 2021 (Inception) — Awards granted for the period from March 10, 2021 to December 31, 2021 9,990,694 Repurchase of Common Shares following the resignation of a co-founder (1,942,837) Awards vested for the period from March 10, 2021 to December 31, 2021 (3,607,548) Awards outstanding at January 1, 2022 4,440,309 Awards vested for the year ended December 31, 2022 (3,330,231) Awards outstanding at December 31, 2022 1,110,078
Schedule of Nonvested Share Activity	The assumptions used in the valuation of the grants awarded under the ESPP for the period from March 10, 2021 to December 31, 2021, and for the year ended December 31, 2022 are summarized below: Assumptions for the awards issued for the period from March 10, 2021 to December 31, 2021 Grant date 7/27/2021 & 9/9/2021 Estimated fair value per share of Common Shares on the grant date ($) (1) 49 Purchase price (CHF) 0.10 _________________ (1) The Company estimated the fair value of the Common Shares with reference to the market-based transaction with the other Series A Preferred Shares Investors (refer Note 9 of the financial statements for the Period from March 10, 2021 to December 31, 2021) Grant date 10/25/21 Estimated fair value per share of Common Shares on the grant date ($) (2) 336.39 Purchase price (CHF) 0.10 _________________ (2) The Company estimated the fair value of the Common Shares by dividing the Company Enterprise Value (USD 360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196). Assumptions for the awards issued during the year ended December 31, 2022 Grant date 01/18/2022 Estimated fair value per share of Common Shares on the grant date ($) (1) 336.39 Purchase price (CHF) 0.10 _________________ (1) MoonLake AG estimated the fair value of the Common Shares by dividing the Company Enterprise Value ($360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196). Grants awarded Program ESPP Awards outstanding at March 10, 2021 (Inception) — Awards granted for the period from March 10, 2021 to December 31, 2021 1,060,561 Awards outstanding at January 1, 2022 1,060,561 Awards granted for the three months ended March 31, 2022 1,177,354 Awards outstanding at March 31, 2022 2,237,915 Awards granted for the three months ended June 30, 2022 — Awards granted for the year ended December 31, 2022 1,177,354 Awards outstanding at December 31, 2022 2,237,915 Awards vested at December 31, 2022 307,794
Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions	The assumptions used in the valuation of the grants awarded under the ESPP for the period from March 10, 2021 to December 31, 2021, and for the year ended December 31, 2022 are summarized below: Assumptions for the awards issued for the period from March 10, 2021 to December 31, 2021 Grant date 7/27/2021 & 9/9/2021 Estimated fair value per share of Common Shares on the grant date ($) (1) 49 Purchase price (CHF) 0.10 _________________ (1) The Company estimated the fair value of the Common Shares with reference to the market-based transaction with the other Series A Preferred Shares Investors (refer Note 9 of the financial statements for the Period from March 10, 2021 to December 31, 2021) Grant date 10/25/21 Estimated fair value per share of Common Shares on the grant date ($) (2) 336.39 Purchase price (CHF) 0.10 _________________ (2) The Company estimated the fair value of the Common Shares by dividing the Company Enterprise Value (USD 360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196). Assumptions for the awards issued during the year ended December 31, 2022 Grant date 01/18/2022 Estimated fair value per share of Common Shares on the grant date ($) (1) 336.39 Purchase price (CHF) 0.10 _________________ (1) MoonLake AG estimated the fair value of the Common Shares by dividing the Company Enterprise Value ($360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196). Grants awarded Program ESPP Awards outstanding at March 10, 2021 (Inception) — Awards granted for the period from March 10, 2021 to December 31, 2021 1,060,561 Awards outstanding at January 1, 2022 1,060,561 Awards granted for the three months ended March 31, 2022 1,177,354 Awards outstanding at March 31, 2022 2,237,915 Awards granted for the three months ended June 30, 2022 — Awards granted for the year ended December 31, 2022 1,177,354 Awards outstanding at December 31, 2022 2,237,915 Awards vested at December 31, 2022 307,794
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions	Assumptions for the awards issued for the period from March 10, 2021 to December 31, 2021 Grant date 9/9/2021 Estimated fair value of the option on the grant date using Black-Scholes model (USD) (1) 32.93 Exercise price (CHF) 43.80 Expected term of the award on the grant date (years) (2) 6 Expected volatility of the share price (3) 75 % Risk-free interest rate (4) 1 % Expected dividend rate — Grant date 10/25/2021 Estimated fair value of the option on the grant date using Black-Scholes model (USD) (5) 336.30 Exercise price (CHF) 0.10 Expected term of the award on the grant date (years) (2) 6 Expected volatility of the share price (3) 75 % Risk-free interest rate (4) 1 % Expected dividend rate — _________________ (1) The Company assumed a fair value per Common Share of USD 49 when estimating the fair value of the option. The fair value per Common Share was determined with reference to the market-based transaction with the other Series A Preferred Shares Investors (refer Note 9 of the financial statements for the Period from March 30, 2021 to December 31, 2021). (2) The expected term represents the period that share-based awards are expected to be outstanding. (3) The expected volatility was derived from the historical stock volatilities of comparable peer public companies within the Company’s industry. (4) The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the measurement date with maturities approximately equal to the expected term. (5) The Company estimated the fair value of the Common Shares by dividing the Company Enterprise Value (USD 360,000,000) as defined by the Business Combination Agreement by the Company’s fully diluted shares (1,070,196) Weighted average assumptions for the awards issued during the year ended December 31, 2022 Grant dates 5/1/2022, 6/22/2022 Estimated fair value of the option on the grant date using Black-Scholes model ($) (1) 172.57 Exercise price (CHF) 27.25 Expected term of the award on the grant date (years) (2) 6 Expected volatility of the share price (3) 0.75 Risk-free interest rate (4) 3 % Expected dividend rate 0 _________________ (1) MoonLake AG estimated the fair value of the Common Shares multiplying the MoonLake Immunotherapeutics closing date trading share price on the grant date by the Exchange Ratio. (2) The expected term represents the period that share-based awards are expected to be outstanding. (3) The expected volatility was derived from the historical stock volatilities of comparable peer public companies within the Company’s industry. (4) The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the measurement date with maturities approximately equal to the expected term. Grant date 4/6/2022 Estimated fair value of the option on the grant date using Black-Scholes model ($) 8.25 Exercise price ($) 12.25 Expected term of the award on the grant date (years) 6 Expected volatility of the share price 75 % Risk-free interest rate 3 % Expected dividend rate -
Share-Based Payment Arrangement, Option, Activity	Grants awarded Program ESOP Awards outstanding at March 10, 2021 (Inception) — Awards granted for the period from March 10, 2021 to December 31, 2021 224,033 Awards outstanding at January 1, 2022 224,033 Awards granted for the year ended December 31, 2022 242,736 Awards outstanding at December 31, 2022 466,769 Awards exercisable at December 31, 2022 55,941 Grants awarded MoonLake Immunotherapeutics 2022 Equity Incentive Plan Program Awards outstanding at January 1, 2022 — Awards granted for the year ended December 31, 2022 180,000 Awards outstanding at December 31, 2022 180,000 Awards exercisable at December 31, 2022 —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The components of income or loss before income tax were as follows: Year Ended December 31, 2022 For the period from March 10, 2021 (Inception) to December 31, 2021 Switzerland $ (62,115,251) $ (53,663,726) Foreign (2,354,434) 24,866 Total $ (64,469,685) $ (53,638,860)
Schedule of Effective Income Tax Rate Reconciliation	The provision for income taxes differs from the amount computed by applying the statutory income tax rate to loss before income taxes as follows: Year Ended December 31, 2022 For the period from March 10, 2021 (Inception) to December 31, 2021 Statutory income tax rate 11.9 % 11.9 % Change in prior year estimates 0.1 % — % Change in valuation allowance (10.0) % (10.9) % Non-deductible expense (1.4) % (1.0) % Other (0.5) % 0.1 % Effective income tax rate 0.1 % 0.1 %
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets were: December 31, 2022 December 31, 2021 Intangible assets $ 4,492,435 $ 2,963,340 Defined benefit plan 33,451 8,497 Net operating loss carry forward 7,210,383 2,873,281 Total deferred tax assets (gross) 11,736,269 5,845,118 Valuation allowance (11,736,269) (5,845,118) Total deferred tax asset (net) $ — $ —

Business Combination Agreemen_3

Business Combination Agreement with Helix and Recapitalization - Narrative (Details)			10 Months Ended	12 Months Ended
	Apr. 05, 2022 USD ($) $ / shares shares	Oct. 04, 2021 USD ($) $ / shares shares	Dec. 31, 2021 USD ($)	Dec. 31, 2022 USD ($) $ / shares shares	Apr. 01, 2022 SFr / shares shares	Dec. 31, 2021 SFr / shares	Apr. 28, 2021 $ / shares
Schedule Of Reverse Recapitalization [Line Items]
Reverse recapitalization, net | $	$ 134,689,000
Repayments of loan liability | $	$ 15,000,000		$ 0	$ 15,000,000
Issuance of Class A ordinary shares upon business combination (in shares)				18,424,355
PIPE Investors
Schedule Of Reverse Recapitalization [Line Items]
Sale of stock (in shares)		11,600,000
Issuance price per share (USD per share) | $ / shares		$ 10
Net proceeds from the business combination | $		$ 116,000,000
IPO Private Placement Shares
Schedule Of Reverse Recapitalization [Line Items]
Sale of stock (in shares)		100,000
Aggregate fees | $		$ 1,000,000
Series A Preferred Shares
Schedule Of Reverse Recapitalization [Line Items]
Preferred stock, par value (CHF per share) | SFr / shares					SFr 0.10	SFr 0.10
Class V Voting Stock
Schedule Of Reverse Recapitalization [Line Items]
Common shares, shares authorized (in shares)					4,006,736
Common shares, par value (USD per share) | SFr / shares					SFr 0.01
Common stock, votes per share multiplier					10
Class B Ordinary Shares
Schedule Of Reverse Recapitalization [Line Items]
Common shares, par value (USD per share) | $ / shares	$ 0.0001
Conversion of stock, shares converted	2,875,000
Common stock, conversion ratio (in shares)	1
Class A Ordinary Shares
Schedule Of Reverse Recapitalization [Line Items]
Common shares, shares authorized (in shares)				500,000,000
Common shares, par value (USD per share) | $ / shares				$ 0.0001			$ 0.0001
Issuance of Class A ordinary shares upon business combination (in shares)	18,501,284
Preferred Shares purchased by a director following his appointment as chairman of the Board of Directors (in shares)	11,700,000
Sale of stock (in shares)		11,700,000
Class C Ordinary Shares
Schedule Of Reverse Recapitalization [Line Items]
Common shares, shares authorized (in shares)				100,000,000
Common shares, par value (USD per share) | $ / shares				$ 0.0001
Issuance of Helix Class C ordinary shares to ML parties (other than the BVF shareholders) (in shares)	15,775,472
Preferred Shares purchased by a director following his appointment as chairman of the Board of Directors (in shares)	15,775,472

Business Combination Agreemen_4

Business Combination Agreement with Helix and Recapitalization - Summary of Net Proceeds (Details) $ in Thousands	Apr. 05, 2022 USD ($)
Reverse Recapitalization [Abstract]
Investments held in Trust Account	$ 115,051
Less cash to cover redemptions of the Class A Ordinary Shares issued by Helix prior to the Closing Date	(80,842)
Plus PIPE investment	116,000
Less Helix transaction expense	(15,520)
of which accrued expenses	(5,798)
of which deferred IPO underwriting fee	(4,025)
of which other transaction expenses	(5,697)
Available Closing Date Cash	$ 134,689

Business Combination Agreemen_5

Business Combination Agreement with Helix and Recapitalization - Ordinary Shares Issued (Details) - shares			10 Months Ended	12 Months Ended
	Apr. 05, 2022	Apr. 04, 2022	Dec. 31, 2021	Dec. 31, 2022
Schedule Of Reverse Recapitalization [Line Items]
Shares outstanding (in shares)	52,701,111
Less redemptions of class A ordinary shares of the class A ordinary shares issued by Helix prior to the closing date (in shares)			(1,942,837)
Plus issuance of helix class A ordinary shares to BVF shareholders (in shares)				18,424,355
Total MoonLake class A ordinary Shares outstanding at closing (in shares)			3,330,231
Class A Ordinary Shares
Schedule Of Reverse Recapitalization [Line Items]
Shares outstanding (in shares)				38,977,600
Plus issuance of Helix Class A Ordinary Shares to PIPE Investors (in shares)	11,700,000
Plus issuance of helix class A ordinary shares to BVF shareholders (in shares)	18,501,284
Total MoonLake class A ordinary Shares outstanding at closing (in shares)	36,925,639
Class C Ordinary Shares
Schedule Of Reverse Recapitalization [Line Items]
Shares outstanding (in shares)				13,723,511
Plus issuance of Helix Class A Ordinary Shares to PIPE Investors (in shares)	15,775,472
Issuance of Helix Class C ordinary shares to ML parties (other than the BVF shareholders) (in shares)	15,775,472
Helix Acquisition Corp.
Schedule Of Reverse Recapitalization [Line Items]
Shares outstanding (in shares)		14,805,000
Helix Acquisition Corp. | Class A Ordinary Shares
Schedule Of Reverse Recapitalization [Line Items]
Less redemptions of class A ordinary shares of the class A ordinary shares issued by Helix prior to the closing date (in shares)		(8,080,645)
Helix Acquisition Corp. | Common class A, private placement
Schedule Of Reverse Recapitalization [Line Items]
Shares outstanding (in shares)		430,000
Helix Acquisition Corp. | Common class A, redeemable
Schedule Of Reverse Recapitalization [Line Items]
Shares outstanding (in shares)		11,500,000
Helix Acquisition Corp. | Class B Ordinary Shares
Schedule Of Reverse Recapitalization [Line Items]
Shares outstanding (in shares)		2,875,000

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Details)		12 Months Ended
	Apr. 05, 2022 shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($)	Dec. 31, 2022 CHF (SFr)	Dec. 31, 2022 USD ($)
Class of Stock [Line Items]
Exchange ratio	33.638698
Debt securities, available-for-sale | $					$ 52,490,507
Cash, FDIC Insured Amount | SFr				SFr 100,000
Foreign currency transaction gain (loss) | $		$ 325,317	$ (59,660)
Issuance of Class A ordinary shares upon business combination (in shares)		18,424,355
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other income (expense), net
Of which classified within cash and cash equivalents
Class of Stock [Line Items]
Debt securities, available-for-sale | $					$ 19,881,399
Minimum
Class of Stock [Line Items]
Property and equipment, useful life		3 years
Maximum
Class of Stock [Line Items]
Property and equipment, useful life		5 years
Class A Ordinary Shares
Class of Stock [Line Items]
Preferred Shares purchased by a director following his appointment as chairman of the Board of Directors (in shares)	11,700,000
Issuance of Class A ordinary shares upon business combination (in shares)	18,501,284
Class C Ordinary Shares
Class of Stock [Line Items]
Preferred Shares purchased by a director following his appointment as chairman of the Board of Directors (in shares)	15,775,472

Risks and Liquidity (Details)

Risks and Liquidity (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Risks and Uncertainties [Abstract]
Net loss	$ (53,643,615)	$ (64,506,051)
Excess of current assets less current liabilities		68,800,000
Unrestricted cash		39,500,000
Debt securities, available-for-sale		52,490,507
Short-term marketable debt securities	$ 0	$ 32,609,108

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	$ 32,609,108	$ 0
Total	52,490,507
Eurocommercial Papers
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	42,552,608
Certificates of Deposit
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	9,937,899
Level 1
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Total	0
Level 1 | Eurocommercial Papers
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	0
Level 1 | Certificates of Deposit
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	0
Level 2
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Total	52,490,507
Level 2 | Eurocommercial Papers
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	42,552,608
Level 2 | Certificates of Deposit
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	9,937,899
Level 3
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Total	0
Level 3 | Eurocommercial Papers
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	0
Level 3 | Certificates of Deposit
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Short-term marketable debt securities	$ 0

Investments (Details)

Investments (Details)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	$ 52,099,754
Gross unrealized gains	390,753
Gross unrealized losses	0
Fair value	52,490,507
Of which classified within cash and cash equivalents
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	19,775,171
Gross unrealized gains	106,228
Gross unrealized losses	0
Fair value	19,881,399
Of which classified within short-term marketable debt securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	32,324,583
Gross unrealized gains	284,525
Gross unrealized losses	0
Fair value	32,609,108
Eurocommercial Papers
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	42,265,129
Gross unrealized gains	287,479
Gross unrealized losses	0
Fair value	42,552,608
Certificates of Deposit
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	9,834,625
Gross unrealized gains	103,274
Gross unrealized losses	0
Fair value	$ 9,937,899

Investments - FV changes (Detai

Investments - FV changes (Details) - Level 1	12 Months Ended
	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain (Loss) [Roll Forward]
Gross unrealized gain (loss), beginning balance	$ 0
Other comprehensive income before reclassifications	706,586
Amounts reclassified from accumulated other comprehensive income	(315,833)
Gross unrealized gain (loss), ending balance	$ 390,753

Prepaid Expenses (Details)

Prepaid Expenses (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Non-clinical research and clinical development services	$ 2,443,863	$ 547,586
Insurances	1,416,597	23,141
Other consulting and advisory services	105,651	31,930
Other prepayments	213,357	846,439
Total	$ 4,179,468	$ 1,449,096

Trade and Other Payables (Detai

Trade and Other Payables (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Supply and manufacturing fees payable	$ 65,979	$ 183,298
Other consulting and advisory services	51,658	71,938
Legal and intellectual property (“IP”) advisory fees payable	40,532	1,233,070
Research and development services	31,687	50,088
Other payables	65,116	30,896
Total	$ 254,972	$ 1,569,290

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Research and development services and license fees	$ 5,803,432	$ 2,055,687
Bonuses and related employees compensation expenses	1,109,734	1,419,137
Consultant and other fees	218,021	49,211
Tax liabilities	109,826	63,922
Legal fees	15,832	930,354
Total	$ 7,256,845	$ 4,518,311

Accrued Expenses and Other Cu_4

Accrued Expenses and Other Current Liabilities - Narrative (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
Research and development	$ 35,529,331	$ 42,048,954
Phase 2 Clinical Trials
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
Research and development		$ 4,700,000

Leases - Future Lease Payments

Leases - Future Lease Payments (Details) - USD ($)	Dec. 31, 2022	Jan. 01, 2022	Dec. 31, 2021
Leases [Abstract]
2023	$ 155,300
2024	129,417
2025	0
2026	0
2027	0
Thereafter	0
Total lease payments	284,717
Less imputed interest	(2,137)
Total lease liability	282,580	$ 435,005
Less current portion of lease liability	153,629		$ 0
Long-term portion operating lease liability	$ 128,951		$ 0

Leases - Narrative (Details)

Leases - Narrative (Details)	1 Months Ended	12 Months Ended
	Aug. 31, 2021 ft²	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jan. 01, 2022 USD ($)
Leases [Abstract]
Square foot of leased space | ft²	2,300
Lessor, operating lease, term of contract	3 years
Lessee, operating lease, discount rate		0.80%
Short-term portion of operating lease liabilities		$ 153,629	$ 0
Lease expense		155,552	25,860
Operating lease right-of-use assets		282,580	$ 0	$ 435,005
Total lease liability		$ 282,580		$ 435,005

Employee Benefit Plans - Narrat

Employee Benefit Plans - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Service cost	$ 451,075	$ 143,467

Employee Benefit Plans - Change

Employee Benefit Plans - Changes in Summary of PBO And Plan Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning PBO	$ 1,322,874	$ 0
Service cost	451,075	143,467
Interest cost	5,056	0
Contributions by plan participants	138,243	64,954
Actuarial (gain) / losses	(374,317)	174,012
Transfers (in) / out	(204,695)	931,257
Foreign currency exchange rates changes	(16,267)	9,184
Ending PBO	1,321,969	1,322,874
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning fair value of plan assets	1,083,014	0
Actual return on plan assets	15,522	5,835
Return on plan assets above expected return	(115,877)	0
Contributions by the employer	138,243	73,448
Contributions by plan participants	138,243	64,954
Transfers (in) / out	(204,695)	931,257
Foreign currency exchange rates changes	(14,687)	7,520
Ending fair value of plan assets	$ 1,039,763	$ 1,083,014

Employee Benefit Plans - Amount

Employee Benefit Plans - Amounts Recorded on the Balance Sheet (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Fair value of plan assets	$ 1,039,763	$ 1,083,014
Present value of projected benefit obligation	(1,321,969)	(1,322,874)
Funded status	$ (282,206)	$ (239,860)

Employee Benefit Plans - Chan_2

Employee Benefit Plans - Changes in Pre-Tax AOCI (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Actuarial (gain) / loss - beginning of period	$ 168,177	$ 0
Actuarial (gain) / loss of current year / period	268,076	(168,177)
Amortization	(1,817)	0
Total	$ (101,716)	$ 168,177

Employee Benefit Plans - Assump

Employee Benefit Plans - Assumptions used to calculate liabilities (Details)	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Discount rate	2.20%	0.40%
Expected return on plan assets	3.80%	1.50%
Inflation	1.80%	1.10%
Long-term expected rate of salary increase	2.30%	1.60%

Employee Benefit Plans - Alloca

Employee Benefit Plans - Allocation Percentage (Details)	Dec. 31, 2022	Dec. 31, 2021
Equities
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined benefit plan, plan assets, actual allocation, percentage	34.11%	35.13%
Bonds
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined benefit plan, plan assets, actual allocation, percentage	28.89%	30.89%
Collateralized Mortgage-Backed Securities
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined benefit plan, plan assets, actual allocation, percentage	3.86%	3.83%
Liquidity
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined benefit plan, plan assets, actual allocation, percentage	2.41%	2.90%
Real estate
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined benefit plan, plan assets, actual allocation, percentage	27.17%	24.37%
Alternative investments
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined benefit plan, plan assets, actual allocation, percentage	3.40%	2.88%
Infrastructure
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined benefit plan, plan assets, actual allocation, percentage	0.16%	0%

Shareholders_ Equity (Deficit_2

Shareholders’ Equity (Deficit) - Schedule of Stock Authorized and Issued (Details)			10 Months Ended	12 Months Ended
	Oct. 06, 2022 shares	Apr. 05, 2022 shares	Dec. 31, 2021 SFr / shares shares	Dec. 31, 2022 SFr / shares shares	Dec. 31, 2022 $ / shares	Apr. 01, 2022 SFr / shares	Apr. 28, 2021 $ / shares
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Common Shares
Issuance of Class A Ordinary shares upon business combination (in shares)				600,000,000
Issuance of Class A ordinary shares upon business combination (in shares)				18,424,355
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Common Shares Held In Treasury
Share-based payment under the equity incentive plan ESPP (in shares)				1,177,354
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Total Number of Shares
Authorized, beginning balance (in shares)				36,000,000
Shares issued, beginning balance (in shares)				33,099,402
Share-based payment under the equity incentive plan ESPP (in shares)				1,177,354
Issuance of Class A Ordinary shares upon business combination (in shares)				600,000,000
Issuance of Class A ordinary shares upon business combination (in shares)				18,424,355
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Authorized, ending balance (in shares)			36,000,000	600,000,000
Shares issued, ending balance (in shares)			33,099,402	52,701,111
Conversion Of Shares Following Business Combination
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(36,000,000)
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(36,000,000)
Series A Preferred Shares
Series A Preferred Shares
Authorized, beginning balance (in shares)				22,880,908
Issued, beginning balance (in shares)				22,880,908
Authorized, ending balance (in shares)			22,880,908
Issued, ending balance (in shares)			22,880,908
Total Number of Shares
Series A Preferred Shares, par value (CHF per share) | SFr / shares			SFr 0.10			SFr 0.10
Class A Ordinary Shares
Common Shares
Issuance of Class A ordinary shares upon business combination (in shares)		18,501,284
Authorized, ending balance (in shares)				500,000,000
Issued, ending balance (in shares)				38,977,600
Total Number of Shares
Issuance of Class A ordinary shares upon business combination (in shares)		18,501,284
Common stock, par value (CHF/USD per share) | $ / shares					$ 0.0001		$ 0.0001
Class C Ordinary Shares
Common Shares
Authorized, ending balance (in shares)				100,000,000
Issued, ending balance (in shares)				13,723,511
Total Number of Shares
Common stock, par value (CHF/USD per share) | $ / shares					0.0001
Series A Preferred Shares
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
Series A Preferred Shares | Series A Preferred Shares
Series A Preferred Shares
Authorized, beginning balance (in shares)				22,880,908
Issued, beginning balance (in shares)				22,880,908
Authorized, ending balance (in shares)			22,880,908	0
Issued, ending balance (in shares)			22,880,908	0
Total Number of Shares
Series A Preferred Shares, par value (CHF per share) | SFr / shares				SFr 0.10
Series A Preferred Shares | Series A Preferred Shares | Conversion Of Shares Following Business Combination
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(22,880,908)
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(22,880,908)
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(22,880,908)
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(22,880,908)
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(22,880,908)
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(22,880,908)
Common Shares
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	(61,000)		19,207,697
Common Shares
Authorized, beginning balance (in shares)				13,119,092
Issued, beginning balance (in shares)				12,161,331
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	(61,000)		19,207,697
Authorized, ending balance (in shares)			13,119,092	0
Issued, ending balance (in shares)			12,161,331	0
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	(61,000)		19,207,697
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	(61,000)		19,207,697
Series A Preferred Shares, par value (CHF per share) | SFr / shares				SFr 0.10
Common Shares | Conversion Of Shares Following Business Combination
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(13,119,092)
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(12,161,331)
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(13,119,092)
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(12,161,331)
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(12,161,331)
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(12,161,331)
Common Shares | Class A Ordinary Shares
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961
Common Shares
Issuance of Class A Ordinary shares upon business combination (in shares)				500,000,000
Issuance of Class A ordinary shares upon business combination (in shares)				18,424,355
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961
Authorized, ending balance (in shares)				500,000,000
Issued, ending balance (in shares)				38,977,600
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961
Total Number of Shares
Issuance of Class A Ordinary shares upon business combination (in shares)				500,000,000
Issuance of Class A ordinary shares upon business combination (in shares)				18,424,355
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961
Common stock, par value (CHF/USD per share) | $ / shares					0.0001
Common Shares | Class A Ordinary Shares | Conversion Of Shares Following Business Combination
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				18,501,284
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				18,501,284
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				18,501,284
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				18,501,284
Common Shares | Class A Ordinary Shares | Conversion Of Class C into Class A
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				2,051,961
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				2,051,961
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				2,051,961
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				2,051,961
Common Shares | Class C Ordinary Shares
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961	15,775,472
Common Shares
Issuance of Class A Ordinary shares upon business combination (in shares)				100,000,000
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961	15,775,472
Authorized, ending balance (in shares)				100,000,000
Issued, ending balance (in shares)				13,723,511
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961	15,775,472
Total Number of Shares
Issuance of Class A Ordinary shares upon business combination (in shares)				100,000,000
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961	15,775,472
Common stock, par value (CHF/USD per share) | $ / shares					$ 0.0001
Common Shares | Class C Ordinary Shares | Conversion Of Shares Following Business Combination
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				15,775,472
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				15,775,472
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				15,775,472
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				15,775,472
Common Shares | Class C Ordinary Shares | Conversion Of Class C into Class A
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(2,051,961)
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(2,051,961)
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(2,051,961)
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				(2,051,961)
Common Shares Held In Treasury
Common Shares Held In Treasury
Held in Treasury, beginning balance (in shares)				(1,942,837)
Share-based payment under the equity incentive plan ESPP (in shares)				1,177,354
Held in Treasury, ending balance (in shares)			(1,942,837)	0
Total Number of Shares
Share-based payment under the equity incentive plan ESPP (in shares)				1,177,354
Common stock, par value (CHF/USD per share) | SFr / shares				SFr 0.10
Common Shares Held In Treasury | Conversion Of Shares Following Business Combination
Series A Preferred Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				765,483
Common Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				765,483
Common Shares Held In Treasury
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				765,483
Total Number of Shares
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)				765,483

Shareholders_ Equity (Deficit_3

Shareholders’ Equity (Deficit) - Narrative (Details)			10 Months Ended
	Oct. 06, 2022 shares	Apr. 05, 2022 shares	Dec. 31, 2021 shares	Dec. 31, 2022 vote $ / shares shares	Apr. 28, 2021 $ / shares	Mar. 09, 2021 shares
Class of Stock [Line Items]
Common Shares, shares outstanding (in shares)		52,701,111
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)			19,207,697
ML parties other than BVF shareholders
Class of Stock [Line Items]
MoonLake AG common shares (in shares)		468,968		407,968
Common Shares
Class of Stock [Line Items]
Common Shares, shares issued (in shares)			12,161,331	0
Common Shares, shares outstanding (in shares)			12,161,331			33,638,698
Common shares, shares authorized (in shares)			13,119,092	0
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	(61,000)		19,207,697
Class A Ordinary Shares
Class of Stock [Line Items]
Common Shares, shares issued (in shares)				38,977,600
Common Shares, shares outstanding (in shares)				38,977,600
Common shares, shares authorized (in shares)				500,000,000
Common shares, par value (USD per share) | $ / shares				$ 0.0001	$ 0.0001
Class A Ordinary Shares | Common Shares
Class of Stock [Line Items]
Common Shares, shares issued (in shares)				38,977,600
Common Shares, shares outstanding (in shares)				38,977,600
Common shares, shares authorized (in shares)				500,000,000
Common shares, par value (USD per share) | $ / shares				$ 0.0001
Common Shares, votes per share | vote				1
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961
Class C Ordinary Shares
Class of Stock [Line Items]
Common Shares, shares issued (in shares)				13,723,511
Common Shares, shares outstanding (in shares)				13,723,511
Common shares, shares authorized (in shares)				100,000,000
Common shares, par value (USD per share) | $ / shares				$ 0.0001
Class C Ordinary Shares | Common Shares
Class of Stock [Line Items]
Common Shares, shares issued (in shares)				13,723,511
Common Shares, shares outstanding (in shares)				13,723,511
Common shares, shares authorized (in shares)				100,000,000
Common shares, par value (USD per share) | $ / shares				$ 0.0001
Common Shares, votes per share | vote				1
Conversion of MoonLake AG shares into class A ordinary shares and class C ordinary shares following the business combination (in shares)	2,051,961	15,775,472

Net loss per share - Calculatio

Net loss per share - Calculation of Net Loss per Share (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Numerator
Net loss attributable to controlling interests shareholders	$ (53,643,615)	$ (49,973,249)
Denominator
Total weighted average number of outstanding shares, basic (in shares)	7,840,707	29,361,353
Total weighted average number of outstanding shares, diluted (in shares)	7,840,707	29,361,353
Net loss per share - basic (in USD per share)	$ (6.84)	$ (1.70)
Net loss per share - diluted (in USD per share)	$ (6.84)	$ (1.70)

Net loss per share - Narrative

Net loss per share - Narrative (Details) - $ / shares		10 Months Ended	12 Months Ended
	Apr. 05, 2022	Dec. 31, 2021	Dec. 31, 2022	Mar. 20, 2023	Mar. 09, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average number of shares, basic (in shares)		7,840,707	29,361,353
Weighted-average number of shares, diluted (in shares)		7,840,707	29,361,353
Net loss per share - basic (in USD per share)		$ (6.84)	$ (1.70)
Net loss per share - diluted (in USD per share)		$ (6.84)	$ (1.70)
Number of shares outstanding (in shares)	52,701,111
Pro forma
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average number of shares, basic (in shares)			40,547,405
Weighted-average number of shares, diluted (in shares)			40,547,405
Net loss per share - basic (in USD per share)			$ (1.59)
Net loss per share - diluted (in USD per share)			$ (1.59)
Number of shares outstanding (in shares)				52,701,111
MoonLake AG Common Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common Shares, shares issued (in shares)		12,161,331	0
Number of shares outstanding (in shares)		12,161,331			33,638,698
ML parties other than BVF shareholders
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
MoonLake AG common shares (in shares)	468,968		407,968
Class C Ordinary Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common Shares, shares issued (in shares)			13,723,511
Stock converted (in shares)	15,775,472
Number of shares outstanding (in shares)			13,723,511
Class C Ordinary Shares | MoonLake AG Common Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common Shares, shares issued (in shares)			13,723,511
Number of shares outstanding (in shares)			13,723,511
Class A Ordinary Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common Shares, shares issued (in shares)			38,977,600
Weighted-average number of shares, basic (in shares)		0	29,361,353
Weighted-average number of shares, diluted (in shares)		0	29,361,353
Net loss per share - basic (in USD per share)		$ 0	$ (1.70)
Net loss per share - diluted (in USD per share)		$ 0	$ (1.70)
Number of shares outstanding (in shares)			38,977,600
Class A Ordinary Shares | MoonLake AG Common Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common Shares, shares issued (in shares)			38,977,600
Number of shares outstanding (in shares)			38,977,600
Class A Ordinary Shares | ML parties other than BVF shareholders | Pro forma
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock converted (in shares)			13,723,511

Share-based Compensation - Narr

Share-based Compensation - Narrative (Details)				10 Months Ended	12 Months Ended
	Apr. 06, 2022 shares	Apr. 05, 2022 shares	Apr. 28, 2021 SFr / shares shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2022 USD ($) $ / shares shares	Apr. 28, 2021 $ / shares shares	Mar. 09, 2021 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense | $				$ 9,052,909	$ 9,654,778
Common Shares, shares outstanding (in shares)		52,701,111
MoonLake AG Common Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares issuable (in shares)					14,596
Common Shares, shares outstanding (in shares)				12,161,331			33,638,698
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense | $				$ 0	$ 364,381
Weighted average period of recognition					2 years 3 months 7 days
Expiration period		10 years
Estimated fair value of the option on the grant date using Black-Scholes model (in shares)	180,000				180,000
Unrecognized compensation expense | $					$ 1,100,000
Equity Incentive Plan | Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage	33.33%
Equity Incentive Plan | Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage	33.33%
Equity Incentive Plan | Share-Based Payment Arrangement, Tranche Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage	33.33%
Employee Stock Option Plan (ESOP)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unrecognized compensation expense, options | $					1,800,000
MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense | $				8,837,092	4,840,608
Unrecognized share-based compensation expense, non-option awards | $					1,600,000
Monthly SBP expense | $					403,361
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense | $				148,835	3,910,076
Unrecognized share-based compensation expense, non-option awards | $					$ 9,500,000
Vesting period after occurrence of change of control					12 months
Weighted average period of recognition					1 year 9 months 7 days
ESPP | Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESPP | Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESPP | Share-Based Payment Arrangement, Tranche Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESPP | Share-Based Payment Arrangement, Tranche Four
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
ESPP | Employee Stock Option Plan (ESOP)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted average period of recognition					2 years 7 months 20 days
Research and development services
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense | $				$ 66,982	$ 539,713
Research and development services | Employee Stock Option Plan (ESOP)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period after occurrence of change of control					12 months
Estimated fair value of the option on the grant date using Black-Scholes model (in shares)				224,033	242,736
Research and development services | Employee Stock Option Plan (ESOP) | Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
Research and development services | Employee Stock Option Plan (ESOP) | Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
Research and development services | Employee Stock Option Plan (ESOP) | Share-Based Payment Arrangement, Tranche Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
Research and development services | Employee Stock Option Plan (ESOP) | Share-Based Payment Arrangement, Tranche Four
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percentage					25%
Option and employee stock | Treasury Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares issuable (in shares)					22,756
Class C Ordinary Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)					13,723,511
Common shares, par value (USD per share) | $ / shares					$ 0.0001
Class C Ordinary Shares | MoonLake AG Common Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares issuable (in shares)					490,990
Common Shares, shares outstanding (in shares)					13,723,511
Common shares, par value (USD per share) | $ / shares					$ 0.0001
Class C Ordinary Shares | Option and employee stock | Treasury Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common shares issuable (in shares)					765,482
Class A Ordinary Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)					38,977,600
Common shares, par value (USD per share) | $ / shares					$ 0.0001	$ 0.0001
Class A Ordinary Shares | MoonLake AG Common Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)					38,977,600
Common shares, par value (USD per share) | $ / shares					$ 0.0001
MoonLake AG
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Reverse vesting percentage			90%			90%
Common Shares, shares outstanding (in shares)			110,000			110,000
MoonLake AG | MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)			99,000			99,000
Vesting percentage			4.166%
Vesting period			2 years
Nominal value (CHF per share) | SFr / shares			SFr 0.10
MoonLake AG | Class C Ordinary Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)			3,700,257			3,700,257
MoonLake AG | Class C Ordinary Shares | MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)			3,330,231			3,330,231

Share-based Compensation - Shar

Share-based Compensation - Share-based Compensation Expense By Plan (Details) - USD ($)		10 Months Ended	12 Months Ended
	Apr. 28, 2021	Dec. 31, 2021	Dec. 31, 2022	Apr. 05, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense		$ 9,052,909	$ 9,654,778
Common Shares, shares outstanding (in shares)				52,701,111
MoonLake AG
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)	110,000
Merck KGaA Darmstadt in-licensing agreement
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Cash consideration	$ 25,000,000
Equity consideration	99,000
Total payment	$ 1
Fair value of the equity consideration	$ 4,851,000
Class C Ordinary Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)			13,723,511
Class C Ordinary Shares | MoonLake AG
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)	3,700,257
Research and Development Expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense		72,183	$ 954,379
General and Administrative Expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense		8,980,726	8,700,399
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense		0	364,381
MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense		8,837,092	4,840,608
MoonLake AG Restricted Founder Shares | MoonLake AG
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)	99,000
MoonLake AG Restricted Founder Shares | Class C Ordinary Shares | MoonLake AG
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common Shares, shares outstanding (in shares)	3,330,231
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense		148,835	3,910,076
Research and development services
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation expense		$ 66,982	$ 539,713

Share-based Compensation - Assu

Share-based Compensation - Assumptions (Details)					10 Months Ended	12 Months Ended
	Apr. 06, 2022 $ / shares shares	Oct. 25, 2021 SFr / shares $ / shares	Sep. 09, 2021 $ / shares SFr / shares	Jul. 27, 2021 SFr / shares $ / shares	Dec. 31, 2021 shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2022 SFr / shares shares	Mar. 31, 2022 shares	Mar. 10, 2021 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Enterprise value | $						$ 360,000,000	$ 360,000,000
Fully diluted shares (in shares) | shares						1,070,196	1,070,196
MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Estimated fair value per share of Restricted Founder Shares on the grant date (in dollars per share)						$ 49
Estimated fair value of Restricted Founder Shares on the resignation date of one of the co-founders of MoonLake AG (in dollars per share)						336.39
Purchase price (in CHF per share) | SFr / shares								SFr 0.1
Awards outstanding (in shares) | shares					4,440,309		4,440,309	1,110,078		0
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Estimated fair value per share of Restricted Founder Shares on the grant date (in dollars per share)		$ 336.39	$ 49	$ 49		$ 336.39
Purchase price (in CHF per share) | SFr / shares		$ 0.1	$ 0.1	$ 0.1				SFr 0.1
Awards outstanding (in shares) | shares					1,060,561		1,060,561	2,237,915	2,237,915	0
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Estimated fair value of the option on the grant date using Black-Scholes model (in shares) | shares	180,000					180,000
Estimated fair value of the option on the grant date using Black-Scholes model (in dollars per share)	$ 8.25
Exercise price (in dollars per share)	$ 12.25
Expected term of the award	6 years
Expected volatility of the share price	75%
Risk-free interest rate	3%
Expected dividend rate	0%
Employee Stock Option Plan (ESOP) | Research and development services
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Estimated fair value of the option on the grant date using Black-Scholes model (in shares) | shares					224,033	242,736
Estimated fair value of the option on the grant date using Black-Scholes model (in dollars per share)		$ 336.30	$ 32.93			$ 172.57
Exercise price (in dollars per share) | SFr / shares		$ 0.10	$ 43.80					SFr 27.25
Expected term of the award		6 years	6 years			6 years
Expected volatility of the share price		75%	75%			75%
Risk-free interest rate		1%	1%			3%
Expected dividend rate		0%	0%			0%

Share-based Compensation - Awar

Share-based Compensation - Awarded and Granted (Details) - shares		3 Months Ended	6 Months Ended	10 Months Ended	12 Months Ended
	Apr. 06, 2022	Mar. 31, 2022	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2022
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Awards outstanding beginning balance (in shares)		0	0		0
Estimated fair value of the option on the grant date using Black-Scholes model (in shares)	180,000				180,000
Awards outstanding ending balance (in shares)				0	180,000
Awards exercisable (in shares)					0
MoonLake AG Restricted Founder Shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Awards outstanding, beginning balance (in shares)		4,440,309	4,440,309		4,440,309
Awards granted (in shares)				9,990,694
Awards repurchases (in shares)				(1,942,837)
Awards vested (in shares)				(3,607,548)	(3,330,231)
Awards outstanding, ending balance (in shares)				4,440,309	1,110,078
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Awards outstanding, beginning balance (in shares)		1,060,561	1,060,561		1,060,561
Awards granted (in shares)		1,177,354	0	1,060,561	1,177,354
Awards vested (in shares)					(307,794)
Awards outstanding, ending balance (in shares)		2,237,915		1,060,561	2,237,915
Research and development services | Employee Stock Option Plan (ESOP)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Awards outstanding beginning balance (in shares)		224,033	224,033	0	224,033
Estimated fair value of the option on the grant date using Black-Scholes model (in shares)				224,033	242,736
Awards outstanding ending balance (in shares)				224,033	466,769
Awards exercisable (in shares)					55,941

Income taxes - Narrative (Detai

Income taxes - Narrative (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Effective income tax rate	0.10%	0.10%	(0.10%)
Deferred tax assets, gross	$ 5,845,118	$ 11,736,269	$ 5,845,118
Valuation allowance	$ 5,845,118	11,736,269	$ 5,845,118
Operating loss carryforwards		60,800,000
Expiration in 2028
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		14,900,000
Expiration in 2029
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		$ 45,900,000

Income taxes - Summary of Net I

Income taxes - Summary of Net Income (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Switzerland	$ (53,663,726)	$ (62,115,251)
Foreign	24,866	(2,354,434)
Income (loss) attributable to parent, before tax	$ (53,638,860)	$ (64,469,685)

Income taxes- Statutory Tax Per

Income taxes- Statutory Tax Percent (Details)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Statutory income tax rate	11.90%	11.90%
Change in prior year estimates	0%	0.10%
Change in valuation allowance	(10.90%)	(10.00%)
Non-deductible expense	(1.00%)	(1.40%)
Other	0.10%	(0.50%)
Effective income tax rate	0.10%	0.10%	(0.10%)

Income taxes - Summary of Defer

Income taxes - Summary of Deferred Tax (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Intangible assets	$ 4,492,435	$ 2,963,340
Defined benefit plan	33,451	8,497
Net operating loss carry forward	7,210,383	2,873,281
Total deferred tax assets (gross)	11,736,269	5,845,118
Valuation allowance	(11,736,269)	(5,845,118)
Total deferred tax asset (net)	$ 0	$ 0

Commitment and Contingencies (D

Commitment and Contingencies (Details) - Dec. 31, 2022 € in Millions, $ in Millions	USD ($)	EUR (€)
Other Commitments [Line Items]
Total commitments not yet recognized	$ 31.9
License | SLK Program
Other Commitments [Line Items]
Variable consideration amount	$ 319.5	€ 299.6

Related Party Transactions (Det

Related Party Transactions (Details) - Affiliated Entity	Oct. 15, 2021 USD ($)
Related Party Transaction [Line Items]
Loan agreement	$ 15,000,000
Biotechnology Value Fund, L.P
Related Party Transaction [Line Items]
Loan agreement	8,139,000
Biotechnology Value Fund II, L.P
Related Party Transaction [Line Items]
Loan agreement	5,946,000
Biotechnology Value Trading Fund OS, L.P
Related Party Transaction [Line Items]
Loan agreement	$ 915,000

Subsequent Events (Details)

Subsequent Events (Details) - shares				10 Months Ended
	Feb. 16, 2023	Oct. 06, 2022	Apr. 05, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Conversion and transfer of shares between classes (in shares)				19,207,697
MoonLake AG Common Shares
Subsequent Event [Line Items]
Conversion and transfer of shares between classes (in shares)		(61,000)		19,207,697
MoonLake AG Common Shares | Subsequent Event
Subsequent Event [Line Items]
Conversion and transfer of shares between classes (in shares)	5,250
MoonLake AG Common Shares | Class C Ordinary Shares
Subsequent Event [Line Items]
Conversion and transfer of shares between classes (in shares)		2,051,961	15,775,472
MoonLake AG Common Shares | Class C Ordinary Shares | Subsequent Event
Subsequent Event [Line Items]
Conversion and transfer of shares between classes (in shares)	176,603
MoonLake AG Common Shares | Class A Ordinary Shares
Subsequent Event [Line Items]
Conversion and transfer of shares between classes (in shares)		2,051,961
MoonLake AG Common Shares | Class A Ordinary Shares | Subsequent Event
Subsequent Event [Line Items]
Conversion and transfer of shares between classes (in shares)	176,603