Quoin Pharmaceuticals Ltd ADR美股招股说明书(2026-06-02版)

This Prospectus Supplement No. 1 supplements the prospectus dated December 4, 2025 (the “Prospectus”) relating to the resale fromtime to time of up to 10,045,455 American Depositary Shares (“ADSs”) representing 351,590,925 ordinary shares, no par value pershare of Quoin Pharmaceuticals Ltd.(the Company”) by the Selling Shareholders identified in the Prospectus (the “SellingShareholders”), including their pledgees, assignees or successors-in-interest. The purpose of this ProspectusSupplementNo. 1 is solely to update the information in the table appearing under the caption “SellingShareholders” commencing on page 14 of the Prospectus to reflect in the Selling Shareholder table a transfer of warrants to purchaseup to an aggregate of 909,090 ADSs from Point72 Associates, LLC (“Point72”), a Selling Shareholder previously identified in theProspectus, to SILV Fund Ltd, another entity, which as a result of such transfer is being substituted as a Selling Shareholder. (1)The ADSs beneficially owned prior to this offering (which does not reflect the application of the Beneficial OwnershipLimitation)includes(i)181,818 Pre-Funded ADSs,(ii)181,818 Series H ADSs,(iii)181,818 Series I ADSs,(iv)181,818SeriesJ ADSs and (v)181,818SeriesK ADSs. Sirenia Capital Management LP (“Sirenia”) serves as theinvestment manager to SILV Fund, Ltd. and, as a result, maintains voting and investment power with respect to thesecurities held by SILV Fund, Ltd. Sirenia Capital Management GP LLC (“Sirenia GP”) is the general partner of Sirenia.Alex Silverstein is the managing member of Sirenia GP. Each of SILV Fund, Ltd., Sirenia GP and Mr. Silversteindisclaims beneficial ownership over such securities.The address of SILV Fund Ltd. is c/o Sirenia Capital ManagementLP, 1674 Meridian Avenue, Suite 320, Miami Beach, FL 33139. All of the other portions of the Prospectus remain unchanged. This Prospectus Supplement No. 1 is not complete without, and may not be utilized except in connection with, the Prospectus,including any amendments or supplements thereto. This Prospectus Supplement No. 1 is qualified by reference to the Prospectus,except to the extent that the information provided by this Prospectus Supplement No. 1 supersedes information contained in theProspectus. Capitalized terms used in this Prospectus Supplement No. 1 and not otherwise defined herein have the meanings specifiedin the Prospectus. Our ADSs are listed on the Nasdaq Capital Market under the symbol “QNRX”. On June 1, 2026, the closing price for our ADSs on theNasdaq Capital Market was $4.77 per ADS. Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you shouldconsider carefully the risks and uncertainties under the heading “Risk Factors” beginning on page 6 of the Prospectus and inour other filings with the SEC. Neither the SEC nor any state securities commission has approved or disapproved of these securities or passed upon theadequacy or accuracy of the Prospectus or this Prospectus Supplement No. 1. Any representation to the contrary is a criminaloffense. The date of this Prospectus Supplement No. 1 is June 2, 2026.