Allurion Technologies Inc美股招股说明书(2025-08-21版)

ALLURION TECHNOLOGIES, INC. Up to 56,548,268 Shares of Common Stock This prospectus supplement no. 27 (this “Prospectus Supplement”) amends and supplements the prospectus dated December15, 2023 (as supplementedor amended from time to time, the “Prospectus”) which forms part of our Registration Statement on FormS-1/A(Registration StatementNo.333-274564).This Prospectus Supplement is being filed to update and supplement the information included or incorporated by reference in theProspectus with the information contained in our Amended Quarterly Report on Form10-Q,filed with the Securities and Exchange Commission (the“SEC”) on August19, 2025 (the“10-Q/A”).Accordingly, we have attached the10-Q/Ato this Prospectus Supplement. This Prospectus Supplement updates and supplements the information in the Prospectus and is not complete without, and may not be delivered orutilized except in combination with, the Prospectus, including any amendments or supplements thereto. This Prospectus Supplement should be read inconjunction with the Prospectus, and if there is any inconsistency between the information in the Prospectus and this Prospectus Supplement, you shouldrely on this Prospectus Supplement. Our common stock is listed on The New York Stock Exchange (“NYSE”) under the symbol “ALUR” and our public warrants are listed on the NYSEunder the symbol “ALUR.WS”. On August20, 2025, the last quoted sale price for shares of our common stock as reported on the NYSE was $2.13 pershare, and the last quoted sale price for our public warrants as reported on the NYSE was $0.0314 per warrant. We are an “emerging growth company” under applicable federal securities laws and will be subject to reduced public company reportingrequirements. Investing in our securities involves a high degree of risk. Before buying any securities, you should carefully read thediscussion of the risks of investing in our securities in “Risk Factors” beginning on page26 of the Prospectus. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to beissued under the Prospectus or determined if the Prospectus is truthful or complete. Any representation to the contrary is a criminal offense. The date of this Prospectus Supplement is August21, 2025. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, DC 20549 (Mark One) QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGEACTOF1934 For the quarterly period ended March31, 2025 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGEACTOF1934 For the transition period from _________________ to _________________Commission File Number:001-41767 Allurion Technologies, Inc. (Exact Name of Registrant as Specified in its Charter) 92-2182207(I.R.S. EmployerIdentification No.) Delaware(State or other jurisdiction ofincorporation or organization) 11 Huron DriveNatick, MA(Address of principal executive offices) 01760(Zip Code) Securities registered pursuant to Section12(b) of the Act: TradingSymbol(s)ALURALUR WS Title of each classCommon Stock, par value $0.0001 per shareWarrants to purchase0.056818 shares of Common Stock for $202.50 per share Name of each exchange on which registeredThe New York Stock ExchangeThe New York Stock Exchange Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or 15(d) of the Securities Exchange Act of1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2)has been subject to suchfiling requirements for the past 90 days.Yes☒No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule405 of RegulationS-T(§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submitsuch files).Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-acceleratedfiler, smaller reporting company,or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growthcompany” in Rule12b-2of the Exchange Act. Largeacceleratedfiler☐Non-acceleratedfiler☒ Accelerated filer☐Smaller reporting company☒Emerging growth company☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying withany new or revised financial accounting standards provided pursuant to Section13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule12b-2of the Exchange Act).Yes☐No☒ As of May12, 2025, the registrant had 7,457,758 shares of common stock, $0.0001 par value per share, outstanding. Table of Contents EXPLANATORY NOTE This Amendment No.1 on Form10-Q