脑再生科技美股招股说明书(2026-05-19版)

985,222 Ordinary Shares This is an offering of 985,222 ordinary shares, par value $0.00001 per share, or Ordinary Shares, of Regencell BioscienceHoldings Limited (the “Company,” “we,” “us” or “our”) directly to certain investors pursuant to this prospectus supplement and theaccompanying prospectus and a securities purchase agreement dated as of May 19, 2026 by and among us and such investors (the“securities purchase agreement”) in a registered direct offering (this “offering”) at an offering price of $20.30 per Ordinary Share. Our Ordinary Shares trade on the Nasdaq Capital Market under the trading symbol “RGC.” On May 18, 2026, the last reportedclosing price of our Ordinary Shares on the Nasdaq Capital Market was $27.79 per Ordinary Share. We have engaged Univest Securities, LLC to act as the placement agent (“Univest” or the “Placement Agent”) to use its bestefforts to solicit offers from investors to purchase the securities in this offering. The Placement Agent is not obligated to purchase orsell any securities, nor is it required to arrange for the purchase or sale of any specific number or dollar amount of securities. See “Planof Distribution” beginning on page S-25 of this prospectus supplement for more information regarding these arrangements. We haveagreed to pay a cash compensation equal to six point five percent (6.5%) of the aggregate gross proceeds from the sale of the OrdinaryShares sold by the Placement Agent being offered hereby (the “Cash Fees”). We have also agreed to reimburse the Placement Agentfor its reasonable out-of-pocket actual expenses of up to $75,000 for all costs and expenses incurred. The Placement Agent has agreed to purchase 49,262 Ordinary Shares as principal for its own account, not as agent of theCompany, on the same terms as the other investors purchasing our Ordinary Shares in this offering for a total purchase price of $1million. Accordingly, the Placement Agent is acting in a dual capacity in connection with this offering, serving both as the exclusiveplacement agent for the sale of Ordinary Shares to third-party investors and as a direct purchaser of Ordinary Shares for its ownaccount. The Cash Fees payable to the Placement Agent are calculated on the basis of the aggregate gross proceeds received from thesale of Ordinary Shares to both third-party investors and the Placement Agent for its own account. PerOrdinaryShareTotalPublic offering price$20.3000$20,000,006.60Placement Agent fees(1)$1.3195$1,300,000.43Proceeds, before expenses, to us$18.9805$18,700,006.17 (1)See “Plan of Distribution” for additional information regarding total compensation payable to the Placement Agent, includingexpenses for which we have agreed to reimburse the Placement Agent. Investing in our Ordinary Shares involves a high degree of risk. See “Risk Factors” beginning on page S-12 of thisprospectussupplement and in the documents incorporated by reference into this prospectus supplement and theaccompanying prospectus for a discussion of certain risks that you should consider in connection with an investment in ourOrdinary Shares. We are an emerging growth company as that term is used in the Jumpstart Our Business Startups Act of 2012, and, as such, aresubject to certain reduced public company reporting requirements. See “Prospectus Supplement Summary — Implications of Being anEmerging Growth Company” on page S-10 of this prospectus supplement. We are a foreign private issuer within the meaning of the rules under the Securities Exchange Act of 1934, or the Exchange Act,and as such we are exempt from certain provisions of the securities rules and regulations in the United States that are applicable toU.S. domestic issuers, such as the rules regulating solicitation of proxies and certain insider reporting and short-swing profit rules.Moreover, the information we are required to file with or furnish to the SEC will be less extensive and less timely compared to thatrequired to be filed with the U.S. Securities and Exchange Commission, or the SEC, by U.S. domestic issuers. In addition, as acompany incorporated in the Cayman Islands, we are permitted to adopt certain home country practices in relation to corporategovernance matters that differ significantly from the corporate governance standards of Nasdaq. Neither the SEC nor any state securities commission nor any other regulatory body has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of this prospectus supplement, and those included in the accompanyingprospectus and the documents incorporated by reference. Any representation to the contrary is a criminal offense. The Ordinary Shares are expected to be delivered through the book-entry transfer facilities of The Depository Trust Company inNew York, New York on or about May 20, 2026, subject to customary closing conditions. Sole Placement Agent Univest Securities, LLC The date of this prospectus supplement is May 19, 2026 TABLE OF CONTENTS PROSPEC