UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 17, 2025

SHUTTLE PHARMACEUTICALS HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

401 Professional Drive, Suite 260

Gaithersburg, MD 20879

(Address of principal executive offices) (Zip Code)

(240) 430-4212

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

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 with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Shuttle Pharmaceuticals Holdings, Inc. (the “Company”) reported stockholders’ equity of $1,394,161 in its Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2025, and, as a result, was not in compliance with Nasdaq Listing Rule 5550(b)(1), which requires companies listed on the Nasdaq Capital Market (“Nasdaq”) to maintain a minimum of $2,500,000 in stockholders’ equity for continued listing (the “Stockholders’ Equity Requirement”). The Company believes that, as of the date of this Current Report on Form 8-K (this “Form 8-K”), it has regained compliance with the Stockholders’ Equity Requirement based upon the Company’s private placement consummated on November 4, 2025, pursuant to which the Company raised aggregate gross proceeds of approximately $2.5 million, before deducting placement agent fees and offering expenses payable by the Company. The Nasdaq Listing Qualifications staff will continue to monitor the Company’s ongoing compliance with the Stockholders’ Equity Requirement and, if at the time of the Company’s next periodic report the Company does not evidence compliance with Listing Rule 5550(b)(1), the Company may be subject to delisting.

Cautionary Statement Regarding Forward-Looking Statements

This Form 8-K contains forward-looking statements within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. Forward-looking statements include, but are not limited to, statements that express the Company’s intentions, beliefs, expectations, strategies, predictions or any other statements related to the Company’s future activities, or future events or conditions, including those related to the Company’s compliance with the Stockholders’ Equity Requirement, which can be identified by terminology such as “may,” “will,” “expects,” “anticipates,” “aims,” “potential,” “future,” “intends,” “plans,” “believes,” “estimates,” “continue,” “likely to” and other similar expressions intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These statements are not historical facts and are based on current expectations, estimates and projections about the Company’s business based, in part, on assumptions made by its management. These statements are not guarantees of future performance and involve risks, uncertainties and assumptions that are difficult to predict, many of which are beyond the Company’s control, including, among other things, volatility in the market price of the Company’s common stock, the Company’s ability to manage costs and execute on its operational and budget plans, risks related to general market, economic and other conditions, the Company’s ability to maintain the listing of its common stock on Nasdaq, and those other risks that may be included in the periodic reports and other filings that the Company files from time to time with the U.S. Securities and Exchange Commission, which may cause the Company’s actual results, performance and achievements to differ materially from those contained in any forward-looking statement. Any forward-looking statements speak only as of the date on which they are made, and the Company undertakes no obligation to update any forward-looking statement to reflect events or circumstances after the date of this Form 8-K, except as required by applicable law.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.