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): December 2, 2025

ASP Isotopes Inc.

(Exact name of registrant as specified in its charter)

Delaware

001-41555

87-2618235

(State or other jurisdiction of

incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

601 Pennsylvania Avenue NW,

South Building, Suite 900

Washington, DC

20004

(Address of principal executive offices)

(Zip Code)

Registrant’s telephone number, including area code: (202) 756-2245

Not Applicable

(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:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, par value $0.01		ASPI		The Nasdaq Stock Market LLC

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 ☐

Item 8.01. Other Events.

On December 2, 2025, ASP Isotopes Inc. (the “Company”) issued a press release announcing Paul Mann the founder and Executive Chairman of the Company, will resume his role as the Company’s Chief Executive Officer and continue as Executive Chairman, effective January 19, 2026, after a temporary leave of absence. A copy of the press release is attached to this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference, other than the fourth paragraph of the press release.

Item 9.01. Financial Statements and Exhibits.

Exhibit No.		Description
99.1		Press Release, dated December 2, 2025, of ASP Isotopes Inc. announcing Paul Mann to return from temporary leave of absence as Executive Chairman and Chief Executive Officer.
104		Cover Page Interactive Date File (embedded within the Inline XBRL document)

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.

	ASP ISOTOPES INC.

Date: December 2, 2025	By:	/s/ Donald G. Ainscow
	Name:	Donald G. Ainscow
	Title:	Executive Vice President, General Counsel and Secretary

ASP Isotopes Inc. 8-K