8-K

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): August 28, 2025

PROPHASE

LABS, INC.

(Exact name of Company as specified in its charter)

Registrant’s telephone number, including area code: (516) 989-0763

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the Company under any of the following provisions (see General Instruction A.2. below):

Securities Registered Pursuant to Section 12(b) of the Exchange 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. ☐

Item1.02. Termination of a Material Definitive Agreement.

On August 27, 2025, ProPhase Labs, Inc. (the “Company”) delivered notice to Keystone Capital Partners, LLC (“Keystone”) to terminate, effective the next trading day, the Common Stock Purchase Agreement dated January 29, 2025, between the Company and Keystone (the “Keystone Agreement”). Pursuant to such notice, the Keystone Agreement terminated effectively on Thursday, August 28, 2025.

The Keystone Agreement established an equity line of credit facility under which the Company had the right, but not the obligation, to sell shares of its common stock to Keystone up to an aggregate purchase price of approximately $7.7 million. The Keystone Agreement provided that the Company could terminate the facility at any time, in its sole discretion, upon one trading day’s prior written notice, without cost or penalty. The Company terminated the Keystone Agreement in its sole discretion and incurred no penalties or termination fees in connection with the termination. Other than the Keystone Agreement, there are no material relationships between the Company or its affiliates and Keystone.

Item9.01 Financial Statements and Exhibits.

(d) Exhibits

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

Date: August 28, 2025

Exhibit10.1

[August 27, 2025]

Keystone Capital Partners, LLC

139 Fulton Street, Suite 412

New York, NY 10038

Telephone Number: (646) 349-0916

Email: fz@keystone-cp.com

Attention: Fredric G. Zaino

Re: Termination of Common Stock Purchase Agreement

Ladies and Gentlemen:

Reference is made to the Common Stock Purchase Agreement (the “Agreement”) dated January 29, 2025, by and between ProPhase Labs, Inc. (the “Company”) and Keystone Capital Partners, LLC (“Keystone”). Pursuant to Section 7.2, Other Termination, of the Agreement, the Company hereby provides written notice of termination.

The termination shall be effective on the first trading day following the settlement of any pending purchase notices that have not yet fully settled as of the date hereof, and in any event no earlier than one trading day following the date of this notice.

Please confirm your receipt of this notice.