Company Update

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 17, 2025   Tenax Therapeutics, Inc. (Exact name of registrant as specified in its charter)   Delaware   001-34600   26-2593535 (State or other jurisdiction of incorporation)   (Commission File Number)   (IRS Employer Identification No.)   101 Glen Lennox Drive , Suite 300 Chapel Hill , NC 27517 (Address of principal executive offices) (Zip Code)   919 - 855-2100 (Registrant’s telephone number, including area code)   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, $0.0001 par value per share TENX 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 (17 CFR 230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR 240.12b-2).   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 17, 2025, Tenax Therapeutics, Inc. (the “Company”) issued a press release announcing that the prespecified Blinded Sample Size Re-estimation (BSSR) of LEVEL, an ongoing, registrational Phase 3 clinical trial evaluating TNX-103 (oral levosimendan) in patients with pulmonary hypertension in heart failure with preserved ejection fraction (PH-HFpEF) in the United States and Canada, demonstrated the trial is powered at well over 90% to detect a 25 meter change in 6-minute walk distance (6MWD), the primary endpoint. Based on these results, Tenax confirmed the previously announced target enrollment number and expected enrollment completion timeframe as well as topline data timeframe. The Company also announced that it has initiated its global Phase 3 LEVEL-2 study, the second registrational Phase 3 study of TNX-103 in patients with PH-HFpEF. A copy of the press release is attached hereto as Exhibit 99.1.   Item 9.01 Financial Statements and Exhibits.   (d) Exhibits   Exhibit No.   Description       99.1 Press Release dated December 17, 2025. 104   Cover Page Interactive Data File (embedded within the Inline XBRL document).     2     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.   Date: December 17, 2025 Tenax Therapeutics, Inc.             By: /s/ Christopher T. Giordano       Christopher T. Giordano       President and Chief Executive Officer       3