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 12, 2025

100 Spy Court

Markham, Ontario, Canada L3R 5H6

(Address of Principal Executive Offices)

(289) 800-9600

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 (see General Instruction A.2. below):

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. ☐

Item 8.01. Other Events.

On December 12, 2025, Edesa Biotech, Inc. (the “Company”), filed a prospectus supplement (the “Prospectus Supplement”) with the U.S. Securities and Exchange Commission (the “SEC”) to increase the maximum aggregate offering amount of the Company’s common shares, without par value (the “Common Shares”), issuable under the At The Market Offering Agreement (the “ATM Agreement”) with H.C. Wainwright & Co., LLC, dated October 4, 2024, to $2,262,508. The Prospectus Supplement amends and supplements the information contained in the prospectus, dated September 9, 2025 (the “Base Prospectus”), filed as part of the Company’s registration statement on Form S-3 (File No. 333-288966), as supplemented by the prospectus supplement dated September 9, 2025 (the “Prior Prospectus”).

As of the date hereof, pursuant to the ATM Agreement, the Company has sold an aggregate of $3,718,324.61 of Common Shares pursuant to the Prior Prospectus to date and an aggregate of $837,134 of Common Shares pursuant to the prospectus supplement, dated October 4, 2024 to the Company’s Registration Statement on Form S-3 (333-266604).

Fasken Martineau DuMoulin LLP, counsel to the Company, has issued a legal opinion relating to the validity of the $2,262,508 Common Shares that may be offered and sold pursuant to the ATM Agreement and related Prospectus Supplement. A copy of such legal opinion, including the consent included therein, is attached as Exhibit 5.1 to this Current Report on Form 8-K.

This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of an offer to buy the Common Shares discussed herein, nor shall there be any sale of such securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

The following exhibits are furnished with this Current Report on Form 8-K:

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.