SEC Form 424B3 filed by Medicus Pharma Ltd.

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-287599

PROSPECTUS SUPPLEMENT NO. 5

(to prospectus dated effective March 27, 2026)

Medicus Pharma Ltd.

3,245,595 Common Shares Issuable upon the Exercise of Warrants

This prospectus supplement amends and supplements the prospectus dated effective March 27, 2026, as supplemented or amended from time to time (the "Prospectus"), which forms a part of our Registration Statement on Form S-1 (Registration Statement No. 333-287599). This prospectus supplement is being filed to update and supplement the information included or incorporated by reference in the Prospectus with the information contained in our Current Report on Form 8-K, filed with the Securities and Exchange Commission on June 4, 2026 (the "Form 8-K"). Accordingly, we have attached the Form 8-K to this prospectus supplement.

This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not be delivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectus supplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in the Prospectus and this prospectus supplement, you should rely on the information in this prospectus supplement.

Our common shares and warrants, with an exercise price of $4.64 and expiration date of November 15, 2029 (the "Public Warrants"), are listed on The Nasdaq Capital Market ("Nasdaq") under the symbols "MDCX" and "MDCXW," respectively. On June 3, 2026, the last reported sales prices of the common shares and Public Warrants were $0.3576 and $0.50, respectively.

We are an "emerging growth company" under applicable Securities and Exchange Commission rules and are eligible for reduced public company disclosure requirements.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading "Risk Factors" beginning on page 7 of the Prospectus, and under similar headings in any amendment or supplements to the Prospectus.

None of the Securities and Exchange Commission, any state securities commission or the securities commission of any Canadian province or territory has approved or disapproved of the securities offered by this prospectus supplement or the Prospectus or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is June 4, 2026.

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): June 3, 2026

MEDICUS PHARMA LTD.
(Exact name of registrant as specified in its charter)

300 Conshohocken State Road, Suite 200
Conshohocken, Pennsylvania, United States 19428
(Address of principal executive offices) (ZIP Code)

Registrant’s telephone number, including area code: (610) 540-7515

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:

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 5.07. Submission of Matters to a Vote of Security Holders.

(a) Annual and Special Meeting. On June 3, 2026, Medicus Pharma Ltd. (the "Company") held its 2026 Annual General and Special Meeting of Shareholders (the "Meeting"). The matters voted upon at the Meeting and the final results of such voting are set forth below. A more complete description of each proposal is set forth in the Company's definitive proxy statement filed with the Securities and Exchange Commission on May 4, 2026.

(b) Matters Voted Upon; Voting Results. The following matters were submitted for a vote of the Company's shareholders.

Proposal 1. Shareholders ratified the appointment of KPMG LLP as the Company's independent registered public accounting firm for the Company's 2026 fiscal year and the authorization of the Company's board of directors (the "Board") to fix the auditors' remuneration and terms of engagement:

Proposal 2. Shareholders elected all nine of the directors nominated by the Board to serve for one-year terms, until our 2027 annual meeting of shareholders or until their successors are duly elected or appointed, unless they resign, are removed, or become disqualified in accordance with the Articles of Incorporation of the Company (the "Articles") or the Business Corporations Act (Ontario):

Proposal 3. Shareholders approved the special resolution authorizing the Board, in its discretion, to effect a consolidation of the Company's common shares, no par value (the "Common Shares") on the basis of a consolidation ratio to be determined by the Board, up to a maximum ratio of 50 pre-consolidation Common Shares for every one post-consolidation Common Share, if the Board determines such a consolidation is necessary or desirable, including, without limitation, for the purpose of meeting any applicable stock exchange or regulatory requirements. Shareholder approval of this Proposal 3 required the affirmative vote of at least two-thirds of the votes cast by the shareholders present at the Meeting in person or by proxy:

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.​

SIGNATURE

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.

Dated: June 4, 2026