Filed Pursuant to Rule 424(b)(3)

Registration No. 333-287599

PROSPECTUS SUPPLEMENT NO. 8

(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 Reports on Form 8-K, filed with the Securities and Exchange Commission on September 11, 2026 and September 14, 2026 (together, the "Form 8-Ks"). Accordingly, we have attached the Form 8-Ks 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 September 11, 2026, the last reported sales prices of the common shares and Public Warrants were $0.1626 and $0.31, 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 September 14, 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): September 11, 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 1.02. Termination of a Material Definitive Agreement.

On September 11, 2026, Medicus Pharma Ltd. (the "Company") and YA II PN, LTD. ("Yorkville") mutually agreed to terminate the Standby Equity Purchase Agreement, dated as of February 10, 2025, between the Company and Yorkville (the "SEPA"), effective as of such date. Pursuant to the SEPA, the Company had the right to issue and sell to Yorkville up to $15.0 million of its common shares, no par value ("Common Shares"). At the time of the termination, there were no outstanding borrowings, advance notices or Common Shares to be issued under the SEPA. In addition, there are no fees due by the Company or Yorkville in connection with the termination of the SEPA. As previously disclosed in the Current Report on Form 8-K filed by the Company on December 30, 2025, Yorkville Securities, LLC, an affiliate of Yorkville, remains a sales agent under the Company's Equity Distribution Agreement dated December 29, 2025 (as amended).

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

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.

Dated: September 14, 2026