[424B3] Medicus Pharma Ltd. Prospectus Filed Pursuant to Rule 424(b)(3)

Rhea-AI Filing Summary

Medicus Pharma Ltd. filed a prospectus supplement updating its S-1 to cover 1,115,500 common shares issuable upon the exercise of warrants. The supplement incorporates a new Form 8-K.

The company also reported under the SEPA with Yorkville that it sold 1,088,048 common shares across multiple dates for approximately $2,526,364 in aggregate consideration, and used part of the net proceeds to prepay a portion of a debenture with Yorkville. The common shares and public warrants trade on Nasdaq as MDCX and MDCXW; on October 16, 2025, last reported prices were $2.41 and $0.90, respectively. The public warrants have a $4.64 exercise price and expire on November 15, 2029.

Insights

Capital Markets Analyst

Administrative supplement and SEPA draws; modest balance sheet actions.

Medicus Pharma updated its registration with a supplement listing 1,115,500 shares issuable upon warrant exercise. This is an administrative step that keeps disclosure current and does not itself change terms.

Separately, under its SEPA, the company sold 1,088,048 shares for approximately $2,526,364. The filing states a portion of the net proceeds was used to prepay a debenture with Yorkville, indicating a use of funds toward liabilities.

Future activity under the SEPA may occur subject to its conditions. Actual investor impact depends on any further draws and warrant exercises disclosed in subsequent filings.

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-279771

PROSPECTUS SUPPLEMENT NO. 17

(to prospectus dated April 10, 2025)

Medicus Pharma Ltd.

1,115,500 Common Shares Issuable upon the Exercise of Warrants

This prospectus supplement amends and supplements the prospectus dated effective April 10, 2025, 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. 333-279771). 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 October 17, 2025 (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 October 16, 2025, the last reported sales prices of the common shares and Public Warrants were $2.41 and $0.90, 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 10 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 October 17, 2025.

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): October 16, 2025

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

Ontario	001-42408	98-1778211
(State or other jurisdiction	(Commission	(IRS Employer
of incorporation)	File Number)	Identification No.)

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:

Title of each class		Trading Symbols		Name of each exchange on which registered
Common shares, no par value		MDCX		NASDAQ Capital Market
Warrants, each exercisable for one common share at an exercise price of $4.64 per share		MDCXW		NASDAQ Capital Market

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 3.02. Unregistered Sales of Equity Securities.

Pursuant to the previously disclosed Standby Equity Purchase Agreement (the "SEPA"), dated February 10, 2025, between Medicus Pharma Ltd. (the "Company") and YA II PN, Ltd. ("Yorkville"), the Company completed sales of its common shares (the "Common Shares") to Yorkville (collectively, the "SEPA Advances") as disclosed in the table below:

Date of Sale	Number of Common Shares	Price per share	Approximate Aggregate Consideration
September 8, 2025	100,000	$1.7961	$179,610
September 23, 2025	350,000	$2.4245	$848,575
September 26, 2025	100,000	$2.7698	$276,980
September 26, 2025	53,018	$2.4250	$128,569
October 2, 2025	250,000	$2.1884	$547,100
October 8, 2025	125,000	$2.3542	$294,275
October 16, 2025	41,667	$2.2901	$95,422
October 16, 2025	68,363	$2.2795	$155,833
Total	1,088,048		$2,526,364

The Company may cause Yorkville to purchase additional Common Shares under the SEPA from time to time, subject to the satisfaction or waiver of the conditions and limitations set forth in the SEPA. The Company has used part of the net proceeds from the SEPA Advances to prepay a portion of the debenture the Company has outstanding with Yorkville, as described in that certain Current Report on Form 8-K dated September 18, 2025. The Common Shares were issued and sold to Yorkville in reliance upon the exemption from the registration requirements of the Securities Act of 1933, as amended (the "Securities Act"), afforded by Section 4(a)(2) of the Securities Act. The Company is relying on this exemption from registration based in part on representations made by Yorkville in the SEPA. Yorkville may resell the Common Shares it has purchased from the Company under the SEPA from time to time pursuant to an effective registration statement which has been filed by the Company in accordance with its requirements under the SEPA for such purposes

This report shall not constitute an offer to sell or a solicitation of an offer to buy nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

​

Exhibit No.		Description
104	​	Cover Page Interactive Data File (embedded within the inline XBRL document).

Forward-Looking Statements

Certain information in this report constitutes "forward-looking information" under applicable securities laws. "Forward-looking information" is defined as disclosure regarding possible events, conditions or financial performance that is based on assumptions about future economic conditions and courses of action and includes, without limitation, statements regarding future sales of Common Shares under the SEPA to Yorkville. Forward-looking statements are often but not always, identified by the use of such terms as "may", "on track", "aim", "might", "will", "will likely result", "would", "should", "estimate", "plan", "project", "forecast", "intend", "expect", "anticipate", "believe", "seek", "continue", "target" or the negative and/or inverse of such terms or other similar expressions. These statements involve known and unknown risks, uncertainties and other factors, which may cause actual results, performance or achievements to differ materially from those expressed or implied by such statements, including those risk factors described in the Company's public filings on EDGAR and on SEDAR+, which may impact, among other things, the trading price and liquidity of the Common Shares. Forward-looking statements contained in this report are expressly qualified by this cautionary statement and reflect our expectations as of the date hereof and thus are subject to change thereafter. The Company disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

Readers are cautioned that the foregoing list is not exhaustive, and readers are encouraged to review the Company's annual report on Form 10-K on the Company's profile on EDGAR at www.sec.gov and on SEDAR+ at www.sedarplus.ca and the Company’s other public filings on EDGAR and on SEDAR+. Readers are further cautioned not to place undue reliance on forward-looking statements as there can be no assurance that the plans, intentions or expectations upon which they are placed will occur. Such information, although considered reasonable by management at the time of preparation, may prove to be incorrect and actual results may differ materially from those anticipated.

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.

​

MEDICUS PHARMA LTD.
By:	/s/ Raza Bokhari
Name:	Dr. Raza Bokhari
Title:	Executive Chairman and Chief Executive Officer

​

Dated: October 17, 2025​

FAQ

What did MDCX register in this prospectus supplement?

It covers 1,115,500 common shares issuable upon the exercise of warrants and updates the prospectus with a new Form 8-K.

How much did Medicus Pharma raise under the SEPA with Yorkville?

It sold 1,088,048 common shares for approximately $2,526,364 in aggregate consideration.

How were part of the SEPA proceeds used by MDCX?

The company used part of the net proceeds to prepay a portion of a debenture outstanding with Yorkville.

What are the terms of MDCX’s public warrants (MDCXW)?

Public warrants have an exercise price of $4.64 and an expiration date of November 15, 2029.

What were the last reported prices for MDCX and MDCXW on Oct 16, 2025?

The common shares were $2.41 and the public warrants were $0.90.

Is Medicus Pharma an emerging growth company?

Yes. The company states it is an emerging growth company and eligible for reduced disclosure requirements.

Can Yorkville resell the SEPA shares?

Yes. Yorkville may resell the purchased shares pursuant to an effective registration statement filed by the company.