UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

under the Securities Exchange Act of 1934

December 16, 2021

Commission File Number 001-35203

THERATECHNOLOGIES INC.

(Translation of registrant’s name into English)

2015 Peel Street, Suite 1100

Montréal, Québec, Canada

H3A 1T8

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F  ☐            Form 40-F  ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Yes  ☐            No  ☒

Note: Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Yes  ☐            No  ☒

Note: Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submitted to furnish a report or other document that the registrant foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant’s “home country”), or under the rules of the home country exchange on which the registrant’s securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant’s security holders, and, if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR.

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes  ☐            No  ☒

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82-                    .

Exhibit 99.1 to this Form 6-K is hereby filed and incorporated by reference in the registrant’s Registration Statement on Form F-10 (File No. 333-261289).

THERATECHNOLOGIES INC.

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, thereunto duly authorized.

Date: December 16, 2021

Exhibit 99.1

Theratechnologies Inc.

2015 Peel Street, Suite 1100

Montreal, Québec H3A 1T8

Canada

December 15, 2021

Cantor Fitzgerald & Co.

499 Park Avenue

New York, NY 10022

RE: Theratechnologies Inc. Common Shares Controlled Equity Offering Sales Agreement

Ladies and Gentlemen:

Reference is made to that certain Sales Agreement (the “Sales Agreement”), dated July 23, 2021, by and between Theratechnologies Inc., a corporation formed under the Companies Act (Québec) and continued under the Business Corporations Act (Québec) (the “Company”), and Cantor Fitzgerald & Co (the “Agent”). All terms used herein but not otherwise defined have the definitions provided in the Sales Agreement.

In consideration for each party’s agreement to the terms of this Letter Agreement, and pursuant to the terms of Section 12(d) of the Sales Agreement, the Company and Agent acknowledge and agree that (i) the maximum amount of gross proceeds of Placement Shares to be sold under the Sales Agreement has not been reached, (ii) the Company has filed or will file with the AMF a new Canadian preliminary short form base shelf prospectus, together with a new prospectus supplement relating to the offering of Placement Shares, (iii) the Company has filed or will file with the Commission a new registration statement on Form F-10 and the Canadian prospectus supplement relating to the offering of Placement Shares, in the case of clauses (ii) and (iii) both with the effect of renewing such documents and (iv) the Sales Agreement shall continue and remain in effect, and will govern the offering of Placement Shares.

Except as specifically provided for in this Letter Agreement, the Sales Agreement shall remain unmodified and in full force and effect. This Letter Agreement shall be governed in all respects by the laws of the State of New York. This Letter Agreement may be executed in counterparts each of which will be deemed to be an original and all of which taken together evidence the same Letter Agreement.

[Signature page follows]

Yours faithfully,

Acknowledged and agreed as of the date first written above:

[Signature Page to Letter Agreement]