Exhibit 4.13

AMENDMENT TO

DEVELOPMENT AND SUPPLY AGREEMENT

BETWEEN HOSPIRA WORLDWIDE, INC.

and

THERATECHNOLOGIES
INC.

This Amendment to the Development and Supply Agreement (Amendment) is made and
effective as of October 17, 2013 (Amendment Effective Date), by and between Hospira Worldwide, Inc. (Hospira), and Theratechnologies Inc. (Theratechnologies),
each herein referred to individually as a Party and collectively as the Parties. Capitalized terms used in this Amendment that are not otherwise defined herein shall have the meanings ascribed to such terms in the Kit Pack
Agreement (as defined herein). References to numbered sections and exhibits cited herein refer to specific sections of, and exhibits to the Kit Pack Agreement, as amended.

RECITALS

WHEREAS, Hospira and Theratechnologies are Parties to that certain Development and Supply Agreement with an effective
date of the 24th day of December, 2009 (Kit Pack Agreement); and

WHEREAS, the Parties now desire to amend the Kit Pack Agreement under the terms and conditions set forth below.

NOW, THEREFORE, in consideration of the mutual covenants and Kit Pack Agreements set forth in this Amendment,
and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties agree that the Kit Pack Agreement is amended as follows:



|1) | Section 4.8. The following sentence is added to the end of existing Section 4.8:
|-- | --------------------------------------------------------------------------------

For the avoidance of doubt, Hospiras option to increase the Kit Product price shall be effective for Kit Product
deliveries up to and including January 1, 2015 and until the expiry of this Kit Pack Agreement.



|2) | Section 9.1. Section 9.1 is hereby amended by replacing the text in its entirety with the following provisions:
|-- | ---------------------------------------------------------------------------------------------------------------

9.1 Term. This Kit Pack Agreement shall commence on the Effective Date and, unless
earlier terminated as provided below, shall expire automatically on March 25, 2015. The Parties may, but shall not be obligated to, extend the term of the Kit Pack Agreement for such periods of time and upon other terms and conditions as they
shall mutually agree.



|3) | Section 9.5. The language in Section 9.5 is hereby deleted in its entirety and replaced with the following:
|-- | -----------------------------------------------------------------------------------------------------------

Each party shall have the right to terminate the Agreement prior to the Term by giving the other
party six (6) months prior written notice.



---

|4) | Except as expressly amended herein, all other terms and conditions of the Kit Pack Agreement shall remain in full force and effect, and enforceable
in accordance with its terms. The terms and conditions of this Amendment are hereby incorporated into and made a part of the Kit Pack Agreement.
|-- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|5) | This Amendment may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute
one instrument. The Parties may sign and deliver this Amendment by facsimile or sent by electronic mail in portable document format (PDF) and a reproduction of this Amendment made by facsimile or PDF will have the same effect as a signed and
delivered original version.
|-- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

IN WITNESS WHEREOF, the Parties have each caused their duly
authorized representatives to execute this Amendment by signing below as of the above-referenced Amendment Effective Date.



|                                                                                       |  |                      |  |                                              |  |                                                   |  |                           
|-------------------------------------------------------------------------------------- |  | -------------------- |  | -------------------------------------------- |  | ------------------------------------------------- |  | --------------------------
|By:                                                                                    |  | (signed) Kevin Orfan |  |                                              |  | By:                                               |  | (signed) Luc Tanguay      
|                                                                                       |  | (Signature)          |  |                                              |  |                                                   |  | (Signature)               
|                                                                                       |  |                     
|Name: Kevin Orfan                                                                      |  |                      |  | Name: Luc Tanguay                           
|                                                                                       |  |                     
|Title: Director, Business Development
One 2 One Global Contract Manufacturing Services |  |                      |  | Title: President and Chief Executive Officer
|                                                                                       |  |                      |  |                                             
|                                                                                       |  |                      |  |                                              |  | By:                                               |  | (signed) Pierre Perazzelli
|                                                                                       |  |                      |  |                                              |  |                                                   |  | (Signature)               
|                                                                                       |  |                      | 
|                                                                                       |  |                      |  |                                              |  | Name: Pierre Perazzelli                          
|                                                                                       |  |                      | 
|                                                                                       |  |                      |  |                                              |  | Title: Vice President, Pharmaceutical Development



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|Hospira Worldwide, Inc. /Theratechnologies Kit Pack Amendment |  | Page 2 of 2