EXECUTION VERSION ACASTI PHARMA INC. as the Corporation and COMPUTERSHARE TRUST COMPANY OF CANADA as the Warrant Agent WARRANT INDENTURE Providing for the Issue of Warrants Dated as of

TRUST COMPANY OF CANADA

as the Warrant Agent

Providing for the Issue of Warrants

Dated as of December 3, 2013

THIS WARRANT INDENTURE is dated as of December 3, 2013.

ACASTI PHARMA INC., a

corporation incorporated under the laws of the Province of Qu bec (the Corporation ),

COMPUTERSHARE TRUST COMPANY OF CANADA, a trust company existing under the laws of Canada and authorized to carry on business in all

provinces of Canada (the Warrant Agent ),

WHEREAS pursuant to the terms and conditions of an underwriting agreement dated

November 27, 2013 (the Underwriting Agreement ) the between the Corporation, Euro Pacific Canada Inc. and National Securities Corporation (collectively, the Underwriters ), the Corporation proposes to issue

and sell 16,000,000 units ( Units ) of the Corporation (the Offering ), each Unit comprised of one (1) Common Share (as defined herein) and one (1) Warrant (as defined herein);

AND WHEREAS for the purpose of the Offering, the Corporation is proposing to issue 16,000,000 Warrants and up to an additional 2,400,000 Warrants

(assuming the exercise of the over-allotment option (the Over-Allotment Option ) granted to the Underwriters) pursuant to this Indenture;

AND WHEREAS each Warrant shall, subject to adjustment, entitle the holder thereof to acquire one (1) Common Share upon payment of the Exercise

Price (as defined below) upon the terms and conditions herein set forth;

AND WHEREAS as of the date hereof the Corporation has an effective

Registration Statement (as defined below) under the U.S. Securities Act (as defined below);

AND WHEREAS all acts and deeds necessary have

been done and performed to make the Warrants, when created and issued as provided in this Indenture, legal, valid and binding upon the Corporation with the benefits and subject to the terms of this Indenture;

AND WHEREAS the foregoing recitals are made as representations and statements of fact by the Corporation and not by the Warrant Agent;

NOW THEREFORE, in consideration of the premises and mutual covenants hereinafter contained and other good

and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the Corporation hereby appoints the Warrant Agent as warrant agent to hold the rights, interests and benefits contained herein for and on behalf of those

persons who from time to time become the holders of Warrants issued pursuant to this Indenture and the parties hereto agree as follows:

In this Indenture, including the recitals and schedules hereto, and in all

indentures supplemental hereto:

Adjustment Period means the period from the Effective Date up to and including the Expiry Time;

Applicable Legislation means any statute of Canada or a province thereof, and the regulations under any such named or other statute,

relating to warrant indentures or to the rights, duties and obligations of warrant agents under warrant indentures, to the extent that such provisions are at the time in force and applicable to this Indenture;

Applicable Securities Laws means the applicable securities laws, regulations, rules, rulings and orders, including the applicable federal

and state securities laws and regulations of the United States, including the U.S. Securities Act, together with all related rules, policies, notices, blanket rulings, orders and all other regulatory instruments of the securities regulators in the

Provinces of Quebec, Ontario, Manitoba, Alberta and British Columbia, and the policies of the TSXV;

Auditors means a firm of chartered

accountants duly appointed as auditors of the Corporation;

Authenticated means (a) with respect to the issuance of a Warrant

Certificate, one which has been duly signed by the Corporation and authenticated by manual signature of an authorized officer of the Warrant Agent, (b) with respect to the issuance of an Uncertificated Warrant, one in respect of which the

Warrant Agent has completed all Internal Procedures such that the particulars of such Uncertificated Warrant as required by Section 2.7 are entered in the register of holders of Warrants, Authenticate ,

Authenticating and Authentication have the appropriate correlative meanings;

Participants means institutions that participate directly or indirectly in the Depository s book entry registration system for the Warrants;

Book Entry Only Warrants means Warrants that are to be held only by or on behalf of the Depository;

Business Day means any day other than Saturday, Sunday or a statutory or civic holiday, or any other day on which the banks are open for

business in Montreal, Qu bec or Toronto, Ontario;

CDS Global Warrants means Warrants representing all or a portion of the

aggregate number of Warrants issued in the name of the Depository represented by an Uncertificated Warrant, or if requested by the Depository or the Corporation, by a Warrant Certificate;

Certificated Warrant means a Warrant evidenced by a writing or writings substantially in the

form of Schedule A , attached hereto;

Common Shares means, subject to Article 4, fully paid and non-assessable

Class A shares of the Corporation as presently constituted;

Counsel means a barrister or solicitor or a firm of barristers and

solicitors retained by the Warrant Agent or retained by the Corporation and acceptable to the Warrant Agent, which may or may not be counsel for the Corporation;

Current Market Price of the Common Shares at any date means the weighted average of the trading price per Common Share for each day there

was a closing price for the five consecutive Trading Days ending on (and including) the third Trading Day immediately prior to such date on the TSXV or if on such date the Common Shares are not listed on the TSXV, on such stock exchange upon which

such Common Shares are listed and as selected by the directors, or, if such Common Shares are not listed on any stock exchange then on such over-the-counter market as may be selected for such purpose by the directors or, if not on any

over-the-counter-market, as determined by the directors of the Corporation;

Depository means CDS Clearing and Depository Services Inc.

or such other Person as is designated in writing by the Corporation to act as depository in respect of the Warrants;

any dividends paid by the Corporation;

Effective Date means the date of this Indenture;

Exchange Rate means the number of Common Shares subject to the right of purchase under each Warrant;

Exercise Date means, in relation to the Warrants, the Business Day on which such Warrant is validly exercised or deemed to be validly

exercised in accordance with Article 3 hereof;

Exercise Notice has the meaning set forth in Section 3.2(a);

Exercise Price at any time means the price at which a whole Common Share may be purchased by the exercise of a whole Warrant, which is

initially US$1.50 per Common Share, payable in U.S. funds, subject to adjustment in accordance with the provisions of Article 4;

Date means, December 3, 2018;

Expiry Time means 5:00 p.m. (Montreal time) on the Expiry Date;

Extraordinary Resolution has the meaning set forth in 7.11;

Issue Date means December 3, 2013;

Internal Procedures means in respect of the making of any one or more entries to, changes in or deletions of any one or more entries in the

register at any time (including without limitation, original issuance or registration of transfer of ownership) the minimum number of the Warrant Agent s internal procedures customary at such time for the entry, change or deletion made to be

complete under the operating procedures followed at the time by the Warrant Agent;

NASDAQ means The Nasdaq Stock Market;

Over-Allotment Option has the meaning set forth on the first page of this Warrant Indenture;

person means an individual, body corporate, partnership, trust, warrant agent, executor, administrator, legal representative or any

unincorporated organization;

register means the one set of records and accounts maintained by the Warrant Agent pursuant to

Registered Warrantholders means the persons who are registered owners of Warrants as such names appear on the

register, and for greater certainty, shall include the Depository as well as the holders of Uncertificated Warrants appearing on the register of the Warrant Agent;

Registration Statement means a registration statement filed with the SEC under the U.S. Securities Act registering the Common Shares

issuable upon the exercise of the Warrants;

SEC means the United States Securities and Exchange Commission;

Shareholders means the holders of Common Shares;

Tax Act means the Income Tax Act (Canada) and the regulations thereunder;

this Warrant Indenture , this Indenture , this Agreement , hereto

herein , hereby , hereof and similar expressions mean and refer to this indenture and any indenture, deed or instrument supplemental hereto; and the expressions Article ,

Section , subsection and paragraph followed by a number, letter or both mean and refer to the specified article, section, subsection or paragraph of this indenture;

Trading Day means, with respect to a stock exchange, a day on which such exchange is open for the transaction of business, and with respect

to an over-the-counter market, means a day on which the TSXV or Toronto Stock Exchange is open for the transaction of business;

Instruction means a written order signed by the holder or the Depository, entitled to request that one or more actions be taken, or such other form as may be reasonably acceptable to the Warrant Agent, requesting one or more such actions

to be taken in respect of an Uncertificated Warrant;

TSXV means the TSX Venture Exchange;

Uncertificated Warrant means any Warrant which is not a Certificated Warrant;

United States means the United States of America, its territories and possessions, any state of the United States, and the District of

U.S. Person has the meaning given to such term in Regulation S under the U.S. Securities Act;

U.S. Securities Act means the United States Securities Act of 1933, as amended;

Warrants means the Common Share purchase warrants created by and authorized by and issuable under this Indenture, to be issued and