Exhibit 3.1

EXHIBIT A

CERTIFICATE OF INCORPORATION

OF

PEPLIN, INC.

I.

     The name of this corporation is Peplin, Inc.

II.

     The address of the registered office of the corporation in the State of Delaware is 2711 Centerville Road, Suite 400, City of Wilmington, County of New Castle. The name of the registered agent of the corporation in the State of Delaware at such address is Corporation Service Company.

III.

     The purpose of this corporation is to engage in any lawful act or activity for which a corporation may be organized under the Delaware General Corporation Law (“DGCL”).

IV.

     The corporation is authorized to issue only one class of stock, to be designated Common Stock. The total number of shares of Common Stock which the corporation is presently authorized to issue is One Hundred (100) shares, each having a par value of one-tenth of one cent ($ 0.001).

V.

     A. The management of the business and the conduct of the affairs of the corporation shall be vested in its Board of Directors. The number of directors which shall constitute the whole Board of Directors shall be fixed by the Board of Directors in the manner provided in the Bylaws.

     B. Election of Directors

          1. Directors shall be elected at each annual meeting of stockholders to hold office until the next annual meeting. Each director shall hold office either until the expiration of the term for which elected and appointed and until a successor has been elected and qualified, or until such director’s death, resignation or removal. No decrease in the number of directors constituting the Board of Directors shall shorten the term of any incumbent director.

          2. No person entitled to vote at an election for directors may cumulate votes to which such person is entitled, unless, at the time of such election, the corporation is subject to Section 2115(b) of the California General Corporation Law (“CGCL”). During such time or times that the corporation is subject to Section 2115(b) of the CGCL, every stockholder entitled to vote at an election for directors may cumulate such stockholder’s votes and give one candidate a number of votes equal to the number of directors to be elected multiplied by the number of votes to which such stockholder’s shares are otherwise entitled, or distribute the stockholder’s votes on the same principle among as many candidates as such stockholder thinks fit. No stockholder, however, shall be entitled to so cumulate such stockholder’s votes unless (a) the names of such candidate or candidates have been placed in nomination prior to the voting and (b) the stockholder has given notice at the meeting, prior to the voting, of such stockholder’s intention to cumulate such stockholder’s votes. If any stockholder has given proper notice to cumulate votes, all stockholders may cumulate their votes for any candidates who have been properly placed in nomination. Under cumulative voting, the candidates receiving the highest number of votes, up to the number of directors to be elected, are elected.

     C. Removal

          1. During such time or times that the corporation is subject to Section 21l5(b) of the CGCL, the Board of Directors or any individual director may be removed from office at any time without cause by the affirmative vote of the holders of at least a majority of the outstanding shares entitled to vote on such removal; provided, however, that unless the entire Board is removed, no individual director may be removed when the votes cast against such director’s removal, or not consenting in writing to such removal, would be sufficient to elect that director if voted cumulatively at an election which the same total number of votes were cast (or, if such action is taken by written consent, all shares entitled to vote were voted) and the entire number of directors authorized at the time of such director’s most recent election were then being elected.

          2. At any time or times that the corporation is not subject to Section 2115(b) of the CGCL and subject to any limitations imposed by law, Section C.l above shall not apply and the Board of Directors or any director may be removed from office at any time (a) with cause by the affirmative vote of the holders of a majority of the voting power of all then-outstanding shares of capital stock of the corporation entitled to vote at an election of directors or (b) without cause by the affirmative vote of the holders of a majority of the voting power of all then-outstanding shares of capital stock of the corporation, entitled to vote generally at an election of directors.

     D. The Board of Directors is expressly empowered to adopt, amend or repeal the Bylaws of the corporation. The stockholders shall also have power to adopt, amend or repeal the Bylaws of the corporation; provided, however, that, in addition to any vote of the holders of any class or series of stock of the corporation required by law or by this Certificate of Incorporation, the affirmative vote of the holders of at least a majority of the voting power of all the then-outstanding shares of the capital stock of the corporation entitled to vote generally in the election

of directors, voting together as a single class, shall be required to adopt, amend or repeal any provision of the Bylaws of the corporation.

VI.

     A. The liability of the directors for monetary damages shall be eliminated to the fullest extent under applicable law. If the DGCL is amended to authorize corporate action further eliminating or limiting the personal liability of directors, then the liability of a director of the corporation shall be eliminated or limited to the fullest extent permitted by the DGCL, as so amended.

     B. This corporation is authorized to provide indemnification of agents (as defined in Section 317 of the CGCL) for breach of duty to the corporation and its stockholders through bylaw provisions through agreements with the agents, or through stockholder resolutions, or otherwise, in excess of the indemnification otherwise permitted by Section 317 of the CGCL, subject, at any time or times that the corporation is subject to Section 2115(b) of the CGCL, to the limits on such excess indemnification set forth in Section 204 of the CGCL.

     C. Any repeal or modification of this Article VI shall be prospective and shall not affect the rights under this Article VI in effect at the time of the alleged occurrence of any act or omission to act giving rise to liability or indemnification.

VII.

     The corporation reserves the right to amend, alter, change or repeal any provision contained in this Certificate of Incorporation, in the manner now or hereafter prescribed by statute, and all rights conferred upon the stockholders herein are granted subject to this reservation.