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                                                                     EXHIBIT 3.4

                          AMENDED AND RESTATED BYLAWS
                                      OF
                          ESPERION THERAPEUTICS, INC.

             Incorporated under the Laws of the State of Delaware

                                   ARTICLE I

                             OFFICERS AND RECORDS

SECTION 1.01  Delaware Office.  The Corporation shall maintain a registered
              ---------------
office and registered agent within the State of Delaware, which may be changed
by the Board of Directors from time to time. The address of the Corporation's
principal office in Delaware is: 1013 Centre Road, Wilmington, New Castle
County. The name of the registered agent is: Corporation Service Company, Inc.

SECTION 1.02  Other Offices.  The Corporation may have such other offices,
              -------------
either within or without the State of Delaware, as the Board of Directors may
designate or as the business of the Corporation may from time to time require.

SECTION 1.03  Books and Records.  The books and records of the Corporation may
              -----------------
be kept outside the State of Delaware at such place or places as may from time
to time be designated by the Board of Directors.

                                  ARTICLE II

                                 STOCKHOLDERS

SECTION 2.01  Annual Meeting.  The annual meeting of the stockholders of the
              --------------
Corporation shall be held on such date and at such place and time as may be
fixed by resolution of the Board of Directors.

SECTION 2.02  Special Meeting.  Subject to the rights of the holders of any
              ---------------
series of stock having a preference over the Common Stock of the Corporation as
to dividends or upon liquidation ("Preferred Stock") with respect to such series
of Preferred Stock, special meetings of the stockholders may be called only by
the Chairman of the Board or by the Board of Directors pursuant to a resolution
adopted by a majority of the total number of directors which the Corporation
would have if there were no vacancies (the "Whole Board").

SECTION 2.03  Place of Meeting.  The Board of Directors or the Chairman of the
              ----------------
Board, as the case may be, may designate the place of meeting for any annual
meeting or for any special meeting of the stockholders called by the Board of
Directors or the
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Chairman of the Board. If no designation is so made, the place of meeting shall
be the principal office of the Corporation.

SECTION 2.04  Notice of Meeting.  Written or printed notice, stating the place,
              -----------------
day and hour of the meeting and the purpose or purposes for which the meeting is
called, shall be delivered by the Corporation not less than ten (10) days nor
more than sixty (60) days before the date of the meeting, either personally or
by mail, to each stockholder of record entitled to vote at such meeting.  If
mailed, such notice shall be deemed to be delivered when deposited in the United
States mail with postage thereon prepaid, addressed to the stockholder at his
address as it appears on the stock transfer books of the Corporation.  Such
further notice shall be given as may be required by law.  Only such business
shall be conducted at a special meeting of stockholders as shall have been
brought before the meeting pursuant to the Corporation's notice of meeting.
Meetings may be held without notice if all stockholders entitled to vote are
present, or if notice is waived by those not present in accordance with Section
6.04 of these Bylaws.  Any previously scheduled meeting of the stockholders may
be postponed, and (unless the Certificate of Incorporation otherwise provides)
any special meeting of the stockholders may be cancelled, by resolution of the
Board of Directors upon public notice given prior to the date previously
scheduled for such meeting of stockholders.

SECTION 2.05  Quorum and Adjournment.  Except as otherwise provided by law or by
              ----------------------
the Certificate of Incorporation, the holders of a majority of the outstanding
shares of the Corporation entitled to vote generally in the election of
directors (the "Voting Stock"), represented in person or by proxy, shall
constitute a quorum at a meeting of stockholders, except that when specified
business is to be voted on by a class or series of stock voting as a class, the
holders of a majority of the shares of such class or series shall constitute a
quorum of such class or series for the transaction of such business.  The
Chairman of the meeting or a majority of the shares so represented may adjourn
the meeting from time to time, whether or not there is such a quorum.  No notice
of the time and place of adjourned meetings need be given except as required by
law.  The stockholders present at a duly called meeting at which a quorum is
present may continue to transact business until adjournment, notwithstanding the
withdrawal of enough stockholders to leave less than a quorum.

SECTION 2.06  Proxies.  At all meetings of stockholders, a stockholder may vote
              -------
by proxy executed in writing (or in such manner prescribed by the General
Corporation Law of the State of Delaware) by the stockholder, or by his duly
authorized attorney in fact.

SECTION 2.07  Notice of Stockholder Business and Nominations.
              ----------------------------------------------

         (A)  Annual Meetings of Stockholders.

              (1)  Nominations of persons for election to the Board of Directors
of the Corporation and the proposal of business to be considered by the
stockholders may

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be made at an annual meeting of stockholders (a) pursuant to the Corporation's
notice of meeting, (b) by or at the direction of the Board of Directors or (c)
by any stockholder of the Corporation who was a stockholder of record at the
time of giving of notice provided for in this Bylaw, who is entitled to vote at
the meeting and who complies with the notice procedures set forth in this Bylaw.

              (2)  For nominations or other business to be properly brought
before an annual meeting by a stockholder pursuant to clause (c) of paragraph
(A) (1) of this Bylaw, the stockholder must have given timely notice thereof in
writing to the Secretary of the Corporation and such other business must
otherwise be a proper matter for stockholder action. To be timely, a
stockholder's notice shall be delivered to the Secretary at the principal
executive offices of the Corporation not later than the close of business on the
day prior to the first anniversary of the preceding year's annual meeting;
provided, however, that in the event that the date of the annual meeting is more
than 30 days before or more than 60 days after such anniversary date, notice by
the stockholder to be timely must be so delivered not earlier than the close of
business on the 90th day prior to such annual meeting and not later than the
close of business on the later of the 60th day prior to such annual meeting or
the 10th day following the day on which public announcement of the date of such
meeting is first made by the Corporation. In no event shall the public
announcement of an adjournment of an annual meeting commence a new time period
for the giving of a stockholder's notice as described above. Such stockholder's
notice shall set forth (a) as to each person whom the stockholder proposes to
nominate for election or reelection as a director all information relating to
such person that is required to be disclosed in solicitations of proxies for
election of directors in an election contest, or is otherwise required, in each
case pursuant to Regulation 14A under the Securities Exchange Act of 1934, as
amended (the "Exchange Act") and Rule 14a-11 thereunder (including such person's
written consent to being named in the proxy statement as a nominee and to
serving as a director if elected); (b) as to any other business that the
stockholder proposes to bring before the meeting, a brief description of the
business desired to be brought before the meeting, the reasons for conducting
such business at the meeting and any material interest in such business of such
stockholder and the beneficial owner, if any, on whose behalf the proposal is
made; and (c) as to the stockholder giving the notice and the beneficial owner,
if any, on whose behalf the nomination or proposal is made (i) the name and
address of such stockholder, as they appear on the Corporation's books, and of
such beneficial owner and (ii) the class and number of shares of the Corporation
which are owned beneficially and of record by such stockholder and such
beneficial owner.

              (3)  Notwithstanding anything in the second sentence of paragraph
(A) (2) of this Bylaw to the contrary, in the event that the number of directors
to be elected to the Board of Directors of the Corporation is increased and
there is no public announcement by the Corporation naming all of the nominees
for director or specifying the size of the increased Board of Directors at least
70 days prior to the first anniversary of the preceding year's annual meeting, a
stockholder's notice required by this Bylaw shall also be considered timely, but
only with respect to nominees for any new positions created by such increase, if
it shall be delivered to the Secretary at the principal executive

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offices of the Corporation not later than the close of business on the 10th day
following the day on which such public announcement is first made by the
Corporation.

          (B)  Special Meetings of Stockholders. Only such business shall be
               --------------------------------
conducted at a special meeting of stockholders as shall have been brought before
the meeting pursuant to the Corporation's notice of meeting. Nominations of
persons for election to the Board of Directors may be made at a special meeting
of stockholders at which directors are to be elected pursuant to the
Corporation's notice of meeting (a) by or at the direction of the Board of
Directors or (b) provided that the Board of Directors has determined that
directors shall be elected at such meeting, by any stockholder of the
Corporation who is a stockholder of record at the time of giving of notice
provided for in this Bylaw, who shall be entitled to vote at the meeting and who
complies with the notice procedures set forth in this Bylaw. In the event the
Corporation calls a special meeting of stockholders for the purpose of electing
one or more directors to the Board of Directors, any such stockholder may
nominate a person or persons (as the case may be), for election to such
position(s) as specified in the Corporation's notice of meeting, if the
stockholder's notice required by paragraph (A) (2) of this Bylaw shall be
delivered to the Secretary at the principal executive offices of the Corporation
not earlier than the close of business on the 90th day prior to such special
meeting and not later than the close of business on the later of the 60th day
prior to such special meeting or the 10th day following the day on which public
announcement is first made of the date of the special meeting and of the
nominees proposed by the Board of Directors to be elected at such meeting. In no
event shall the public announcement of an adjournment of a special meeting
commence a new time period for the giving of a stockholder's notice as described
above.

          (C)  General.

               (1)  Only such persons who are nominated in accordance with the
procedures set forth in this Bylaw shall be eligible to serve as directors and
only such business shall be conducted at a meeting of stockholders as shall have
been brought before the meeting in accordance with the procedures set forth in
this Bylaw. Except as otherwise provided by law, the Certificate of
Incorporation or these Bylaws, the Chairman of the meeting shall have the power
and duty to determine whether a nomination or any business proposed to be
brought before the meeting was made or proposed, as the case may be, in
accordance with the procedures set forth in this Bylaw and, if any proposed
nomination or business is not in compliance with this Bylaw, to declare that
such defective proposal or nomination shall be disregarded.

               (2)  For purposes of this Bylaw, "public announcement" shall mean
disclosure in a press release reported by the Dow Jones News Service, Associated
Press or comparable national news service or in a document publicly filed by the
Corporation with the Securities and Exchange Commission pursuant to Section 13,
14 or 15(d) of the Exchange Act.

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               (3)  Notwithstanding the foregoing provisions of this Bylaw, a
stockholder shall also comply with all applicable requirements of the Exchange
Act and the rules and regulations thereunder with respect to the matters set
forth in this Bylaw. Nothing in this Bylaw shall be deemed to affect any rights
(i) of stockholders to request inclusion of proposals in the Corporation's proxy
statement pursuant to Rule 14a-8 under the Exchange Act or (ii) of the holders
of any series of Preferred Stock to elect directors under specified
circumstances.

SECTION 2.08   Procedure for Election of Directors; Required Vote.  Election of
               --------------------------------------------------
directors at all meetings of the stockholders at which directors are to be
elected shall be by ballot, and, subject to the rights of the holders of any
series of Preferred Stock to elect directors under specified circumstances, a
plurality of the votes cast thereat shall elect directors.  Except as otherwise
provided by law, the Certificate of Incorporation, or these Bylaws, in all
matters other than the election of directors, the affirmative vote of a majority
of the shares present in person or represented by proxy at the meeting and
entitled to vote on the matter shall be the act of the stockholders.

SECTION 2.09   Inspectors of Elections; Opening and Closing the Polls. The Board
               -----------------------------------------------------
of Directors by resolution shall appoint one or more inspectors, which inspector
or inspectors may include individuals who serve the Corporation in other
capacities, including, without limitation, as officers, employees, agents or
representatives, to act at the meetings of stockholders and make a written
report thereof.  One or more persons may be designated as alternate inspectors
to replace any inspector who fails to act.  If no inspector or alternate has
been appointed to act or is able to act at a meeting of stockholders, the
Chairman of the meeting shall appoint one or more inspectors to act at the
meeting.  Each inspector, before discharging his or her duties, shall take and
sign an oath faithfully to execute the duties of inspector with strict
impartiality and according to the best of his or her ability.  The inspectors
shall have the duties prescribed by law.

          The Chairman of the meeting shall fix and announce at the meeting the
date and time of the opening and the closing of the polls for each matter upon
which the stockholders will vote at a meeting.

SECTION 2.10   No Stockholder Action by Written Consent.  Subject to the rights
               ----------------------------------------
of the holders of any series of Preferred Stock with respect to such series of
Preferred Stock, any action required or permitted to be taken by the
stockholders of the Corporation must be effected at an annual or special meeting
of stockholders of the Corporation and may not be affected by any consent in
writing by such stockholders.

                                  ARTICLE III

                              BOARD OF DIRECTORS

SECTION 3.01   General Powers. The business and affairs of the Corporation shall
               --------------
be managed under the direction of the Board of Directors.  In addition to the
powers and

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authorities by these Bylaws expressly conferred upon them, the Board of
Directors may exercise all such powers of the Corporation and do all such lawful
acts and things as are not by statute or by the Certificate of Incorporation or
by these Bylaws required to be exercised or done by the stockholders.

SECTION 3.02   Number, Tenure and Qualifications.  Subject to the rights of the
               ---------------------------------
holders of any series of Preferred Stock to elect directors under specified
circumstances, the number of directors shall be fixed from time to time
exclusively pursuant to a resolution adopted by a majority of the Whole Board.
The Board of Directors shall be and is divided into three classes:  Class I,
Class II and Class III. Each class of directors shall be as nearly equal in
number as possible.  Each Director shall serve for a term ending on the date of
the third annual meeting following the annual meeting at which such Director was
elected; provided, that each initial Director in Class I shall serve for a term
ending on the date of the annual meeting in 2001; each initial Director in Class
II shall serve for a term ending on the date of the annual meeting in 2002; and
each initial Director in Class III shall serve for a term ending on the date of
the annual meeting in 2003; and provided further, that the term of each Director
shall be subject to the election and qualification of his successor and to his
earlier death, resignation or removal.

SECTION 3.03   Regular Meetings.  A regular meeting of the Board of Directors
               ----------------
shall be held without other notice than this Bylaw immediately after, and at the
same place as, the Annual Meeting of Stockholders.  The Board of Directors may,
by resolution, provide the time and place for the holding of additional regular
meetings without other notice than such resolution.

SECTION 3.04   Special Meetings.  Special meetings of the Board of Directors
               ----------------
shall be called at the request of the Chairman of the Board, the President or a
majority of the Board of Directors then in office.  The person or persons
authorized to call special meetings of the Board of Directors may fix the place
and time of the meetings.

SECTION 3.05   Notice. Notice of any special meeting of directors shall be given
               ------
to each director at his business or residence in writing by hand delivery,
first-class or overnight mail or courier service, telegram or facsimile
transmission, or orally by telephone.  If mailed by first-class mail, such
notice shall be deemed adequately delivered when deposited in the United States
mails so addressed, with postage thereon prepaid, at least five (5) days before
such meeting.  If by telegram, overnight mail or courier service, such notice
shall be deemed adequately delivered when the telegram is delivered to the
telegraph company or the notice is delivered to the overnight mail or courier
service company at least twenty-four (24) hours before such meeting.  If by
facsimile transmission, such notice shall be deemed adequately delivered when
the notice is transmitted at least twelve (12) hours before such meeting.  If by
telephone or by hand delivery, the notice shall be given at least twelve (12)
hours prior to the time set for the meeting.  Neither the business to be
transacted at, nor the purpose of, any regular or special meeting of the Board
of Directors need be specified in the notice of such meeting, except for
amendments to these Bylaws, as provided under Section 8.1.  A meeting may

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be held at any time without notice if all the directors are present or if those
not present waive notice of the meeting in accordance with Section 6.4 of these
Bylaws.

SECTION 3.06   Action by Consent of Board of Directors.  Any action required or
               ---------------------------------------
permitted to be taken at any meeting of the Board of Directors or of any
committee thereof may be taken without a meeting if all members of the Board or
committee, as the case may be, consent thereto in writing, and the writing or
writings are filed with the minutes of proceedings of the Board or committee.

SECTION 3.07   Conference Telephone Meetings. Members of the Board of Directors,
               -----------------------------
or any committee thereof, may participate in a meeting of the Board of Directors
or such committee by means of conference telephone or similar communications
equipment by means of which all persons participating in the meeting can hear
each other, and such participation in a meeting shall constitute presence in
person at such meeting.

SECTION 3.08   Quorum. Subject to Section 3.9, a whole number of directors equal
               ------
to at least a majority of the Whole Board shall constitute a quorum for the
transaction of business, but if at any meeting of the Board of Directors there
shall be less than a quorum present, a majority of the directors present may
adjourn the meeting from time to time without further notice.  The act of the
majority of the directors present at a meeting at which a quorum is present
shall be the act of the Board of Directors.  The directors present at a duly
organized meeting may continue to transact business until adjournment,
notwithstanding the withdrawal of enough directors to leave less than a quorum.

SECTION 3.09   Vacancies.  Subject to applicable law and the rights of the
               ---------
holders of any series of Preferred Stock with respect to such series of
Preferred Stock, and unless the Board of Directors otherwise determines,
vacancies resulting from death, resignation, retirement, disqualification,
removal from office or other cause, and newly created directorships resulting
from any increase in the authorized number of directors, may be filled only by
the affirmative vote of a majority of the remaining directors, though less than
a quorum of the Board of Directors, and directors so chosen shall hold office
for a term expiring at the annual meeting of stockholders at which the term of
office of the class to which they have been elected expires and until such
director's successor shall have been duly elected and qualified.  No decrease in
the number of authorized directors constituting the Whole Board shall shorten
the term of any incumbent director.

SECTION 3.10   Executive and Other Committees.  The Board of Directors may, by
               ------------------------------
resolution adopted by a majority of the Whole Board, designate an Executive
Committee to exercise, subject to applicable provisions of law, all the powers
of the Board in the management of the business and affairs of the Corporation
when the Board is not in session, including without limitation the power to
declare dividends, to authorize the issuance of the Corporation's capital stock
and to adopt a certificate of ownership and merger pursuant to Section 253 of
the General Corporation Law of the State of Delaware, and may, by resolution
similarly adopted, designate one or more other committees.  The

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Executive Committee and each such other committee shall consist of two or more
directors of the Corporation. The Board may designate one or more directors as
alternate members of any committee, who may replace any absent or disqualified
member at any meeting of the committee. Any such committee, other than the
Executive Committee (the powers of which are expressly provided for herein), may
to the extent permitted by law exercise such powers and shall have such
responsibilities as shall be specified in the designating resolution. In the
absence or disqualification of any member of such committee or committees, the
member or members thereof present at any meeting and not disqualified from
voting, whether or not constituting a quorum, may unanimously appoint another
member of the Board to act at the meeting in the place of any such absent or
disqualified member. Each committee shall keep written minutes of its
proceedings and shall report such proceedings to the Board when required.

     A majority of any committee may determine its action and fix the time and
place of its meetings, unless the Board shall otherwise provide. Notice of such
meetings shall be given to each member of the committee in the manner provided
for in Section 3.5 of these Bylaws. The Board shall have power at any time to
fill vacancies in, to change the membership of, or to dissolve any such
committee. Nothing herein shall be deemed to prevent the Board from appointing
one or more committees consisting in whole or in part of persons who are not
directors of the Corporation; provided, however, that no such committee shall
have or may exercise any authority of the Board.

SECTION 3.11   Removal.  Subject to the rights of the holders of any series of
               -------
Preferred Stock with respect to such series of Preferred Stock, any director, or
the entire Board of Directors, may be removed from office at any time, but only
for cause and only by the affirmative vote of the holders of at least 66 2/3
percent of the voting power of all of the then-outstanding shares of Voting
Stock, voting together as a single class.

SECTION 3.12   Records.  The Board of Directors shall cause to be kept a record
               -------
containing the minutes of the proceedings of the meetings of the Board and of
the stockholders, appropriate stock books and registers and such books of
records and accounts as may be necessary for the proper conduct of the business
of the Corporation.

                                  ARTICLE IV

                                   OFFICERS

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SECTION 4.01  Elected Officers.  The elected officers of the Corporation shall
              ----------------
be a Chairman of the Board of Directors, a Chief Executive Officer, a President,
a Secretary, and such other officers (including, without limitation, a Chief
Financial Officer) as the Board of Directors from time to time may deem proper.
The Chairman of the Board shall be chosen from among the directors. All officers
elected by the Board of Directors shall each have such powers and duties as
generally pertain to their respective offices, subject to the specific
provisions of this ARTICLE IV. Such officers shall also have such powers and
duties as from time to time may be conferred by the Board of Directors or by any
committee thereof. The Board or any committee thereof may from time to time
elect, or the Chairman of the Board or President may appoint, such other
officers (including one or more Assistant Vice Presidents, Assistant
Secretaries, Assistant Treasurers, and Assistant Controllers) and such agents,
as may be necessary or desirable for the conduct of the business of the
Corporation. Such other officers and agents shall have such duties and shall
hold their offices for such terms as shall be provided in these Bylaws or as may
be prescribed by the Board or such committee or by the Chairman of the Board or
President, as the case may be.

SECTION 4.02  Election and Term of Office.  The elected officers of the
              ---------------------------
Corporation shall be elected annually by the Board of Directors at the regular
meeting of the Board of Directors held after the annual meeting of the
stockholders.  If the election of officers shall not be held at such meeting,
such election shall be held as soon thereafter as convenient.  Each officer
shall hold office until his successor shall have been duly elected and shall
have qualified or until his death or until he shall resign, but any officer may
be removed from office at any time by the affirmative vote of a majority of the
Whole Board or, except in the case of an officer or agent elected by the Board,
by the Chairman of the Board or President.  Such removal shall be without
prejudice to the contractual rights, if any, of the person so removed.

SECTION 4.03  Chairman of the Board.  The Chairman of the Board shall preside at
              ---------------------
all meetings of the stockholders and of the Board of Directors.  The Chairman of
the Board shall be responsible for the general management of the affairs of the
Corporation and shall perform all duties incidental to his office which may be
required by law and all such other duties as are properly required of him by the
Board of Directors.  He shall make reports to the Board of Directors and the
stockholders, and shall see that all orders and resolutions of the Board of
Directors and of any committee thereof are carried into effect.  The Chairman of
the Board may also serve as President, if so elected by the Board.

SECTION 4.04  Chief Executive Officer.  The Chief Executive Officer shall be the
              -----------------------
head of the corporation and in the recess of the Board of Directors and the
executive committee shall have the general control and management of all the
business and affairs of the corporation.  He shall also exercise such further
powers and perform such other duties as may from time to time be conferred upon
or assigned by these Bylaws, the Board of Directors or the executive committee.
He shall make annual reports and submit the same to the Board of Directors and
also to the shareholders at their annual meeting, showing the condition and the
affairs of the corporation.  He shall from time to time

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make such recommendations to the Board of Directors, the executive committee and
any other committee as he thinks proper and shall bring before the Board of
Directors, the executive committee and any other committee such information as
may be required, relating to the business and property of the corporation.

SECTION 4.05  President.  The President shall act in a general executive
              ---------
capacity and shall assist the Chairman of the Board in the administration and
operation of the Corporation's business and general supervision of its policies
and affairs.  The President shall, in the absence of or because of the inability
to act of the Chairman of the Board, perform all duties of the Chairman of the
Board and preside at all meetings of stockholders and of the Board of Directors.

SECTION 4.06  Vice-Presidents.  Each Vice President shall have such powers and
              ---------------
shall perform such duties as shall be assigned to him by the Board of Directors.

SECTION 4.07  Secretary.  The  Secretary shall keep or cause to be kept in one
              ---------
or more books provided for that purpose, the minutes of all meetings of the
Board, the committees of the Board and the stockholders; he shall see that all
notices are duly given in accordance with the provisions of these Bylaws and as
required by law; he shall be custodian of the records and the seal of the
Corporation and affix and attest the seal to all stock certificates of the
Corporation (unless the seal of the Corporation on such certificates shall be a
facsimile, as hereinafter provided) and affix and attest the seal to all other
documents to be executed on behalf of the Corporation under its seal; and he
shall see that the books, reports, statements, certificates and other documents
and records required by law to be kept and filed are properly kept and filed;
and in general, he shall perform all the duties incident to the office of
Secretary and such other duties as from time to time may be assigned to him by
the Board, the Chairman of the Board or the President.

SECTION 4.08  Removal.  Any officer elected, or agent appointed, by the Board of
              -------
Directors may be removed by the affirmative vote of a majority of the Whole
Board whenever, in their judgment, the best interests of the Corporation would
be served thereby.  Any officer or agent appointed by the Chairman of the Board
or the President may be removed by him whenever, in his judgment, the best
interests of the Corporation would be served thereby.  No elected officer shall
have any contractual rights against the Corporation for compensation by virtue
of such election beyond the date of the election of his successor, his death,
his resignation or his removal, whichever event shall first occur, except as
otherwise provided in an employment contract or under an employee deferred
compensation plan.

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SECTION 4.09  Vacancies.  A newly created elected office and a vacancy in any
              ---------
elected office because of death, resignation, or removal may be filled by the
Board of Directors for the unexpired portion of the term at any meeting of the
Board of Directors.  Any vacancy in an office appointed by the Chairman of the
Board or the President because of death, resignation, or removal may be filled
by the Chairman of the Board or the President.

                                   ARTICLE V

                       STOCK CERTIFICATES AND TRANSFERS

SECTION 5.01  Stock Certificates and Transfers.  The interest of each
              --------------------------------
stockholder of the Corporation shall be evidenced by certificates for shares of
stock in such form as the appropriate officers of the Corporation may from time
to time prescribe.  The shares of the stock of the Corporation shall be
transferred on the books of the Corporation by the holder thereof in person or
by his attorney, upon surrender for cancellation of certificates for at least
the same number of shares, with an assignment and power of transfer endorsed
thereon or attached thereto, duly executed, with such proof of the authenticity
of the signature as the Corporation or its agents may reasonably require.

     The certificates of stock shall be signed, countersigned and registered in
such manner as the Board of Directors may by resolution prescribe, which
resolution may permit all or any of the signatures on such certificates to be in
facsimile. In case any officer, transfer agent or registrar who has signed or
whose facsimile signature has been placed upon a certificate has ceased to be
such officer, transfer agent or registrar before such certificate is issued, it
may be issued by the Corporation with the same effect as if he were such
officer, transfer agent or registrar at the date of issue.

SECTION 5.02  Lost, Stolen or Destroyed Certificates.  No certificate for shares
              --------------------------------------
of stock in the Corporation shall be issued in place of any certificate alleged
to have been lost, destroyed or stolen, except on production of such evidence of
such loss, destruction or theft and on delivery to the Corporation of a bond of
indemnity in such amount, upon such terms and secured by such surety, as the
Board of Directors or any financial officer may in its or his discretion
require.

                                  ARTICLE VI

                           MISCELLANEOUS PROVISIONS

SECTION 6.01  Fiscal Year.  The fiscal year of the Corporation shall begin on
              -----------
the first day of January and end on the thirty-first day of December of each
year.

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SECTION 6.02  Dividends.  The Board of Directors may from time to time declare,
              ---------
and the Corporation may pay, dividends on its outstanding shares in the manner
and upon the terms and conditions provided by law and the Certificate of
Incorporation.

SECTION 6.03  Seal.  The corporate seal shall have inscribed thereon the words
              ----
"Corporate Seal," the year of incorporation and around the margin thereof the
words "Esperion Therapeutics, Inc. - Delaware."

SECTION 6.04  Waiver of Notice.  Whenever any notice is required to be given to
              ----------------
any stockholder or director of the Corporation under the provisions of the
General Corporation Law of the State of Delaware or these Bylaws, a waiver
thereof in writing, signed by the person or persons entitled to such notice,
whether before or after the time stated therein, shall be deemed equivalent to
the giving of such notice.  Neither the business to be transacted at, nor the
purpose of, any annual or special meeting of the stockholders or the Board of
Directors or committee thereof need be specified in any waiver of notice of such
meeting.

SECTION 6.05  Audits.  The accounts, books and records of the Corporation shall
              ------
be audited upon the conclusion of each fiscal year by an independent certified
public accountant selected by the Board of Directors, and it shall be the duty
of the Board of Directors to cause such audit to be done annually.

SECTION 6.06  Resignations.  Any director or any officer, whether elected or
              ------------
appointed, may resign at any time by giving written notice of such resignation
to the Chairman of the Board, the President, or the Secretary, and such
resignation shall be deemed to be effective as of the close of business on the
date said notice is received by the Chairman of the Board, the President, or the
Secretary, or at such later time as is specified therein.  No formal action
shall be required of the Board of Directors or the stockholders to make any such
resignation effective.

SECTION 6.07  Indemnification and Insurance.
              -----------------------------

         (A)  Each person who was or is made a party or is threatened to be made
a party to or is involved in any action, suit, or proceeding, whether civil,
criminal, administrative or investigative (hereinafter a "proceeding"), by
reason of the fact that he or she or a person of whom he or she is the legal
representative is or was a director or officer of the Corporation or is or was
serving at the request of the Corporation as a director, officer, employee or
agent of another corporation or of a partnership, joint venture, trust or other
enterprise, including service with respect to employee benefit plans maintained
or sponsored by the Corporation, whether the basis of such proceeding is alleged
action in an official capacity as a director, officer, employee or agent or in
any other capacity while serving as a director, officer, employee or agent,
shall be indemnified and held harmless by the Corporation to the fullest extent
authorized by the General Corporation Law of the State of Delaware as the same
exists or may hereafter be amended (but, in the case of any such amendment, only
to the extent that such amendment permits the Corporation to provide broader
indemnification rights than said

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<PAGE>

law permitted the Corporation to provide prior to such amendment), against all
expense, liability and loss (including attorneys' fees, judgments, fines, ERISA
excise taxes or penalties and amounts paid or to be paid in settlement)
reasonably incurred or suffered by such person in connection therewith and such
indemnification shall continue as to a person who has ceased to be a director,
officer, employee or agent and shall inure to the benefit of his or her heirs,
executors and administrators; provided, however, that except as provided in
paragraph (C) of this Bylaw, the Corporation shall indemnify any such person
seeking indemnification in connection with a proceeding (or part thereof)
initiated by such person only if such proceeding (or part thereof) was
authorized by the Board of Directors. The right to indemnification conferred in
this Bylaw shall be a contract right and shall include the right to be paid by
the Corporation the expenses incurred in defending any such proceeding in
advance of its final disposition, such advances to be paid by the Corporation
within 20 days after the receipt by the Corporation of a statement or statements
from the claimant requesting such advance or advances from time to time;
provided, however, that if the General Corporation Law of the State of Delaware
requires, the payment of such expenses incurred by a director or officer in his
or her capacity as a director or officer (and not in any other capacity in which
service was or is rendered by such person while a director or officer,
including, without limitation, service to an employee benefit plan) in advance
of the final disposition of a proceeding, shall be made only upon delivery to
the Corporation of an undertaking by or on behalf of such director or officer,
to repay all amounts so advanced if it shall ultimately be determined that such
director or officer is not entitled to be indemnified under this Bylaw or
otherwise.

         (B)  To obtain indemnification under this Bylaw, a claimant shall
submit to the Corporation a written request, including therein or therewith such
documentation and information as is reasonably available to the claimant and is
reasonably necessary to determine whether and to what extent the claimant is
entitled to indemnification. Upon written request by a claimant for
indemnification pursuant to the first sentence of this paragraph (B), a
determination, if required by applicable law, with respect to the claimant's
entitlement thereto shall be made as follows: (1) if requested by the claimant,
by Independent Counsel (as hereinafter defined), or (2) if no request is made by
the claimant for a determination by Independent Counsel, (i) by the Board of
Directors by a majority vote of a quorum consisting of Disinterested Directors
(as hereinafter defined), or (ii) if a quorum of the Board of Directors
consisting of Disinterested Directors is not obtainable or, even if obtainable,
such quorum of Disinterested Directors so directs, by Independent Counsel in a
written opinion to the Board of Directors, a copy of which shall be delivered to
the claimant, or (iii) if a quorum of Disinterested directors so directs, by the
stockholders of the Corporation. In the event the determination of entitlement
to indemnification is to be made by Independent Counsel at the request of the
claimant, the Independent Counsel shall be selected by the Board of Directors
unless there shall have occurred within two years prior to the date of the
commencement of the action, suit or proceeding for which indemnification is
claimed a "Change of Control" as defined in the Corporation's 2000 Equity
Compensation Plan, in which case the Independent Counsel shall be selected by
the claimant unless the claimant shall request that such selection be made by
the Board of Directors. If it is so determined

                                       13
<PAGE>

that the claimant is entitled to indemnification, payment to the claimant shall
be made within 10 days after such determination.

         (C)  If a claim under paragraph (A) of this Bylaw is not paid in full
by the Corporation within thirty days after a written claim pursuant to
paragraph (B) of this Bylaw has been received by the Corporation, the claimant
may at any time thereafter bring suit against the Corporation to recover the
unpaid amount of the claim and, if successful in whole or in part, the claimant
shall be entitled to be paid also the expense of prosecuting such claim. It
shall be a defense to any such action (other than an action brought to enforce a
claim for expenses incurred in defending any proceeding in advance of its final
disposition where the required undertaking, if any is required, has been
tendered to the Corporation) that the claimant has not met the standard of
conduct which makes it permissible under the General Corporation Law of the
State of Delaware for the Corporation to indemnify the claimant for the amount
claimed, but the burden of proving such defense shall be on the Corporation.
Neither the failure of the Corporation (including its Board of Directors,
Independent Counsel or stockholders) to have made a determination prior to the
commencement of such action that indemnification of the claimant is proper in
the circumstances because he or she has met the applicable standard of conduct
set forth in the General Corporation Law of the State of Delaware, nor an actual
determination by the Corporation (including its Board of Directors, Independent
Counsel or stockholders) that the claimant has not met such applicable standard
of conduct, shall be a defense to the action or create a presumption that the
claimant has not met the applicable standard of conduct.

         (D)  If a determination shall have been made pursuant to paragraph (B)
of this Bylaw that the claimant is entitled to indemnification, the Corporation
shall be bound by such determination in any judicial proceeding commenced
pursuant to paragraph (C) of this Bylaw.

         (E)  The Corporation shall be precluded from asserting in any judicial
proceeding commenced pursuant to paragraph (C) of this Bylaw that the procedures
and presumptions of this Bylaw are not valid, binding and enforceable and shall
stipulate in such proceeding that the Corporation is bound by all the provisions
of this Bylaw.

         (F)  The right to indemnification and the payment of expenses incurred
in defending a proceeding in advance of its final disposition conferred in this
Bylaw shall not be exclusive of any other right which any person may have or
hereafter acquire under any statute, provision of the Certificate of
Incorporation, Bylaws, agreement, vote of stockholders or Disinterested
Directors or otherwise. No repeal or modification of this Bylaw shall in any way
diminish or adversely affect the rights of any director, officer, employee or
agent of the Corporation hereunder in respect of any occurrence or matter
arising prior to any such repeal or modification.

         (G)  The Corporation may maintain insurance, at its expense, to protect
itself and any director, officer, employee or agent of the Corporation or
another corporation, partnership, joint venture, trust or other enterprise
against any expense,

                                       14
<PAGE>

liability or loss, whether or not the Corporation would have the power to
indemnify such person against such expense, liability or loss under the General
Corporation Law of the State of Delaware. To the extent that the Corporation
maintains any policy or policies providing such insurance, each such director or
officer, and each such agent or employee to which rights to indemnification have
been granted as provided in paragraph (H) of this Bylaw, shall be covered by
such policy or policies in accordance with its or their terms to the maximum
extent of the coverage thereunder for any such director, officer, employee or
agent.

         (H)  The Corporation may, to the extent authorized from time to time by
the Board of Directors, grant rights to indemnification, and rights to be paid
by the Corporation the expenses incurred in defending any proceeding in advance
of its final disposition, to any employee or agent of the Corporation to the
fullest extent of the provisions of this Bylaw with respect to the
indemnification and advancement of expenses of directors and officers of the
Corporation.

         (I)  If any provision or provisions of this Bylaw shall be held to be
invalid, illegal or unenforceable for any reason whatsoever: (1) the validity,
legality and enforceability of the remaining provisions of this Bylaw
(including, without limitation, each portion of any paragraph of this Bylaw
containing any such provision held to be invalid, illegal or unenforceable, that
is not itself held to be invalid, illegal or unenforceable, that is not itself
held to be invalid, illegal or unenforceable) shall not in any way be affected
or impaired thereby; and (2) to the fullest extent possible, the provisions of
this Bylaw (including, without limitation, each such portion of any paragraph of
this Bylaw containing any such provision held to be invalid, illegal or
unenforceable) shall be construed so as to give effect to the intent manifested
by the provision held invalid, illegal or unenforceable.

         (J)  For purposes of this Bylaw:

   (1) "Disinterested Director" means a director of the Corporation who is not
       and was not a party to the matter in respect of which indemnification is
       sought by the claimant.

   (2) "Independent Counsel" means a law firm, a member of a law firm, or an
       independent practitioner, that is experienced in matters of corporation
       law and shall include any person who, under the applicable standards of
       professional conduct then prevailing, would not have a conflict of
       interest in representing either the Corporation or the claimant in an
       action to determine the claimant's rights under this Bylaw.

                                       15
<PAGE>

          (K)  Any notice, request or other communication required or permitted
to be given to the Corporation under this Bylaw shall be in writing and either
delivered in person or sent by telecopy, telex, telegram, overnight mail or
courier service, or certified or registered mail, postage prepaid, return
receipt requested, to the Secretary of the Corporation and shall be effective
only upon receipt by the Secretary.

                                  ARTICLE VII


                           CONTRACTS, PROXIES, ETC.

SECTION 7.01  Contracts.  Except as otherwise required by law, the Certificate
              ---------
of Incorporation or these Bylaws, any contracts or other instruments may be
executed and delivered in the name and on the behalf of the Corporation by such
officer or officers of the Corporation as the Board of Directors may from time
to time direct.  Such authority may be general or confined to specific instances
as the Board may determine.  The Chairman of the Board, the President or any
Vice President may execute bonds, contracts, deeds, leases and other instruments
to be made or executed for or on behalf of the Corporation.  Subject to any
restrictions imposed by the Board of Directors or the Chairman of the Board, the
President or any Vice President of the Corporation may delegate contractual
powers to others under his jurisdiction, it being understood, however, that any
such delegation of power shall not relieve such officer of responsibility with
respect to the exercise of such delegated power.

SECTION 7.02  Proxies.  Unless otherwise provided by resolution adopted by the
              -------
Board of Directors, the Chairman of the Board, the President or any Vice
President may from time to time appoint an attorney or attorneys or agent or
agents of the Corporation, in the name and on behalf of the Corporation, to cast
the votes which the Corporation may be entitled to cast as the holder of stock
or other securities in any other corporation, any of whose stock or other
securities may be held by the Corporation, at meetings of the holders of the
stock or other securities of such other corporation, or to consent in writing,
in the name of the Corporation as such holder, to any action by such other
corporation, and may instruct the person or persons so appointed as to the
manner of casting such votes or giving such consent, and may execute or cause to
be executed in the name and on behalf of the Corporation and under its corporate
seal or otherwise, all such written proxies or other instruments as he may deem
necessary or proper in the premises.

                                       16
<PAGE>

                                 ARTICLE VIII

                                  AMENDMENTS

SECTION 8.01  Amendments.  These Bylaws may be altered, amended, or repealed at
              ----------
any meeting of the Board of Directors or of the stockholders, provided notice of
the proposed change was given in the notice of the meeting and, in the case of a
meeting of the Board of Directors, in a notice given not less than two days
prior to the meeting.

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