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                                                                     EXHIBIT 4.1


                           CERTIFICATE OF DESIGNATIONS

                                       of

                  SERIES A JUNIOR PARTICIPATING PREFERRED STOCK

                                       of

                                 ALLERGAN, INC.
                         (Pursuant to Section 151 of the
                        Delaware General Corporation Law)

                          -----------------------------

         Allergan, Inc., a corporation organized and existing under the General
Corporation Law of the State of Delaware (hereinafter called the "Corporation"),
hereby certifies that the following resolution was adopted by the Board of
Directors of the Corporation as required by Section 151 of the General
Corporation Law at a meeting duly called and held on January 25, 2000.

         RESOLVED, that pursuant to the authority granted to and vested in the
Board of Directors of this Corporation (hereinafter called the "Board of
Directors" or the "Board") in accordance with the provisions of the Certificate
of Incorporation of this Corporation, the Board of Directors hereby creates a
series of Preferred Stock, par value $.01 per share (the "Preferred Stock"), of
the Corporation and hereby states the designation and number of shares, and
fixes the relative rights, powers and preferences, and qualifications,
limitations and restrictions thereof as follows:

         Section 1. Designation and Amount. The shares of such series shall be
designated as "Series A Junior Participating Preferred Stock" (the "Series A
Preferred Stock") and the number of shares constituting the Series A Preferred
Stock shall be 1,500,000. Such number of shares may be increased or decreased by
resolution of the Board of Directors; PROVIDED, that no decrease shall reduce
the number of shares of Series A Preferred Stock to a number less than the
number of shares then outstanding plus the number of shares reserved for
issuance upon the exercise of outstanding options, rights or warrants or upon
the conversion of any outstanding securities issued by the Corporation
convertible into Series A Preferred Stock.

         Section 2. Dividends and Distributions.

         (A) Subject to the prior and superior rights of the holders of any
shares of any class or series of stock of this Corporation ranking prior and
superior to the Series A Preferred Stock with respect to dividends, the holders
of shares of Series A Preferred Stock, in preference to the holders of Common
Stock, par value $.01 per share (the "Common Stock"), of the Corporation, and of
any other stock ranking junior to the Series A Preferred Stock, shall be
entitled to receive, when, as and if declared by the Board of Directors out of
funds legally available for the purpose, quarterly dividends payable in cash on
the first day of March, June, September and December in each year (each such
date being referred to herein as

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a "Quarterly Dividend Payment Date"), commencing on the first Quarterly Dividend
Payment Date after the first issuance of a share or fraction of a share of
Series A Preferred Stock, in an amount per share (rounded to the nearest cent)
equal to the greater of (a) $1.00 or (b) subject to the provision for adjustment
hereinafter set forth, 100 times the aggregate per share amount of all cash
dividends, and 100 times the aggregate per share amount (payable in kind) of all
non-cash dividends or other distributions, other than a dividend payable in
shares of Common Stock or a subdivision of the outstanding shares of Common
Stock (by reclassification or otherwise), declared on the Common Stock since the
immediately preceding Quarterly Dividend Payment Date or, with respect to the
first Quarterly Dividend Payment Date, since the first issuance of any share or
fraction of a share of Series A Preferred Stock. In the event the Corporation
shall at any time declare or pay any dividend on the Common Stock payable in
shares of Common Stock, or effect a subdivision, combination or consolidation of
the outstanding shares of Common Stock (by reclassification or otherwise than by
payment of a dividend in shares of Common Stock) into a greater or lesser number
of shares of Common Stock, then in each such case the amount to which holders of
shares of Series A Preferred Stock were entitled immediately prior to such event
under clause (b) of the preceding sentence shall be adjusted by multiplying such
amount by a fraction, the numerator of which is the number of shares of Common
Stock outstanding immediately after such event and the denominator of which is
the number of shares of Common Stock that were outstanding immediately prior to
such event.

         (B) The Corporation shall declare a dividend or distribution on the
Series A Preferred Stock as provided in paragraph (A) of this Section 2
immediately after it declares a dividend or distribution on the Common Stock
(other than a dividend payable in shares of Common Stock); provided that, in the
event no dividend or distribution shall have been declared on the Common Stock
during the period between any Quarterly Dividend Payment Date and the next
subsequent Quarterly Dividend Payment Date, a dividend of $1.00 per share on the
Series A Preferred Stock shall nevertheless be payable on such subsequent
Quarterly Dividend Payment Date.

         (C) Dividends shall begin to accrue and be cumulative on outstanding
shares of Series A Preferred Stock from the Quarterly Dividend Payment Date next
preceding the date of issue of such shares, unless the date of issue of such
shares is prior to the record date for the first Quarterly Dividend Payment
Date, in which case dividends on such shares shall begin to accrue from the date
of issue of such shares, or unless the date of issue is a Quarterly Dividend
Payment Date or is a date after the record date for the determination of holders
of shares of Series A Preferred Stock entitled to receive a quarterly dividend
and before such Quarterly Dividend Payment Date, in either of which events such
dividends shall begin to accrue and be cumulative from such Quarterly Dividend
Payment Date. Accrued but unpaid dividends shall not bear interest. Dividends
paid on the shares of Series A Preferred Stock in an amount less than the total
amount of such dividends at the time accrued and payable on such shares shall be
allocated pro


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rata on a share-by-share basis among all such shares at the time outstanding.
The Board of Directors may fix a record date for the determination of holders of
shares of Series A Preferred Stock entitled to receive payment of a dividend or
distribution declared thereon, which record date shall be not more than 60 days
prior to the date fixed for the payment thereof.

         Section 3. Voting Rights. The holders of shares of Series A Preferred
Stock shall have the following voting rights:

         (A) Subject to the provision for adjustment hereinafter set forth, each
share of Series A Preferred Stock shall entitle the holder thereof to 100 votes
on all matters submitted to a vote of the stockholders of the Corporation. In
the event the Corporation shall at any time declare or pay any dividend on the
Common Stock payable in shares of Common Stock, or effect a subdivision,
combination or consolidation of the outstanding shares of Common Stock (by
reclassification or otherwise than by payment of a dividend in shares of Common
Stock) into a greater or lesser number of shares of Common Stock, then in each
such case the number of votes per share to which holders of shares of Series A
Preferred Stock were entitled immediately prior to such event shall be adjusted
by multiplying such number by a fraction, the numerator of which is the number
of shares of Common Stock outstanding immediately after such event and the
denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

         (B) Except as otherwise provided herein, in any other Certificate of
Designations creating a series of Preferred Stock or any similar stock, or by
law, the holders of shares of Series A Preferred Stock and the holders of shares
of Common Stock and any other capital stock of the Corporation having general
voting rights shall vote together as one class on all matters submitted to a
vote of stockholders of the Corporation.

         (C) Except as set forth herein, or as otherwise provided by law,
holders of Series A Preferred Stock shall have no special voting rights and
their consent shall not be required (except to the extent they are entitled to
vote with holders of Common Stock as set forth herein) for taking any corporate
action.

         Section 4. Certain Restrictions.

         (A) Whenever quarterly dividends or other dividends or distributions
payable on the Series A Preferred Stock as provided in Section 2 are in arrears,
thereafter and until all accrued and unpaid dividends and distributions, whether
or not declared, on shares of Series A Preferred Stock outstanding shall have
been paid in full, the Corporation shall not:

             (i) declare or pay dividends, or make any other distributions, on
         any shares of stock ranking junior (either as to dividends or upon
         liquidation, dissolution or winding up) to the Series A Preferred
         Stock;


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             (ii) declare or pay dividends, or make any other distributions, on
         any shares of stock ranking on a parity (either as to dividends or upon
         liquidation, dissolution or winding up) with the Series A Preferred
         Stock, except dividends paid ratably on the Series A Preferred Stock
         and all such parity stock on which dividends are payable or in arrears
         in proportion to the total amounts to which the holders of all such
         shares are then entitled;

             (iii) redeem or purchase or otherwise acquire for consideration
         shares of any stock ranking junior (either as to dividends or upon
         liquidation, dissolution or winding up) to the Series A Preferred
         Stock, provided that the Corporation may at any time redeem, purchase
         or otherwise acquire shares of any such junior stock in exchange for
         shares of any stock of the Corporation ranking junior (both as to
         dividends and upon dissolution, liquidation or winding up) to the
         Series A Preferred Stock; or

             (iv) redeem or purchase or otherwise acquire for consideration any
         shares of Series A Preferred Stock, or any shares of stock ranking on a
         parity with the Series A Preferred Stock, except in accordance with a
         purchase offer made in writing or by publication (as determined by the
         Board of Directors) to all holders of such shares upon such terms as
         the Board of Directors, after consideration of the respective annual
         dividend rates and other relative rights and preferences of the
         respective series and classes, shall determine in good faith will
         result in fair and equitable treatment among the respective series or
         classes.

         (B) The Corporation shall not permit any subsidiary of the Corporation
to purchase or otherwise acquire for consideration any shares of stock of the
Corporation unless the Corporation could, under paragraph (A) of this Section 4,
purchase or otherwise acquire such shares at such time and in such manner.

         Section 5. Reacquired Shares. Any shares of Series A Preferred Stock
purchased or otherwise acquired by the Corporation in any manner whatsoever
shall be retired and canceled promptly after the acquisition thereof. All such
shares shall upon their cancellation become authorized but unissued shares of
Preferred Stock and may be reissued as part of a new series of Preferred Stock
subject to the conditions and restrictions on issuance set forth herein, in the
Certificate of Incorporation, or in any other Certificate of Designations
creating a series of Preferred Stock or any similar stock or as otherwise
required by law.

         Section 6. Liquidation, Dissolution or Winding Up.

         (A) Upon any liquidation, dissolution or winding up of the Corporation,
voluntary or otherwise no distribution shall be made (1) to the holders of
shares of stock ranking junior (either as to dividends or upon liquidation,
dissolution or winding up) to the Series A Preferred Stock unless, prior
thereto, the holders of shares of Series A Preferred Stock shall have received
an amount per share (the "Series A Liquidation Preference") equal to $100 per


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share, plus an amount equal to accrued and unpaid dividends and distributions
thereon, whether or not declared, to the date of such payment, provided that the
holders of shares of Series A Preferred Stock shall be entitled to receive an
aggregate amount per share, subject to the provision for adjustment hereinafter
set forth, equal to 100 times the aggregate amount to be distributed per share
to holders of shares of Common Stock, or (2) to the holders of shares of stock
ranking on a parity (either as to dividends or upon liquidation, dissolution or
winding up) with the Series A Preferred Stock, except distributions made ratably
on the Series A Preferred Stock and all such parity stock in proportion to the
total amounts to which the holders of all such shares are entitled upon such
liquidation, dissolution or winding up. In the event the Corporation shall at
any time declare or pay any dividend on the Common Stock payable in shares of
Common Stock, or effect a subdivision, combination or consolidation of the
outstanding shares of Common Stock (by reclassification or otherwise than by
payment of a dividend in shares of Common Stock) into a greater or lesser number
of shares of Common Stock, then in each such case the aggregate amount to which
holders of shares of Series A Preferred Stock were entitled immediately prior to
such event under the proviso in clause (1) of the preceding sentence shall be
adjusted by multiplying such amount by a fraction the numerator of which is the
number of shares of Common Stock outstanding immediately after such event and
the denominator of which is the number of shares of Common Stock that are
outstanding immediately prior to such event.

         (B) In the event, however, that there are not sufficient assets
available to permit payment in full of the Series A Liquidation Preference and
the liquidation preferences of all other classes and series of stock of the
Corporation, if any, that rank on a parity with the Series A Preferred Stock in
respect thereof, then the assets available for such distribution shall be
distributed ratably to the holders of the Series A Preferred Stock and the
holders of such parity shares in proportion to their respective liquidation
preferences.

         (C) Neither the merger or consolidation of the Corporation into or with
another corporation nor the merger or consolidation of any other corporation
into or with the Corporation shall be deemed to be a liquidation, dissolution or
winding up of the Corporation within the meaning of this Section 6.

         Section 7. Consolidation, Merger, etc. In case the Corporation shall
enter into any consolidation, merger, combination or other transaction in which
the shares of Common Stock are exchanged for or changed into other stock or
securities, cash and/or any other property, then in any such case each share of
Series A Preferred Stock shall at the same time be similarly exchanged or
changed into an amount per share, subject to the provision for adjustment
hereinafter set forth, equal to 100 times the aggregate amount of stock,
securities, cash and/or any other property (payable in kind), as the case may
be, into which or for which each share of Common Stock is changed or exchanged.
In the event the Corporation shall at any time declare or pay any dividend on
the Common Stock payable in shares of Common Stock, or effect a subdivision,
combination or consolidation of the outstanding shares of Common Stock (by


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reclassification or otherwise than by payment of a dividend in shares of Common
Stock) into a greater or lesser number of shares of Common Stock, then in each
such case the amount set forth in the preceding sentence with respect to the
exchange or change of shares of Series A Preferred Stock shall be adjusted by
multiplying such amount by a fraction, the numerator of which is the number of
shares of Common Stock outstanding immediately after such event and the
denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

         Section 8. No Redemption. The shares of Series A Preferred Stock shall
not be redeemable by the Company.

         Section 9. Rank. The Series A Preferred Stock shall rank, with respect
to the payment of dividends and the distribution of assets upon liquidation,
dissolution or winding up, junior to all series of any other class of the
Corporation's Preferred Stock, except to the extent that any such other series
specifically provides that it shall rank on a parity with or junior to the
Series A Preferred Stock.

         Section 10. Amendment. At any time any shares of Series A Preferred
Stock are outstanding, the Certificate of Incorporation of the Corporation shall
not be amended in any manner which would materially alter or change the powers,
preferences or special rights of the Series A Preferred Stock so as to affect
them adversely without the affirmative vote of the holders of at least
two-thirds of the outstanding shares of Series A Preferred Stock, voting
separately as a single class.

         Section 11. Fractional Shares. Series A Preferred Stock may be issued
in fractions of a share that shall entitle the holder, in proportion to such
holder's fractional shares, to exercise voting rights, receive dividends,
participate in distributions and to have the benefit of all other rights of
holders of Series A Preferred Stock.

         IN WITNESS WHEREOF, this Certificate of Designations is executed on
behalf of the Corporation by its Corporate Vice President - Administration,
General Counsel and Secretary, this 28th day of January, 2000.


                                  /s/ Francis R. Tunney, Jr.
                                  ----------------------------------------------
                                      Francis R. Tunney, Jr.,
                                      Corporate Vice President - Administration,
                                      General Counsel and Secretary


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