SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                               ------------------
                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                        PURSUANT TO RULE 13a-16 OR 15d-16
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               ------------------
                           For the month of June 2004

                        Commission File Number: 001-31368

                                SANOFI-SYNTHELABO
                 (Translation of registrant's name into English)

                   174, avenue de France, 75013 Paris, FRANCE
                    (Address of principal executive offices)

         Indicate by check mark whether the registrant files or will file annual
reports under cover Form 20-F or Form 40-F.

                    Form 20-F     [X]              Form 40-F  [ ]

         Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(1):_____


         Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101(b)(7):_____


         Indicate by check mark whether the registrant by furnishing the
information contained in this Form is also thereby furnishing the information to
the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of
1934.

                      Yes  [ ]                      No  [X]

         If "Yes" marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2(b):  82-________


         This Report on Form 6-K shall be deemed to be incorporated by reference
into  Sanofi-Synthelabo's  Registration  Statement on Form F-4 (Registration No.
333-112314),  as post-effectively amended and declared effective on May 13, 2004
by the United States Securities Exchange Commission, and the related prospectus,
dated April 9, 2004, and the  prospectus  supplement,  dated May 27, 2004,  each
filed pursuant to Rule 424(b) under the United States Securities Act of 1933, as
amended,  and shall be part thereof from the date on which this Report is filed,
to the extent not  superseded  by  documents  or reports  subsequently  filed or
furnished.





                                                        [SANOFI-SYNTHELABO LOGO]


[Graphic] Investor Relations


                      SANOFI-SYNTHELABO'S OFFER FOR AVENTIS
                            EXPIRATION DATE OF OFFERS

PARIS,  FRANCE -- JUNE 1, 2004 -- On June 1,  2004,  the  Autorite  des  marches
financiers  (AMF) -- the French stock market  regulator--  announced that it had
set June 30, 2004 as the expiration  date of  Sanofi-Synthelabo's  (PARIS:  SAN,
NYSE:  SNY)  revised  offer for the  ordinary  shares of  Aventis  (PARIS:  AVE,
FRANKFURT: AVE.ETR, NYSE: AVE).

Accordingly,  Sanofi-Synthelabo  confirms  that the French  offer and the German
offer will expire at 23:00 hr (Central European Summer Time), and the U.S. offer
will expire  simultaneously  at 5:00 p.m. (Eastern Daylight Time), on Wednesday,
June 30, 2004.

Sanofi-Synthelabo  confirms that holders of Aventis  securities  may tender,  or
withdraw their tendered,  Aventis securities at any time until the expiration of
the offers.


In accordance with article 7 of the COB rule no. 2002-04, this press release was
transmitted to the Autorite des marches financiers (AMF) before its publication.

IMPORTANT  INFORMATION:  In connection with the proposed acquisition of Aventis,
Sanofi-Synthelabo  has  filed a  registration  statement  on Form F-4  (File no.
333-112314),  including a prospectus and a prospectus supplement relating to the
revised offer,  and will file additional  documents with the SEC.  INVESTORS ARE
URGED TO READ THE  REGISTRATION  STATEMENT,  INCLUDING  THE  PROSPECTUS  AND THE
PROSPECTUS  SUPPLEMENT  RELATING TO THE REVISED  OFFER,  AND ANY OTHER  RELEVANT
DOCUMENTS FILED WITH THE SEC, INCLUDING ALL AMENDMENTS AND SUPPLEMENTS,  BECAUSE
THEY CONTAIN IMPORTANT INFORMATION.  Free copies of the registration  statement,
as well as other relevant  documents  filed with the SEC, may be obtained at the
SEC's web site at  www.sec.gov.  The prospectus  and the  prospectus  supplement
relating to the revised offer and other transaction-related  documents are being
mailed to Aventis security holders eligible to participate in the U.S. offer and
additional  copies may be obtained for free from MacKenzie  Partners,  Inc., the
information  agent for the U.S. offer, at the following  address:  105,  Madison
Avenue, New York, New York 10016; telephone:  1-(212) 929-5500 (call collect) or
1-(800) 322-2885 (toll-free call); e-mail proxy@mackenziepartners.com.

In France,  holders of Aventis  securities  are  requested,  with respect to the
offer,   to   refer   to   the   prospectus   supplement   (note   d'information
complementaire),  which has been granted VISA number  04-384 by the Autorite des
marches  financiers  ("AMF")  and which is  available  on the website of the AMF
(www.amf-france.org)  and without cost from:  BNP Paribas  Securities  Services,
GIS-Emetteurs,  Service Logistique, Les Collines de l'Arche, 75450 Paris Cedex 9
and to the  recommendation  statement (note  d'information en reponse) which has
been granted visa number 04-510.



The public offer to holders of Aventis  ordinary  shares located in Germany (the
"German  Offer")  is being made in  accordance  with  applicable  German law and
pursuant  to an offer  document/sales  prospectus,  which is  available  free of
charge at BNP Paribas Securities Services, Gruneburgweg 14, D-60322 Frankfurt am
Main   (Fax:   069  -  152  05  277)  and  on  the   website   of  the   Company
(www.sanofi-synthelabo.com).  Any decision to tender Aventis  ordinary shares in
exchange for  Sanofi-Synthelabo  ordinary  shares under the German Offer must be
taken  exclusively  with regard to the terms and conditions of the German Offer,
as well as with regard to the information  included in the offer  document/sales
prospectus, including any amendments thereto, issued in Germany.

The  French  Offer,  the U.S.  Offer and the  German  Offer  are  being  made on
substantially  the same terms and  completion  of these offers is subject to the
same  conditions.  It is intended  that the three offers will expire at the same
time.

Investors  and  security  holders  may obtain a free copy of the Form 20-F filed
with the SEC on April 2, 2004 and any other documents filed by Sanofi-Synthelabo
with the SEC at www.sec.gov as well as of the Reference  Document filed with the
AMF on April 2, 2004 (No. 04-0391) at  www.amf-france.org or directly from
Sanofi-Synthelabo on our web site at: www.sanofi-synthelabo.com.




INVESTOR RELATIONS DEPARTMENT
Philippe Goupit         Director of Investor Relations
Arnaud Delepine         Investor Relations Europe
Sanjay Gupta            Investor Relations US
Anne d'Halluin-Sulzer   Investor Relations

CONTACTS:
E-mail: investor-relations@sanofi-synthelabo.com
EUROPE                        US
Tel: + 33 1 53 77 45 45       Tel: + 1 212 551 42 93
Fax: + 33 1 53 77 42 96       Fax: + 1 212 551 49 92





                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.


Dated: June 1, 2004                     SANOFI-SYNTHELABO


                                         By:         /S/ MARIE-HELENE LAIMAY
                                            ------------------------------------
                                              Name:    Marie-Helene Laimay
                                              Title:   Senior Vice President and
                                                       Chief Financial Officer