For Immediate Release

Senomyx, Inc. Files registration statement for proposed initial public offering of common stock

March 29, 2004

LA JOLLA, CA Senomyx, Inc. announced today that it has filed with the Securities and Exchange Commission a registration statement relating to the proposed initial public offering of its common stock. It is expected that all of the stock will be sold by Senomyx.

Citigroup will be acting as the sole book-runner of this offering.Deutsche Bank Securities will be a co-lead manager.Needham & Company, Inc. and First Albany Capital will be co-managers of the offering.

Senomyx is the leading biotechnology company using proprietary taste receptor-based assays and screening technologies to discover and develop novel flavors and flavor enhancers for the packaged food and beverage industry. Senomyx has entered into product discovery and development collaborations with four of the world's leading packaged food and beverage companies: Campbell Soup Company, The Coca-Cola Company, Kraft Foods Global, Inc. and Nestl_ SA. Senomyx's current programs focus on the development of flavors or flavor enhancers in three taste areas, including savory, sweet and salt.

A registration statement relating to these securities has been filed with the Securities and Exchange Commission but has not yet become effective. These securities may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective. This press release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

The offering will be made only by means of a prospectus, a copy of which may be obtained when available, from Citigroup (Prospectus Department, 140 58th Street, Brooklyn, NY 11220, phone 718. 765.6732).

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