Pursuant to the requirement set forth in Rule
13a-14(b) of the Securities Exchange Act of 1934, as amended (the Exchange Act), and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. Section 1350), Ronald W. Barrett, Chief Executive Officer of
XenoPort, Inc. (the Company), and William G. Harris, Senior Vice President of Finance and Chief Financial Officer of the Company, each hereby certifies that, to the best of his knowledge:
1. The Companys Quarterly Report on Form 10-Q for the period ended September 30, 2009, to which this Certification is attached as Exhibit 32.1
(the Periodic Report), fully complies with the requirements of Section 13(a) or 15(d) of the Exchange Act, and
information contained in the Periodic Report fairly presents, in all material respects, the financial condition and results of operations of the Company.
In Witness Whereof, the undersigned have set their hands hereto as of the 4th day of November, 2009.
/s/ RONALD W. BARRETT
|Ronald W. Barrett|
|Chief Executive Officer and Director|
/s/ WILLIAM G. HARRIS
|William G. Harris|
|Senior Vice President of Finance and Chief Financial Officer|
||This certification accompanies the quarterly report on Form 10-Q to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be
incorporated by reference into any filing of XenoPort, Inc. under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether made before or after the date of the Form 10-Q), irrespective of any
general incorporation language contained in such filing. |