Exhibit 4.1

MEDIVATION, INC . COMMON STOCK NUMBER MED 0746 SHARES THIS CERTIFIES THAT SPECIMEN is the record holder of INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE CUSIP 5850LN 10 L SEE REVERSE FOR CERTAIN DEFINITIONS FULLY PAID AND NON-ASSESSABLE SHARES OF COMMON STOCK, $0.01 PAR VALUE PER SHARE, OF MEDIVATION, INC . transferable on the books of the Corporation in person or by duly authorized attorney upon surrender of this Certificate properly endorsed. This Certificate is not valid until countersigned by the Transfer Agent and registered by the Registrar. WITNESS the facsimile signatures of its duly authorized officers. DATED: ASSISTANT SECRETARY PRESIDENT AND CHIEF EXECUTIVE OFFICER COUNTERSIGNED AND REGISTERED AMERICAN STOCK TRANSFER AND TRUST COMPANY (New York, Newyork) By Transfer agent and Registrant Authorized Signature

MEDIVATION, INC.

The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations:

TEN COM	–	as tenants in common	UNIF GIFT MIN ACT-                                              Custodian
TEN ENT	–	as tenants by the entireties		(Cust)		(Minor)
JT TEN	–	as joint tenants with right of survivorship and not as tenants in common		under Uniform Gifts to Minors
				Act
				(state)
			UNlF TRF MIN ACT-		Custodian (until age             )
				(Cust)
				under UniformTransfers
				(Minor)
				to Minors Act
				(State)

Additional abbreviations may also be used though not in the above list.

For Value received,                                                                                                                                     hereby sell, assign and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER

IDENTIFYING NUMBER OF ASSIGNEE

(PLEASE PRINT OR TYPRWRITE NAME AND ADDRESS, INCLUDING ZIP CODE OF ASSIGNEE)

	Shares
of the Common Stock represented by the within Certificate, and do(es) hereby irrevocably constitute and appoint

	Attorney
to transfer the said stock on the books of the within named Corporation with full power of substitution in the premises.

Dated	X
	X
	NOTICE:	THE SIGNATURE(S) TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME(S) AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATEVER.

SIGNATURES GUARANTEED:

By
	THE SIGNATURE(S) MUST BE AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15.

This certificate also evidences and entitles the holder hereof to certain rights as set forth in an Agreement between Medivation, Inc. (the “Company”) and American Stock Transfer & Trust Company, as Rights Agent, dated as of December 4, 2006, as the same may be amended from time to time (the “Agreement”), the terms of which are hereby incorporated herein by reference and a copy of which is on file at the principal executive offices of the Company. Under certain circumstances, as set forth in the Agreement, such Rights will be evidenced by separate certificates and will no longer be evidenced by this certificate. The Company will mail to the holder of this certificate a copy of the Agreement without charge after receipt of a written request therefor. As described in the Agreement, Rights which are owned by, transferred to or have been owned by Acquiring Persons or Associates or Affiliates thereof (as defined in the Agreement) shall become null and void and will no longer be transferable.