Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * RASTETTER WILLIAM H	2. Issuer Name and Ticker or Trading Symbol Receptos, Inc. [ RCPT ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __ X __ Director                      _____ 10% Owner _____ Officer (give title below)      _____ Other (specify below)
(Last)          (First)          (Middle) 10835 ROAD TO THE CURE, SUITE 205	3. Date of Earliest Transaction (MM/DD/YYYY) 5/14/2013
(Street) SAN DIEGO, CA 92121 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	5/14/2013		C		113505	A	$5.25	193777	D
Common Stock	5/14/2013		C		67029	A	$7.73	260806	D
Common Stock	5/14/2013		P		71428	A	$14.00	71428	I	By Trust
Common Stock	5/14/2013		C		1152038	A	$5.25	1266322	I	See footnotes   (1) (2)
Common Stock	5/14/2013		C		550872	A	$7.73	1817194	I	See footnotes   (1) (2)
Common Stock	5/14/2013		P		265567	A	$14.00	2082761	I	See footnotes   (1) (2)

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Preferred Stock	$5.25	5/14/2013		C   (3)			851291	(3)	(3)	Common Stock	113505	$0	0	D
Series B Preferred Stock	$7.73	5/14/2013		C   (3)			502720	(3)	(3)	Common Stock	67029	$0	0	D
Series A Preferred Stock	$5.25	5/14/2013		C   (3)			8640289	(3)	(3)	Common Stock	1152038	$0	0	I	See footnotes   (1) (2)
Series B Preferred Stock	$7.73	5/14/2013		C   (3)			4131552	(3)	(3)	Common Stock	550872	$0	0	I	See footnotes   (1) (2)

Explanation of Responses:
( 1)	Beneficial ownership consists of: (i) 342,741 shares of common stock held by Venrock Associates V, L.P. ("Venrock Associates"); (ii) 29,058 shares of common stock held by Venrock Partners V, L.P. ("Venrock Partners"); (iii) 8,052 shares of common stock held by Venrock Entrepreneurs Fund V, L.P. ("Venrock Entrepreneurs"); (iv) an aggregate of 1,536,537 shares of common stock issued upon conversion of shares of Series A preferred stock and Series B preferred stock held by Venrock Associates; (v) an aggregate of 130,272 shares of common stock issued upon conversion of shares of Series A preferred stock and Series B preferred stock held by Venrock Partners; and (vi) an aggregate of 36,101 shares of common stock issued upon conversion of shares of Series A preferred stock and Series B preferred stock held by Venrock Entrepreneurs.
( 2)	The sole general partner of Venrock Associates is Venrock Management V, LLC ("Venrock Management V"). The sole general partner of Venrock Partners is Venrock Partners Management V, LLC ("Venrock Partners Management V"). The sole general partner of Venrock Entrepreneurs is VEF Management V, LLC ("VEF"). Venrock Management V, Venrock Partners Management V and VEF disclaim beneficial ownership over all shares held by Venrock Associates, Venrock Partners and Venrock Entrepreneurs, except to the extent of any pecuniary interest therein. Dr. Rastetter was formerly a consultant of an entity affiliated with the Venrock entities but does not have voting or investment control over the shares held by the Venrock entities. Dr. Rastetter has an indirect pecuniary interest in the investment held by the Venrock entities and expressly disclaims beneficial ownership of such shares, except to the extent of his indirect pecuniary interest therein.
( 3)	The Series A Preferred Stock converted upon the closing of the Issuer's initial public offering at a conversion ratio of 1 share of Common Stock for every 7.5 shares of Series A Preferred Stock, for no additional consideration.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
RASTETTER WILLIAM H 10835 ROAD TO THE CURE, SUITE 205 SAN DIEGO, CA 92121	X

Signatures
/s/ William Rastetter		5/14/2013
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.