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
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                      	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 *

Simon Nicholas	2. Issuer Name and Ticker or Trading Symbol

Sientra, Inc. [ SIEN ]	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)

420 SOUTH FAIRVIEW AVENUE, SUITE 200	3. Date of Earliest Transaction (MM/DD/YYYY)

6/5/2018		
(Street)

SANTA BARBARA, CA 93117
(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 (RSUs)  	6/5/2018  	 	A	  	6116   (1)	A	$20.44  	37662  	D  	 	
Common Stock  	 	 	 	  	 	 	 	2730765  	I  	See Note   (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					

Explanation of Responses:	
(1) 	The Common Stock underlying this grant of restricted stock will vest on the earlier to occur of: (i) the day prior to the annual meeting of stockholders for the year following the date of grant or (ii) the one (1) year anniversary of the annual meeting of stockholders of the year of grant, subject to continued service as a director of the Issuer.	
(2) 	Consists of 2,730,765 shares held of record by Clarus Lifesciences I, L.P. ("Clarus I"). Clarus Ventures I Management, L.P. ("Clarus I GPLP") is the sole general partner of Clarus I. Clarus Ventures I, LLC ("Clarus I GPLLC") is the sole general partner of Clarus I GPLP. Mr. Simon is a managing director of Clarus I GPLLC and may be deemed to beneficially own certain of the shares held of record by Clarus I. Mr. Simon disclaims beneficial ownership of all shares held of record by Clarus I, except to the extent of his pecuniary interest therein.	

Reporting Owners	
Reporting Owner Name / Address	Relationships	
	Director	10% Owner	Officer	Other	
Simon Nicholas
420 SOUTH FAIRVIEW AVENUE, SUITE 200
SANTA BARBARA, CA 93117	X				

Signatures		
/s/ Oliver Bennett, Attorney-in-Fact		6/7/2018	
** 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.	
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