Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 08, 2022
Cover [Abstract]
Entity Registrant Name	SIENTRA, INC.
Entity Central Index Key	0001551693
Document Type	10-Q
Document Period End Date	Jun. 30, 2022
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		62,774,510
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Trading Symbol	SIEN
Title of 12(b) Security	Common Stock, par value $0.01 per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-36709
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-5551000
Entity Address, Address Line One	420 South Fairview Avenue
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Santa Barbara
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	93117
City Area Code	805
Local Phone Number	562-3500
Document Quarterly Report	true
Document Transition Report	false