X0306 4 2021-02-02 0 0001551693 Sientra, Inc. SIEN 0001749385 Little Paul Sean 420 SOUTH FAIRVIEW AVENUE, SUITE 200 SANTA BARBARA CA 93117 0 1 0 0 Chief Financial Officer Common Stock 2021-02-02 4 S 0 4123 4.913 D 131836 D Sale of shares to satisfy the Reporting Person's tax withholding obligation upon the vesting of 10,000 Restricted Stock Units (RSUs). The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $4.88 to $4.96, inclusive. The Reporting Person undertakes to provide to Sientra, Inc., any security holder of Sientra, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4. /s/ Oliver Bennett, Attorney-in-Fact 2021-02-03