{\rtf1\ansi\ansicpg1252\uc1\deff0\deflang1033 {\colortbl\red0\green0\blue0;\red204\green6\blue42;\red204\green238\blue255;\red128\green128\blue128;}{\fonttbl{\f2\fswiss Arial;}{\f1\fmodern Courier New;}{\f3\fdecor Symbol;}{\f0\froman Times New Roman;}{\f4\fnil Wingdings;}} {\info{\subject EDGAR Online Pro}{\version3}{\*\company EDGAR Online, a division of Donnelley Financial Solutions}{\author EDGAR Online HTML to RTF Converter. Version 3.0}{\*\category \0001193125-21-032316.html.ecq}{\doccomm Source: EDGAR Online, a division of Donnelley Financial Solutions \'a9 Copyright 2021. All rights reserved.}{\title Sientra, Inc. (Form: 424B5, Received: 02/08/2021 16:03:11)}} \paperh15840\paperw12240\margl360\margr360\margt360\margb360\headery0\footery0\sprstsp\sprsbsp\sprsspbf\sprslnsp\widowctrl\viewscale100 {\*\bkmkstart BKMK_1}{\*\bkmkend BKMK_1}{\*\bkmkstart BKMK_2}{\*\bkmkend BKMK_2}{\*\bkmkstart BKMK_3}{\*\bkmkend BKMK_3}{\*\bkmkstart BKMK_4}{\*\bkmkend BKMK_4}\pard {\fs14\b {\field\fldedit{\*\fldinst { HYPERLINK "" \\l "BKMK_5"}}{\fldrslt\ul {Table of Contents}}}}\par \pard \qr \li250\ri250\sb210 {\fs18 {\b Filed Pursuant to Rule 424(b)(5)\line Registration No. 333-231288}}{\*\bkmkstart BKMK_6}{\*\bkmkend BKMK_6}\par \pard \qc \li250\ri250 {\fs18 {\cf1 {\b SUBJECT TO COMPLETION, DATED FEBRUARY 8, 2021}}}\par \pard \li250\ri250 {\fs14 \u160?}\par \pard \li250\ri250 {\fs17 {\cf1 The information in this preliminary prospectus supplement is not complete and may be changed. Neither this preliminary prospectus supplement nor the accompanying prospectus is an offer to sell these securities, and we are not soliciting an offer to buy these securities, in any jurisdiction where the offer or sale is not permitted.}}\par \pard \li250\ri250 {\fs14 \u160?}\par \pard \li250\ri250\sb324 {\fs20 {\b PRELIMINARY PROSPECTUS SUPPLEMENT}}\par \pard \li250\ri250 {\fs20 {\b (To prospectus dated May\u160?22, 2019)}}\par \pard \li250\ri250 {\fs8 \u160?}\par \pard \brdrb\brdrs\brdrw18\brdrcf0 \li250\ri250 {\fs18 \u160?}\par \pard \li250\ri250\sb54 {\fs18 \u160?}\par \pard \li250\ri250 {\fs18 \u160?}\par \pard \qc \li250\ri250 {\fs18 {\pict\jpegblip\pichgoal418\picwgoal1795\bin3930 JFIF C C 8 !1"Qa#q%&')23ABc 0 !1AQaq2"R ? Ǣ)7gb{f`좒jș\x3&F 9$oaՋRuiw/O ,R(tGL:Q7^ilhPËK;LMHntt73J!˷x#'ʵjzLSB,vNȘ1"D|(FaZ{1mv@Q˫Su%XgW+@L?; r>AyS+;sy^q_5Pi:-"bz5NbISԦ.&*dE6Nt:qGWjjV^J 6NP@K;7f2R Ah"^R)z"l݀Sk}XZqLb1в8?#8_q#gG`Dݕ cn % DT]_XŶpVyP {##LFbE[ODSE=ODHOWPyCniؚܹ,yMw?&elR7HES8`M6S$g6J|k$Т29VwƜ3nt#u4Vt g1\( ax(yq19:òl!{witjt; iU9#Q[# EE ZL'aZ/cą&NKma gDw$ҕČ5hacJ1ICepb5XƌVm%$a͝E[۰hCSX;Q,lʦ̃8T`BXL6ijah鞽htgݗƻJкeM4|w!ᠢ'M m)j uy`ٝ zuDԻyZnP@5{']ې0YDsA"aM:0"d'?[KocDxO|y%fkEӅl7U[5tR6dO==DPʫ,M79bevlv;p>LMuVԜ巧%ɮ*E~!q3Aʎ]w`ig+JHs)uorHuH (q[ׯg </gg!Ͳ>irIܱb|[쯎%Xdfn0d lVf+I dؒҔ:upy"p_3trڷfE_+w}h@2P]dN}Ύd6%BW*=aԾbssfQ+"n>gmS5gNjхM[!aRV($#II YN~\ESwf~B{2mʩEهR͉n]rjRXd Lf|!&҇p}ű8ka%kNkz5`uWH:9iႺHHIR5