#1sientra. INVESTOR PRESENTATION MAY 2021 1#2FORWARD-LOOKING STATEMENTS This presentation contains "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, relating to, among other things, the future performance of Sientra, Inc. (the "Company") that are based on management's current assumptions and expectations of future events and trends and involve risks and uncertainties. All statements other than statements of historical fact are forward-looking statements. The words "believe," "may," "might," "could," "will," "aim," "estimate," "continue," "anticipate," "intend," "expect," "plan," or the negative of those terms, and similar expressions that convey uncertainty of future events or outcomes are intended to identify estimates, projections and other forward-looking statements. Forward-looking statements are made only as of the date of this release. The words "believe," "may," "might," "could," "will," "aim," "estimate," "continue, "anticipate,” “intend," "expect," "plan," "position," or the negative of those terms, and similar expressions that convey uncertainty of future events or outcomes are intended to identify estimates, projections and other forward-looking statements. Forward-looking statements may include information concerning the Company's priorities for 2021, the impact of the COVID-19 pandemic on the Company and its operations, the Company's possible or assumed future results of operations, including descriptions of the Company's revenues, profitability, outlook and overall business strategy. Such statements are subject to risks and uncertainties, including the closing and audit of the Company's financial statements which audit is not yet complete and the preliminary estimates presented here could differ from the final audited financial statements presented by the Company, the scope and duration of the COVID-19 pandemic, the Company's ability to recapture delayed procedures resulting from the COVID-19 pandemic, the positive reaction from plastic surgeons and their patients to the Company's products, the ability to meet consumer demand, the growth of the sale of bioTips, and the Company's ability to manage its operating expenses and cash balance. Additional factors that could cause actual results to differ materially from those contemplated in this presentation can be found in the Risk Factors section of the Company's public filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, and such estimates, projections and other forward-looking statements speak only as of the date they were made, and, except to the extent required by law, the Company undertakes no obligation to update or review any estimate, projection or forward-looking statement. Actual results may differ from those set forth in this presentation due to the risks and uncertainties inherent in the Company's business. sientra. 2#3sientra. REIMAGINING WHAT'S POSSIBLE IN PLASTIC SURGERY To be the leader of transformative treatments and technologies vision / focused on progressing the art of plastic surgery Offer proprietary innovations and unparalleled partnerships mission / that radically advance how plastic surgeons think, work and care for their patients 33#4GROWTH DRIVERS FUTURE GROWTH DRIVEN BY SINGULAR FOCUS ON PLASTIC SURGEONS Customer Centricity Focus on developing proprietary innovations and partnerships that advance how plastic surgeons care for their patients Cultivate customer relationships and advance Sientra brand by building on commitment to surgeons and the patients they treat, and by actively promoting clinical data & industry leading warranty program Build upon highly efficient sales team to drive organic growth within and amongst practices & hospitals with goal to be a top 2 implants and expander company in the US market Innovation Focus on becoming more competitive with treatments and technologies focused on progressing the art of plastic surgery . Continue to develop products that extend or evolve Sientra's core offerings that maximize relevance in the future environment TAM Expansion Drive market share in Japan by expanding choice of products and complete near-term expansion into Canadian market Evaluate and enter incremental international markets Identify additional opportunities for inorganic growth within the U.S. plastic surgery market Efficiency & Productivity Establish a company-wide culture of focus and accountability Make disciplined investments to drive productivity, operating leverage, and margin expansion sientra. 4#5INVESTMENT THESIS STRONG PRODUCT PORTFOLIO ROBUST SAFETY AND CLINICAL DATA FOCUSED COMMERCIAL MODEL • • • · · Comprehensive portfolio of 5th generation silicone gel breast implants Strong tissue expander portfolio with health and economic benefits Safety profile supported by robust 10-year data¹ Backed by leading Platinum20TM warranty program Uniquely focused on breast aesthetics and the plastic surgery channel Expanded sales and marketing efforts dedicated to driving patients to plastic surgery customers • Focused on continuing to expand hospital account base through 2021 IMMEDIATE TAM GROWTH OPPORTUNITY2 MULTIPLE TAM EXPANSION OPPORTUNITIES · • $600 million immediately addressable TAM (US Augmentation and Reconstruction + Japan) Large growth drivers through deeper and broader account penetration • Significant OUS market opportunity (Canada approval anticipated in 2021) Product innovation and development to drive new growth • CLEAR PATH TO PROFITABILITY • Exited 10'21 with strong momentum of 47% YoY growth for Breast Products segment Organizational structure optimized to increase operating leverage • Divested mira Dry business to 1315 Capital 1 Stevens WG, Calobrace MB, Alizadeh A, Zeidler KR, Harrington JL, d'Incelli RC. Ten-year core study data for Sientra's Food and Drug Administration - approved round and shaped breast implants with cohesive silicone gel. Plast Reconstr Surg. 2018;141(4S):7S-19S; sientra. 2 Market size based on company estimates and American Society of Plastic Surgeons annual statics report (2019) 5#6COMPREHENSIVE BREAST PRODUCT PORTFOLIO Tissue Expanders AlloX2Ⓡ Only expander with patented direct access to the periprosthetic space¹ TM Dermaspan ™ Designed for comfort and expansion Gel Implants • Engineered with a strong but soft design to resist rupture and gel fracture² . First and only complete 5th generation cohesive gel breast implants • >250 round and >90 teardrop shaped implant options Robust 10-year clinical results³ • Leading 20-year warranty program round teardrop shape gel implants Scar Treatment FDA-cleared patented crosslinked silicone technology4 BOCORNELM BIOCORNEUMⓇ sientra. gel implants 1 U.S. Patent No. 8,454,890. 2 Kinney BM, Jeffers LLC, Ratliff GE, Carlisle DA. Silicone gel breast implants: science and testing. Plast Reconstr Surg. 2014;134(1S):47S-56S. 3 Calobrace MB, Schwartz MR, Zeidler KR, Pittman TA, Cohen R, Stevens WG. Long-term safety of textured and smooth breast implants. Aesth Surg. 2017;1-11.(4S):7S-19S. 4 U.S. Patent Nos. 5,741,509; 8,021,683; # 8,802,133; 9,336,546; 9,795,706 6#7Gel Implants IMPLANT DESIGN FEATURES & CHOICE Designed to Hold Their Shape Balance of Strength and Softness¹ A Choice of Smooth and Microtextured Surface Options EXCLUSIVE HIGH STRENGTH COHESIVE GEL HIGHEST LEVEL OF GEL- SHELL INTEGRATION' SHALLOW PATHWAYS FLAT BACK DESIGN GEL FILL LEVEL SMOOTH CONTOUR EDGES ROUND, SHAPED PORES sientra. 1 Kinney BM, Jeffers LLC, Ratliff GE, Carlisle DA. Silicone gel breast implants: science and testing. Plast Reconstr Surg. 2014;134(1S):47S-56S; Sientra GRADUAL PEAKS AND VALLEYS Allergan BIOCELL® Rough, sharp cubic structures with deep pathways 7#8Gel Implants COMPELLING 10-YEAR CLINICAL VALIDATION¹ The largest breast implant study of its kind Complication Primary Augmentation Complication Rates 1,2 Mentor 10-Yr (N=552) Allergan 10-Yr (N=455) Sientra 10-Tr (N=1,116) Number of Implants 2,230 1,102 908 MRI Cohort Patients 398 220 158 Rupture (MRI cohort) 8.7% 24.2% 9.3% Reoperation 24.2% 25.5% 36.1% Capsular Contracture III/IV 12.9% 12.1% 18.9% Low Low Rupture Rate 2,3 Low Capsular Contracture Rate 2,3 Reoperation Rate 2,3 FOR INFORMATIONAL PURPOSES ONLY - differences exist between trial designs and subject populations. No head-to-head study has been conducted comparing Sientra's breast products to these products. 1 Stevens WG, Calobrace MB, Alizadeh A, Zeidler KR, Harrington JL, d'Incelli RC. Ten-year core study data for Sientra's Food and Drug Administration - approved round and shaped breast implants with cohesive silicone gel. Plast Reconstr Surg. 2018;141(4S):7S-19S; 2 Calobrace MB, Schwartz MR, Zeidler KR, Pittman TA, Cohen R, Stevens WG. Long-term safety of textured and sientra, smooth breast implants. Aesth Surg. 2017;1-11.(4S): 7S-19S: 3 primary augmentation cohort 8#9Gel Implants COMMITMENT TO SAFETY LEADING 20-YEAR WARRANTY & SURGEON EXLUSIVITY LIFETIME Guarantee 20-Year Guarantee ✓ FREE implant replacement for implant rupture ✓ Up to $5,000 for uncovered fees and costs due to implant rupture and $7,500 for uncovered fees and costs due to BIA-ALCL FREE implant replacement for complications of capsular contracture, (Baker Grade III/IV), late forming seroma¹, double capsule and BIA-ALCL 2-Year Pledge ✓ Up to $2,000 for uncovered fees and costs due to capsular contracture (Baker Grade III/IV), late forming seroma¹ and double capsule LATINUM20 SIENTRA. A TM YEAR Surgeon Exclusivity The only silicone gel implant available exclusively to board-certified and board-eligible plastic surgeons We believe high-performing implants exclusively in the hands of the most skilled and qualified surgeons lead to safer and more natural outcomes 1 For qualifying patients with late forming seroma, Sientra will cover the cost of complete testing, based on current best practices, for Breast Implant Associated-Anaplastic Large Cell sientra. Lymphoma (BIA-ALCL). 9#10Tissue Expanders INNOVATIVE BREAST TISSUE EXPANDERS Allo X2Ⓡ ONE of a kind aspiration port expansion port Integral drain Dual-port design and integral drain: Provide direct access to the periprosthetic space Enable fluid aspiration and allow for less invasive, non-surgical draining of serious fluid ✓ Mitigate risks associated with breast expansion and ultimately reduce reoperation rates Allow for diagnostic fluid sampling Soft, refined design allows for gentle and more comfortable expansion ✓Soft, pliable outer shell reduces friction upon insertion Without ridges or rings for improved comfort Port location designed to aid in predictable, consistent expansion Dermaspan ™ ONE for all sientra. 10#11Tissue Expanders ALLOX2 SUPPORTING HEALTH AND ECONOMIC OUTCOMES A seroma increases the risk of major infection in breast reconstruction patients • Clinically relevant infection in poor salvage rates occurred in 1/5 seroma patients (18.8%) 1 • • With current standard of care, 78% of infections require explantation¹ Re-operation costs can run upwards of +$20K² ADM (ACELLULAR DERMAL MATRIX) $6-12,000 per breast* BREAST TISSUE EXPANDER > $1,300 - 2,300 per breast OR/ANESTHESIA COSTS $17,500 2 hr procedure and 1-2 nights ICU stay** TOTAL ESTIMATED REOPERATION COST $25 - $32K Unilateral $32 - $46K Bilateral Allox2 clinically shown to improve expander salvage rates and clinical outcome³ 100% Surgeon Satisfaction Using Allox24 BREAST Sientra AlloX2 Short-Term Case Study, Surgical Pearls, and Roundtable Discussion In a clinical study with 40 primary reconstruction patients, the Allox2 was deemed successful in treating seromas and should be considered a tool for noninvasive treatment of common complications of tissue expander-based reconstruction sientra. 1 Jordan SW, Khavanin N, Kim JYS. Seroma in prosthetic breast reconstruction. Plast Reconstr Surg. 2016;137:1104-1116; 2 Macario A. What does one minute of operating room time cost? Journal of Clinical Anesthesia. 2010;22, 233-236; 3 Fairchild B, Ellsworth W, Selber JC, Bogue DP, Zavlin D, Nemir S, Checka CM, Clemens MW. Safety and Efficacy of Smooth Surface Tissue Expander Breast Reconstruction. Aesth Surg. Volume 40, Issue 1, January 2020, Pages 53-62, https://doi.org/10.1093/asi/siy 199.4 Zeidler K, Capizzi P, Pittman T. (2018). Sientra AlloX2 Short Term Case Study, Surgical Pearls & Roundtable Discussion. Manuscript submitted for publication. 11#12WHY CUSTOMERS CHOOSE SIENTRA Safety Compelling safety and clinical validation Selection Varied sizes, textures and shapes allow surgeons to meet patient preferences Security The industry's most comprehensive warranty Surgeons Focused exclusively on board-certified and board- eligible plastic surgeons Service Tailored to a practice's success with marketing programs, industry education and a concierge, always-on approach Supply Chain Proudly manufactured and sourced in the U.S. sientra. 12#13NEW SIENTRA CAMPAIGN PROMOTES THE EVOLUTION OF DECISION MAKING "See Yourself in Sientra" Campaign sientra see yourself in THE EAST IMPLANTS WITH AN unrivaled safety profile see safety sor security ser exclusivity sientra see yourself an sientra BREAST RECONSTRUCTION sientra • . see yourself in sientra Actual Sientra Patients Survey suggests today's consumer wants to be informed of their brand choices with safety and support are the top drivers¹ • Patients: 80% surveyed likely to ask for Sientra by name once informed on competitive differentiation Surgeons: 71% would add a new brand if more patients ask and 55% would switch manufacturers if more patients ask Digital marketing efforts focused on unique product benefits & unrivaled safety profile backed by industry leading Platinum 20™ Warranty sientra. 1 Based on survey of consumers (n=215) and plastic surgeons (n=109), July 2020 13#14$ Millions STRONG BREAST PRODUCTS GROWTH CADENCE CONTINUED IN Q1 $25 $20 $15 $10 $5 19% 47% Impact of Covid-19 28% 22% $12.6 $12.8 $12.5 $11.2 -17% $9.3 47% 40% 21% $18.3 $17.9 $15.3 $0 Q2'19 Q3'19 Q4'19 Q1'20 Q2'20 Q3'20 Q4'20 Q1'21 Breast Products -YoY Growth sientra. 1. Includes Japan sales starting in Q3 2020. 2020 Japan sales totaled $1.7M • • 1Q21 Growth Drivers Continued share gains within accounts Outperformance of overall augmentation market • 200+ new account openings - total active accounts to 2,400 14#15FY 2020 SALES SUMMARY Consolidated Net Sales Net Sales ($ in millions) $83.7 Breast Products Segment Net Sales & Y/Y Growth Net Sales/ Growth ($ in millions) $55.0 $46.4 $71.2 $68.1 $17.9 $37.0 +40% +22% $12.8 $46.4 $10.4 +28% $37.0 $12.6 +47% $15.3 +21% $55.0 $8.6 +13% $11.2 +19% $9.3 -17% $9.4 +15% $37.3 $31.1 $16.2 2018 2019 2020 ■MiraDry Breast Products $8.5 +14% $9.8 $12.5 +28% +14% 2018 2019 2020 Q1 Q2 Q3 Q4 Shift in investment to Breast Products from miraDry in 2Q20 reflected in miraDry net sales decline FY2020 Momentum continued into 2021 Cash balance of $80.4M as of March 31, 2021 Including Net Proceeds of ~$39.2M from February 2021 Public Offering sientra. 15#162021 FINANCIAL GUIDANCE Sales ● Breast Products net sales of $72 - $76 million, representing 31 - 38% y/y growth Operating Expenses • FY 2021 OpEx expected to be in the range of $85 - $90 million(1) sientra. 1 Excluding impairment and restructuring charges 16#17see yourself again in sientra. sientra. 17