June 2017

2 Confidential: contains proprietary information

Forward-looking Statements & Disclaimer 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 that are based on management's current assumptions and expectations of future events and trends and involve risks and uncertainties. Forward-looking statements include, but are not limited to, statements regarding Sientra's ability to successfully commercialize its products, market acceptance of its products, the planned acquisition of Miramar Labs, Inc. which is the subject of this presentation and the success thereof, market opportunities and ability to achieve expected growth, sales and financial results, the Company’s continued efforts to secure a stable manufacturing supply chain that ensures uninterrupted access to its breast implant products, and the experience of tis aesthetics sales force are subject to risks and uncertainties. The Company's business, strategy, operations or financial performance, and actual results may differ materially from those predicted or implied and reported results should not be considered as an indication of our future performance. There can be no assurance that the acquisition of Polytech will be completed as currently contemplated, or at all. In addition, there can be no assurance that intended benefits of the acquisition, including any projected pro forma operating results, will be realized on the timetable currently estimated, or at all. 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.

This presentation includes estimated projections of future operating results. These projections were not prepared in accordance with published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants or the Public Company Accounting Oversight Board for preparation and presentation of financial projections. This information is not fact and should not be relied upon as being necessarily indicative of future results; the projections were prepared in good faith by management and are based on numerous assumptions that may prove to be wrong. Important factors that may affect actual results and cause the projections to not be achieved include, but are not limited to, risks and uncertainties relating to the company and other factors described under “Risk Factors” sections of the Company’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q or Current Reports on Form 8-K and “Forward-Looking Statements.” The projections also reflect assumptions as to certain business decisions that are subject to change. As a result, actual results may differ materially from those contained in the estimates. Accordingly, there can be no assurance that the estimates will be realized.

Management is using non-GAAP financial measures in this presentation because it considers them to be important supplemental measures of the Company’s performance. Non-GAAP financial measures should be considered in addition to, not as a substitute for, net income, total debt or other financial measures prepared in accordance with GAAP. The Company’s methods of determining these non-GAAP financial measures may differ from the methods used by other companies for these or similar non-GAAP financial measures. Accordingly, these non-GAAP financial measures may not be comparable to measures used by other companies.

This presentation also contains estimates and other statistical data made by independent parties and by the Company relating to market size and growth and other industry data. This presentation also contains estimates and information from the management of Polytech relating to market position and financial data. These data involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. The Company has not independently verified the statistical and other industry data generated by independent parties and contained in this presentation and, accordingly, it cannot guarantee their accuracy or completeness. In addition, projections, assumptions and estimates of its future performance and the future performance of the industries in which it operates are necessarily subject to a high degree of uncertainty and risk due to a variety of factors. In addition, the industry in which we operate is subject to a high degree of uncertainty and risk due to variety of factors, including those described in the “Risk Factors” section of the Company’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q or Current Reports on Form 8-K. These and other factors could cause results to differ materially from those expressed in the estimates made by the independent parties and by Sientra. Undue reliance should not be placed on the forward-looking statements in this release, which are based on information available to the Company on the date hereof, and except to the extent required by law, Sientra assumes no obligation to update such statements.

3 Confidential: contains proprietary information

Sientra is a high quality platform poised for broader expansion in the aesthetic market ▫ Industry leading plastic surgeon relationships

▫ Best in class aesthetic sales force

▫ Clear path to high quality supply chain & re-entry to breast implant market

▫ Innovative technology & differentiated products

▫ Transitioning to growth w/ adjacent products & diversifying product portfolio

▫ Recently acquired miraDry, the only FDA cleared product to reduce sweat, odor and permanently reduce hair of all color

▫ Strong balance sheet

▫ Building a global aesthetics company

4 Confidential: contains proprietary information

Sientra team

86 employees corporate: 41 sales: 45

leadership team

138+ years of aesthetics experience

JEFFREY NUGENT Chairman & CEO

Joann Kuhne VP, Reg Affairs & QA

Dan Carlisle VP, Prod. Tech & Mfg.

Rich Low VP, Marketing

Rosalyn d’Incelli VP, Clinical Operations & Medical Affairs

Jason O’Hearn VP, Sales

Charlie Huiner Chief Operating Officer & SVP Corporate Development & Strategy

Deborah Bettencourt VP, Cust. Exp. & Corp. Admin.

Patrick F. Williams Chief Financial Officer, SVP & Treasurer

5 Confidential: contains proprietary information

$12.1 $12.4

$14.2 $12.9

$1.5 $1.5

$6.2 $6.2 $6.5 $7.5

$0.00

$2.00

$4.00

$6.00

$8.00

$10.00

$12.00

$14.00

$16.00

$18.00

$20.00

Q4 14 Q1 15 Q2 15 Q3 15 Q4 15 Q1 16 Q2 16 Q3 16 Q4 16 Q1 17

Revenue ($M's)

Historical Revenue

▫ Successful IPO in Q3’14 ▫ Voluntary hold on sales beginning Q4 ‘15 ▫ Controlled commercial relaunch Q1’16

Voluntary Hold

Controlled Re-Launch

6 Confidential: contains proprietary information

▫ Services agreement with Vesta, a Berkshire Hathaway company, announced August 2016

▫ Vesta provides six-sigma quality manufacturing & product development control

▫ Solely Sientra-focused, no indicated capacity constraints

▫ On track to meet uninterrupted manufacturing supply for U.S. customers

*Vesta is a subsidiary of The Lubrizol Corporation.

Vesta: A Reputable Manufacturing Partner

product/process

development

submit regulatory

package

validation/testing

estimated

FDA approval

Q2 2016

Q1 2017

Q2 2017

Q4 2017 Key Vesta Milestones

7 Confidential: contains proprietary information

Building a Foundation for Robust Growth

U.S. market re-entry following voluntary hold

Validated industry leading safety profile

Acquired bioCorneum+

Entered MFG services agreement with Vesta

Submit PMA supplement for Vesta MFG site

Initial re-supply by Vesta

return to high growth sales

model

Jan 2016

Mar 2016

Mar 2016

Aug 2016

$57M historical peak revenue

run rate* Acquired SSP breast tissue expanders

Nov 2016

Mar 2017

Q4 2017

*Annualized 2Q15 revenue

Acquiring Miramar Labs

Jun 2017

8 Confidential: contains proprietary information

Market Context

Market in $ millions

Current Market

Size

SIEN Sales (@ peak run rate)

SIEN Peak

Market Share

Cosmetic Breast – U.S. [$400 - $40*] = $360 $47 13%

Scar Management $30 $4 13%

Recon Breast – U.S. $120 $5 4%

Tissue Expanders – U.S. $160 $4 2%

PS Regen Recon - U.S. (ADM + Fat

Grafting) $370 $0 0%

Canada Breast Aesthetics $40 $0 0%

OUS/OCAN Breast Aesthetics $400 $0 0%

Global Surgical Aesthetics: $1,500 $60 4%

Sientra has been primarily a US cosmetic breast aesthetics business: elective,

cash-pay, private practice and solely board certified plastic surgeons

* Note, Cosmetic Breast Market Size excludes $40 million sales to non-board certified

plastic surgeons that Sientra does not support.

9 Confidential: contains proprietary information

Business Development

Precision Launch Strategy to Maintain Core Business

Re-establish trust & confidence Publish testing results Re-engage KOLs

Maintain premium pricing Focus on top-tier customers Avoid backorder risk

Enhance customer service Additional practice contributions Expand product offering

Maximize Inventory

Product Messaging

10 Confidential: contains proprietary information

Acquired in June 2017 for $20M cash and up to $14M in milestones − Highly profitable for physician practice and

affordable for patients

− No significant competition

Miramar Labs, Inc. Acquisition

− Global commercial footprint with 900 systems sold and over 90,000 procedures completed

miraDry: ONLY non-invasive

treatment FDA cleared for

reduction of underarm:

Hair of all colors

Odor

Sweat

− 2016 revenue of ~$20M, up 19% YoY +20% CAGR (2013-2016)

− Strong clinical data with over 10 clinical studies, 5 white papers & 7 peer reviewed papers

June 2017

11 Confidential: contains proprietary information

Becoming a Global Diversified Aesthetics Company

1. Novel technology – Only FDA approved product to reduce sweat, odor and hair of all color

– Highly efficacious with compelling clinical results and ~90% patient satisfaction

– Highly regarded by Key Opinion Leaders across all aesthetic specialties

2. Meaningfully expands Total Addressable Market – Fast growing aesthetic segment

– Addressable market of over 15 million patients in the US

– Expands global distribution platform

– Cross selling opportunities through both sales force account intros

– Adds new physician specialty call points

3. Immediately revenue accretive at attractive valuation – Meaningfully accretive to full year 2018 revenues

– Achieve positive cash flow faster as a combined company

– High margin consumables >40% of revenue

Sientra to Acquire (announced June 12th)

12

Sientra U.S. Breast Business Mix

Vision for the New Sientra – a Broad Aesthetics Play

Operating Room Focus Procedure Room Focus

33 Plastic Surgery Consultants

5 Multi Specialty Consultants

7 Capital Sales Reps

9 Practice Development Managers

30%

40%

30%

100% Plastics

Derms

Other Board

Certified

Plastics

Miramar U.S. Business Mix

13 1. Doolittle J, Walker P, Mills T, Thurston J. Hyperhidrosis: an update on prevalence and severity in the United States. Arch Dermatol Res. 2016;308:743-749..

Significant Market Opportunity1

▫ The market for sweat

controlling products is large

and highly underpenetrated

▫ ~5M patients in the U.S. with

axillary sweating are not at all

satisfied or only slightly

satisfied with current products

15M Seeking sweat

control options

10M Axillary (underarm)

5M Severe

sweating

14

Proven Sales & Execution Playbook

Revised marketing in Int’l markets

Initiate potential bundling opportunities

Expand US consumable sales team

Execute proven marketing playbook

SFDC - predictability of capital pipeline

Expand US capital sales team

Cross selling opportunities for Sientra/Miramar 1

2

3

4

5

6

7

15

Opportunity to Improve Execution with

Disciplined Commercial Approach

Execution Improvement Opportunities

Enhance Treatment Protocol

PDM and rep training

Physician and staff training

miraDry University

Deploy Marketing Tactics Build brand awareness

Co-op advertising

Digital/social media

Optimized Sales Force Efforts

Increase clinical and sales training

Ensure outstanding clinical outcomes

Increase investment in sales & marketing

16

Deal Structure and Financing ▫ Tender offer and second step merger

▫ Sientra to acquire all of the outstanding shares of Miramar’s common stock for $20M in up front cash plus the contractual right to receive contingent payments of up to $14M in cash as follows:

– $20 million cash upon closing

– $7 million cash upon $50 million in cumulative sales

– $7 million cash upon $80 million in cumulative sales

– Anticipate ~$2.5M in deal expenses

– Expected mid-July close

▫ Cash and cash equivalents of $58.8M as of 3/31/2017

– Approximately $57M as of 5/31/17

▫ Securing $50M credit facility accessible in tranches

– Closing - $25M

– PMA Supplement Approval - $10M

– $75M cumulative revenue - $5M

– Revolver of $10M replaces existing $15M revolver

17

Financial Expectations

Revenue Accretion Expectations

▫ Expect $8M - $10M in revenue for 2H17

▫ Meaningfully accretive to total revenue growth in 2018

– Cross selling through sales force account intros

– Deploy proven marketing playbook

– Achieve positive cash flow faster as a combined company

– High margin consumables >40% of revenue

Cost Synergy Expectations

▫ Modest public company cost synergies in 2018

▫ Allows Sientra to achieve cash flow breakeven faster than as a standalone company

– Larger revenue base

– High margin consumables

18 Confidential: contains proprietary information

Driving Multi-faceted Growth

Scale manufacturing to support deeper account penetration

Leverage high quality sales force within board certified plastic surgeon community

Leverage strong balance sheet position to execute revenue accretive deals

OR

GA

NIC

IN

OR

GA

NIC

Disciplined M&A in plastic surgery and other aesthetic adjacencies

Add complementary products to portfolio

19 Confidential: contains proprietary information

Building a global aesthetics company

Why own Sientra today?

Innovative technology & differentiated products

Clear path to high quality supply chain & re-entry to breast implant market

Transitioning to growth w/ adjacent products & diversifying product portfolio

New player in profitable and growing aesthetic capital/consumable market

THANK YOU