Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	a. Basis of Presentation The accompanying unaudited condensed consolidated financial statements of Sientra, Inc. (“Sientra”, the “Company”, “we”, “our”, or “us”) in this Quarterly Report on Form 10-Q have been prepared in accordance with U.S. generally accepted accounting principles, or "GAAP", and the rules and regulations of the U.S. Securities and Exchange Commission, or the "SEC". Accordingly, they do not include certain notes and financial presentations normally required under GAAP for complete financial reporting. The interim financial information is unaudited, but reflects all normal adjustments and accruals which are, in the opinion of management, considered necessary to provide a fair presentation for the interim periods presented. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on April 18, 2023, or the Annual Report. The results for the three and six months ended June 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period. Reverse Stock Split On January 19, 2023, the Company effected a 1-for-10 reverse stock split (the “Reverse Stock Split”) of the Company’s issued and outstanding common stock, par value $0.01 per share (the “Common Stock”) by the filing of a Certificate of Amendment (the “Certificate”) with the Secretary of State of the State of Delaware pursuant to the Delaware General Corporation Law. The Reverse Stock Split became effective on January 19, 2023. As a result of the Reverse Stock Split, every 10 shares of Common Stock issued and outstanding were automatically reclassified into one new share of common stock. The Reverse Stock Split did not modify any rights or preferences of the shares of Common Stock. Proportionate adjustments were made to the exercise or conversion prices and the number of shares underlying the Company’s outstanding equity awards, convertible securities and warrants, as well as to the number of shares issued and issuable under the Company’s equity incentive plans. The Common Stock issued pursuant to the Reverse Stock Split remained fully paid and non-assessable. The Reverse Stock Split did not affect the number of authorized shares of Common Stock or the par value of the Common Stock. All share information in the accompanying financial statements has been adjusted to reflect the results of the Reverse Stock Split. Discontinued Operations of miraDry As a result of the miraDry sale discussed in Note 2, the miraDry business met the criteria to be reported as discontinued operations. Therefore, the Company is reporting the historical results of miraDry, including the results of operations, cash flows, and related assets and liabilities, as discontinued operations for all periods presented herein through the date of the Sale. Unless otherwise noted, the accompanying notes to the unaudited condensed consolidated financial statements have all been revised to reflect continuing operations only. Following the sale the Company has one operating segment in continuing operations named Plastic Surgery, formerly known as Breast Products.
Liquidity and Going Concern	b. Liquidity and Going Concern The accompanying unaudited condensed consolidated financial statements of the Company have been prepared assuming the Company will continue as a going concern and in accordance with GAAP. The going concern basis of presentation assumes that the Company will continue in operation one year after the date these financial statements are issued and will be able to realize its assets and discharge its liabilities and commitments in the normal course of business. Pursuant to the requirements of the Financial Accounting Standards Board’s Accounting Standards Codification (“ASC”) Topic 205-40, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, management must evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern for one year from the date these condensed consolidated financial statements are issued. This evaluation does not take into consideration the potential mitigating effect of management’s plans that have not been fully implemented or are not within control of the Company as of the date the condensed consolidated financial statements are issued. When substantial doubt exists under this methodology, management evaluates whether the mitigating effect of its plans sufficiently alleviates substantial doubt about the Company’s ability to continue as a going concern. The mitigating effect of management’s plans, however, is only considered if both (1) it is probable that the plans will be effectively implemented within one year after the date that the financial statements are issued, and (2) it is probable that the plans, when implemented, will mitigate the relevant conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. Since the Company’s inception, it has incurred recurring losses and cash outflows from operations and the Company anticipates that losses will continue in the near term. During the six months ended June 30, 2023, the Company incurred net losses of $22.4 million and used $7.4 million of cash from continuing operations. As of June 30, 2023, the Company had cash and cash equivalents of $18.6 million. As a result of these conditions substantial doubt exists about our ability to continue as a going concern for a period of at least one year from the date of issuance of these unaudited condensed consolidated financial statements. The unaudited condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of liabilities that might be necessary should the Company be unable to continue as a going concern. In an effort to alleviate these conditions, management is currently evaluating various cost-saving measures in order to reduce operating expenses and cash outflows. However, the Company will need to generate a significant increase in net sales to further improve profitability and cash inflows, which is dependent upon continued growth in our Plastic Surgery segment and the launch of new products and partnerships. Additionally, we are evaluating various funding alternatives to improve liquidity and may seek to raise additional equity or debt capital, refinance our debt obligations or obtain waivers, and/or scale back or freeze our organic growth plans to manage our liquidity and capital resources. As the Company seeks additional sources of financing, there can be no assurance that such financing would be available to the Company on favorable terms or at all. The Company’s ability to obtain additional financing in the equity capital markets is subject to several factors, including market and economic conditions, the Company’s performance and investor sentiment with respect to the Company and its industry. During 2022, to fund ongoing operating and capital needs, the Company raised additional capital through the sale of equity securities and incremental debt financing. See Note 7 to the condensed consolidated financial statements for further details.
Recent Accounting Pronouncements	c. Recent Accounting Pronouncements Recently Adopted Accounting Standards In August 2020, the FASB issued ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity. The amendment eliminates certain accounting models and simplifies the accounting for convertible instruments and enhances disclosures for convertible instruments and earnings per share. The amendments are effective for public entities excluding smaller reporting companies for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023 including interim periods within those fiscal years and early adoption is permitted. The Company adopted this guidance effective January 1, 2023 under the modified retrospective adoption approach and there was no material impact on its consolidated financial statements from the adoption. Recently Issued Accounting Standards In December 2022, the FASB issued ASU 2022-06, Deferral of the Sunset Date of Topic 848 that extends the period of time preparers can utilize the reference rate reform relief guidance. In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. To ensure the relief in Topic 848 covers the period of time during which a significant number of modifications may take place, the ASU defers the sunset date of Topic 848 from December 31, 2022, to December 31, 2024, after which entities will no longer be permitted to apply the relief in Topic 848. The Company is currently evaluating the impact the election of the optional expedient will have on the consolidated financial statements.
Risks and Uncertainties	d. Risks and Uncertainties The COVID-19 pandemic and its related macroeconomic effects significantly impacted our business and results of operations in past years. At the height of the pandemic and as an aesthetics company, the surgical procedures involving our breast products were susceptible to local and national government restrictions. The inability or limited ability to perform non-emergency procedures significantly harmed our revenues starting in the second quarter of 2020 and lasting through the first quarter of 2022. While restrictions on non-emergency procedures have been removed, there is still substantial uncertainty as to when, if at all, the aesthetic procedures that the Company’s products are sold into will return to pre-pandemic levels. In addition, the global economy, including the financial and credit markets, has recently experienced extreme volatility and disruptions, including increases to inflation rates, rising interest rates, declines in consumer confidence, declines in economic growth, and uncertainty about economic stability. The severity and duration of the impact of these conditions on our business cannot be predicted. The estimates used for, but not limited to, determining the collectability of accounts receivable, fair value of long-lived assets and goodwill, and sales returns liability required could be impacted by the factors described above. While the full impact and duration of the factors noted above is unknown at this time, the Company has made appropriate estimates based on the facts and circumstances available as of the reporting date. These estimates may change as new events occur and additional information is obtained.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2023

The accompanying unaudited condensed consolidated financial statements of Sientra, Inc. (“Sientra”, the “Company”, “we”, “our”, or “us”) in this Quarterly Report on Form 10-Q have been prepared in accordance with U.S. generally accepted accounting principles, or "GAAP", and the rules and regulations of the U.S. Securities and Exchange Commission, or the "SEC". Accordingly, they do not include certain notes and financial presentations normally required under GAAP for complete financial reporting. The interim financial information is unaudited, but reflects all normal adjustments and accruals which are, in the opinion of management, considered necessary to provide a fair presentation for the interim periods presented. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on April 18, 2023, or the Annual Report. The results for the three and six months ended June 30, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period.

Reverse Stock Split

On January 19, 2023, the Company effected a 1-for-10 reverse stock split (the “Reverse Stock Split”) of the Company’s issued and outstanding common stock, par value $0.01 per share (the “Common Stock”) by the filing of a Certificate of Amendment (the “Certificate”) with the Secretary of State of the State of Delaware pursuant to the Delaware General Corporation Law. The Reverse Stock Split became effective on January 19, 2023.

As a result of the Reverse Stock Split, every 10 shares of Common Stock issued and outstanding were automatically reclassified into one new share of common stock. The Reverse Stock Split did not modify any rights or preferences of the shares of Common Stock. Proportionate adjustments were made to the exercise or conversion prices and the number of shares underlying the Company’s outstanding equity awards, convertible securities and warrants, as well as to the number of shares issued and issuable under the Company’s equity incentive plans. The Common Stock issued pursuant to the Reverse Stock Split remained fully paid and non-assessable. The Reverse Stock Split did not affect the number of authorized shares of Common Stock or the par value of the Common Stock. All share information in the accompanying financial statements has been adjusted to reflect the results of the Reverse Stock Split.

Discontinued Operations of miraDry

As a result of the miraDry sale discussed in Note 2, the miraDry business met the criteria to be reported as discontinued operations. Therefore, the Company is reporting the historical results of miraDry, including the results of operations, cash flows, and related assets and liabilities, as discontinued operations for all periods presented herein through the date of the Sale. Unless otherwise noted, the accompanying notes to the unaudited condensed consolidated financial statements have all been revised to reflect continuing operations only. Following the sale the Company has one operating segment in continuing operations named Plastic Surgery, formerly known as Breast Products.

Liquidity and Going Concern

The accompanying unaudited condensed consolidated financial statements of the Company have been prepared assuming the Company will continue as a going concern and in accordance with GAAP. The going concern basis of presentation assumes that the Company will continue in operation one year after the date these financial statements are issued and will be able to realize its assets and discharge its liabilities and commitments in the normal course of business.

Pursuant to the requirements of the Financial Accounting Standards Board’s Accounting Standards Codification (“ASC”) Topic 205-40, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, management must evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern for one year from the date these condensed consolidated financial statements are issued. This evaluation does not take into consideration the potential mitigating effect of management’s plans that have not been fully implemented or are not within control of the Company as of the date the condensed consolidated financial statements are issued. When substantial doubt exists under this methodology, management evaluates whether the mitigating effect of its plans sufficiently alleviates substantial doubt about the Company’s ability to continue as a going concern. The mitigating effect of management’s plans, however, is only considered if both (1) it is probable that the plans will be effectively implemented within one year after the date that the financial statements are issued, and (2) it is probable that the plans, when implemented, will mitigate the relevant conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued.

Since the Company’s inception, it has incurred recurring losses and cash outflows from operations and the Company anticipates that losses will continue in the near term. During the six months ended June 30, 2023, the Company incurred net losses of $22.4 million and used $7.4 million of cash from continuing operations. As of June 30, 2023, the Company had cash and cash equivalents of $18.6 million. As a result of these conditions substantial doubt exists about our ability to continue as a going concern for a period of at least one year from the date of issuance of these unaudited condensed consolidated financial statements. The unaudited condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of liabilities that might be necessary should the Company be unable to continue as a going concern.

In an effort to alleviate these conditions, management is currently evaluating various cost-saving measures in order to reduce operating expenses and cash outflows. However, the Company will need to generate a significant increase in net sales to further improve profitability and cash inflows, which is dependent upon continued growth in our Plastic Surgery segment and the launch of new products and partnerships. Additionally, we are evaluating various funding alternatives to improve liquidity and may seek to raise additional equity or debt capital, refinance our debt obligations or obtain waivers, and/or scale back or freeze our organic growth plans to manage our liquidity and capital resources. As the Company seeks additional sources of financing, there can be no assurance that such financing would be available to the Company on favorable terms or at all. The Company’s ability to obtain additional financing in the equity capital markets is subject to several factors, including market and economic conditions, the Company’s performance and investor sentiment with respect to the Company and its industry.

During 2022, to fund ongoing operating and capital needs, the Company raised additional capital through the sale of equity securities and incremental debt financing. See Note 7 to the condensed consolidated financial statements for further details.

Recent Accounting Pronouncements

Recently Adopted Accounting Standards

In August 2020, the FASB issued ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity. The amendment eliminates certain accounting models and simplifies the accounting for convertible instruments and enhances disclosures for convertible instruments and earnings per share. The amendments are effective for public entities excluding smaller reporting companies for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023 including interim periods within those fiscal years and early adoption is permitted. The Company adopted this guidance effective January 1, 2023 under the modified retrospective adoption approach and there was no material impact on its consolidated financial statements from the adoption.

Recently Issued Accounting Standards

In December 2022, the FASB issued ASU 2022-06, Deferral of the Sunset Date of Topic 848 that extends the period of time preparers can utilize the reference rate reform relief guidance. In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. To ensure the relief in Topic 848 covers the period of time during which a significant number of modifications may take place, the ASU defers the sunset date of Topic 848 from December 31, 2022, to December 31, 2024, after which entities will no longer be permitted to apply the relief in Topic 848. The Company is currently evaluating the impact the election of the optional expedient will have on the consolidated financial statements.

Risks and Uncertainties

The COVID-19 pandemic and its related macroeconomic effects significantly impacted our business and results of operations in past years. At the height of the pandemic and as an aesthetics company, the surgical procedures involving our breast products were susceptible to local and national government restrictions. The inability or limited ability to perform non-emergency procedures significantly harmed our revenues starting in the second quarter of 2020 and lasting through the first quarter of 2022. While restrictions on non-emergency procedures have been removed, there is still substantial uncertainty as to when, if at all, the aesthetic procedures that the Company’s products are sold into will return to pre-pandemic levels.

In addition, the global economy, including the financial and credit markets, has recently experienced extreme volatility and disruptions, including increases to inflation rates, rising interest rates, declines in consumer confidence, declines in economic growth, and uncertainty about economic stability. The severity and duration of the impact of these conditions on our business cannot be predicted.

The estimates used for, but not limited to, determining the collectability of accounts receivable, fair value of long-lived assets and goodwill, and sales returns liability required could be impacted by the factors described above. While the full impact and duration of the factors noted above is unknown at this time, the Company has made appropriate estimates based on the facts and circumstances available as of the reporting date. These estimates may change as new events occur and additional information is obtained.