Organization and Basis of Presentation	6 Months Ended
Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation The Company Zosano Pharma Corporation (the “Company”) is a clinical stage biopharmaceutical company focused on providing rapid systemic administration of therapeutics to patients using its proprietary Adhesive Dermally-Applied Microarray, or ADAM™, technology. Basis of Presentation The condensed financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) for interim financial information, the instructions to Form 10-Q and Regulation S-X. They do not include all the information and notes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019, or any other subsequent period. These financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2018, included in the Company’s annual report on Form 10-K and filed with the United States Securities and Exchange Commission (“SEC”) on March 25, 2019. Use of Estimates The preparation of the accompanying condensed financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the condensed financial statements, and the reported amounts of expenses during the periods reported. Actual results could differ from those estimates. Liquidity and Substantial Doubt in Going Concern Since inception, the Company has incurred recurring operating losses and negative cash flows from operating activities, and as of June 30, 2019, had an accumulated deficit of $280.0 million. As of June 30, 2019, the Company had approximately $17.7 million in cash, cash equivalents and marketable securities. Presently, the Company does not have sufficient cash, cash equivalents and marketable securities to enable it to fund its anticipated level of operations and meet its obligations as they become due within twelve months following the date of issuance of this Quarterly Report on Form 10-Q. The aforementioned factors raise substantial doubt about the Company’s ability to continue as a going concern for a period of one year from the issuance of these financial statements. The financial statements do not include any adjustments that might result from the outcome of this uncertainty. On April 11, 2019, the Company closed a public offering of 5,000,000 shares of common stock at a price to the underwriter of $3.29 per share. On May 8, 2019, the underwriter purchased an additional 750,000 shares at a price to the underwriter of $3.29 per share pursuant to the exercise of the underwriter's option to purchase additional shares. The aggregate net proceeds were approximately $18.3 million, after deducting underwriting costs and estimated offering expenses. The Company plans to raise additional funding through financing, a capital offering, a license or collaboration agreement or a combination of such sources of capital. However, there are no assurances that additional funding will be achieved and that the Company will succeed in its future operations. The Company’s inability to obtain required funding in the near future or its inability to obtain funding on favorable terms will have a material adverse effect on its operations and strategic development plan for future growth. If the Company cannot successfully raise additional capital and implement its strategic development plan, its liquidity, financial condition and business prospects will be materially and adversely affected, and it may have to cease operations. The Company will continue to evaluate its timelines, strategic needs, and working capital requirements. There can be no assurance that if the Company attempts to raise additional capital, it will be successful in doing so on terms acceptable to the Company, or at all. Further, there can be no assurance that it will be able to gain access and/or be able to execute on securing new sources of funding, new development opportunities, successfully obtain regulatory approvals for and commercialize new products, achieve significant product revenues from its products (if approved), or achieve or sustain profitability in the future.

Organization and Basis of Presentation

The Company

Zosano Pharma Corporation (the “Company”) is a clinical stage biopharmaceutical company focused on providing rapid systemic administration of therapeutics to patients using its proprietary Adhesive Dermally-Applied Microarray, or ADAM™, technology.

Basis of Presentation

The condensed financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) for interim financial information, the instructions to Form 10-Q and Regulation S-X. They do not include all the information and notes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and six months ended June 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019, or any other subsequent period. These financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2018, included in the Company’s annual report on Form 10-K and filed with the United States Securities and Exchange Commission (“SEC”) on March 25, 2019.

Use of Estimates

The preparation of the accompanying condensed financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the condensed financial statements, and the reported amounts of expenses during the periods reported. Actual results could differ from those estimates.

Liquidity and Substantial Doubt in Going Concern

Since inception, the Company has incurred recurring operating losses and negative cash flows from operating activities, and as of June 30, 2019, had an accumulated deficit of $280.0 million. As of June 30, 2019, the Company had approximately $17.7 million in cash, cash equivalents and marketable securities. Presently, the Company does not have sufficient cash, cash equivalents and marketable securities to enable it to fund its anticipated level of operations and meet its obligations as they become due within twelve months following the date of issuance of this Quarterly Report on Form 10-Q. The aforementioned factors raise substantial doubt about the Company’s ability to continue as a going concern for a period of one year from the issuance of these financial statements. The financial statements do not include any adjustments that might result from the outcome of this uncertainty.

On April 11, 2019, the Company closed a public offering of 5,000,000 shares of common stock at a price to the underwriter of $3.29 per share. On May 8, 2019, the underwriter purchased an additional 750,000 shares at a price to the underwriter of $3.29 per share pursuant to the exercise of the underwriter's option to purchase additional shares. The aggregate net proceeds were approximately $18.3 million, after deducting underwriting costs and estimated offering expenses.

The Company plans to raise additional funding through financing, a capital offering, a license or collaboration agreement or a combination of such sources of capital. However, there are no assurances that additional funding will be achieved and that the Company will succeed in its future operations. The Company’s inability to obtain required funding in the near future or its inability to obtain funding on favorable terms will have a material adverse effect on its operations and strategic development plan for future growth. If the Company cannot successfully raise additional capital and implement its strategic development plan, its liquidity, financial condition and business prospects will be materially and adversely affected, and it may have to cease operations.

The Company will continue to evaluate its timelines, strategic needs, and working capital requirements. There can be no assurance that if the Company attempts to raise additional capital, it will be successful in doing so on terms acceptable to the Company, or at all. Further, there can be no assurance that it will be able to gain access and/or be able to execute on securing new sources of funding, new development opportunities, successfully obtain regulatory approvals for and commercialize new products, achieve significant product revenues from its products (if approved), or achieve or sustain profitability in the future.