Filed Pursuant to 424(b)(3)
Registration No. 333-221536

PROSPECTUS

7,842,096 Shares

Common Stock

This prospectus relates to the sale or other disposition from time to time of up to 7,842,096 shares of our common stock, $0.0001 par value per share, issued and issuable to Lincoln Park Capital Fund, LLC, the selling stockholder named in this prospectus, also referred to as Lincoln Park. We are not selling any shares of common stock under this prospectus and will not receive any of the proceeds from the sale of shares of common stock by the selling stockholder.

The shares of common stock being offered by the selling stockholder have been or may be issued pursuant to the purchase agreement dated October 20, 2017 that we entered into with Lincoln Park, which we refer to in this prospectus as the Purchase Agreement. Please refer to the section of this prospectus entitled “The Lincoln Park Transaction” for a description of the Purchase Agreement and the section entitled “Selling Stockholder” for additional information regarding Lincoln Park. The prices at which Lincoln Park may sell the shares will be determined by the prevailing market price for the shares or in negotiated transactions.

The selling stockholder may sell or otherwise dispose of the shares of common stock covered by this prospectus in a number of different ways and at varying prices. We provide more information about how the selling stockholder may sell or otherwise dispose of their shares of common stock in the section entitled “Plan of Distribution.” The selling stockholder will pay all brokerage fees and commissions and similar expenses. We will pay all expenses (except brokerage fees and commissions and similar expenses) relating to the registration of the shares with the Securities and Exchange Commission.

Our common stock is listed on the Nasdaq Capital Market under the ticker symbol “ZSAN.” On November 20, 2017, the closing price of our common stock as reported on the Nasdaq Capital Market was $0.68.

Lincoln Park is an underwriter within the meaning of Section 2(a)(11) of the Securities Act.

Investing in our common stock involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” beginning on page 10 of this prospectus, and under similar headings in any amendments or supplements to this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

Prospectus dated November 21, 2017.

TABLE OF CONTENTS

We incorporate by reference important information into this prospectus. You may obtain the information incorporated by reference without charge by following the instructions under the section of this prospectus entitled “Where You Can Find More Information”. You should carefully read this prospectus as well as additional information described under the section of this prospectus entitled “Incorporation by Reference,” before deciding to invest in our common shares.

Unless the context otherwise requires, the terms “Zosano,” “we,” “us” and “our” in this prospectus refer to Zosano Pharma Corporation, and “this offering” refers to the offering contemplated in this prospectus.

Neither we nor the selling stockholder authorized anyone to provide any information or to make any representations other than those contained in this prospectus or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus is an offer to sell only the shares offered hereby, but only under the circumstances and in the jurisdictions where it is lawful to do so. The information contained in this prospectus or in any applicable free writing prospectus is current only as of its date, regardless of its time of delivery or any sale of shares of our common stock. Our business, financial condition, results of operations and prospects may have changed since that date. We are not, and the selling stockholder is not, making an offer of these securities in any jurisdiction where such offer is not permitted.

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RISK FACTORS

Investing in our securities involves a high degree of risk. Before making an investment decision with respect to our securities, we urge you to carefully consider the risks described in the “Risk Factors” sections of our most recent Annual Report on Form 10-K, as amended, and our Quarterly Reports on Form 10-Q filed with the SEC and incorporated by reference into this prospectus. These risk factors relate to our business, intellectual property, regulatory matters, and ownership of our common stock. In addition, the following risk factors present material risks and uncertainties associated with this offering. The risks and uncertainties incorporated by reference into this prospectus or described below are not the only ones we face. Additional risks and uncertainties not presently known or which we consider immaterial as of the date hereof may also have an adverse effect on our business. If any of the matters discussed in the following risk factors were to occur, our business, financial condition, results of operations, cash flows or prospects could be materially adversely affected, the market price of our securities could decline and you could lose all or part of your investment in our securities.

Risks Related to This Offering

We may not be able to access the full amounts available under the Lincoln Park Purchase Agreement, which could prevent us from accessing the capital we need to continue our operations, which could have an adverse effect on our business.

We intend to rely on the Purchase Agreement that we entered into with Lincoln Park on October 20, 2017 for our near-term capital needs. We may direct Lincoln Park to purchase up to $35.0 million of shares of our common stock over a 30-month period, commencing upon the satisfaction of certain conditions, including that the registration statement is declared effective by the SEC. Thereafter, on any trading day selected by us, we may sell shares of common stock to Lincoln Park in an amount of up to 300,000 shares per sale up to the aggregate commitment of $35.0 million. If the market price of our common stock is not below $1.50 per share on the purchase date, then the purchase amount may be increased to 350,000 shares. If the market price is not below $2.00 per share on the purchase date, then the purchase amount may be increased to 400,000 shares. Although there are no upper limits on the per share price Lincoln Park may pay to purchase our common stock, we may not sell more than $1.0 million in shares of common stock to Lincoln Park per any individual Regular Purchase. The purchase price of Regular Purchases will be based on the prevailing market prices of shares of our common stock, which will be equal to the lower of: (i) the lowest sale price on the applicable purchase date and (ii) the arithmetic average of the three lowest closing sale prices for the Company’s common stock during the ten consecutive business days ending on the business day immediately preceding such purchase date (in each case, to be appropriately adjusted for any reorganization, recapitalization, non-cash dividend, stock split, reverse split or other similar transaction that occurs on or after the date of the Purchase Agreement).

In addition to Regular Purchases, we may in our sole discretion direct Lincoln Park on each purchase date to make accelerated purchases on the following business day up to the lesser of (i) three times the number of shares directed to be purchased pursuant to such Regular Purchase or (ii) 30% of the trading volume on the accelerated purchase date at a purchase price equal to the lesser of (i) the closing sale price on the accelerated purchase date and (ii) 96% of the accelerated purchase date’s volume weighted average price (such purchases, Accelerated Purchases). We cannot submit an Accelerated Purchase notice if the market price of our common stock is below $0.75.

In addition to Regular Purchases and Accelerated Purchases described above, we may also direct Lincoln Park, on any business day that the closing price of our common stock is not below $1.00, to purchase additional amounts of our common stock, which we refer to as an additional purchase, referred to herein as an Additional Purchase, whereby, pursuant to each Additional Purchase we may sell up to $1.0 million of common stock in each Additional Purchase notice, provided, however, that at least 20 business days must have passed since the most recent Additional Purchase was completed. The purchase price for each such Additional Purchase shall be equal to the lower of (i) 96% of the purchase price under a Regular Purchase on the date we give notice for the related Additional Purchase, or (ii) $3.00 per share.

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Depending on the prevailing market price of our common stock, we may not be able to sell shares to Lincoln Park for the maximum $35.0 million over the term of the Purchase Agreement. For example, under the rules of the Nasdaq Capital Market, in no event may we issue more than 19.99% of our shares outstanding (which is 7,842,096 shares based on 39,230,097 shares outstanding prior to the signing of the Purchase Agreement) under the Purchase Agreement unless we obtain stockholder approval to issue more than 19.99%. This limitation will not apply if, at any time the Exchange Cap is reached and at all times thereafter, the average price paid for all shares issued and sold under the Purchase Agreement is equal to or greater than $0.8447, which was the consolidated closing bid price of our common stock on October 19, 2017, including an increment for the commitment shares we issued and may issue to Lincoln Park. We are not required or permitted to issue any shares of common stock under the Purchase Agreement if such issuance would breach our obligations under the rules or regulations of the Nasdaq Capital Market. In addition, Lincoln Park will not be required to purchase any shares of our common stock if such sale would result in Lincoln Park’s beneficial ownership exceeding 9.99% of the then outstanding shares of our common stock. Our inability to access a portion or the full amount available under the Purchase Agreement, in the absence of any other financing sources, could have a material adverse effect on our business.

The sale or issuance of our common stock to Lincoln Park may cause dilution and the sale of the shares of common stock acquired by Lincoln Park, or the perception that such sales may occur, could cause the price of our common stock to fall.

On October 20, 2017, we entered into the Purchase Agreement with Lincoln Park, pursuant to which Lincoln Park has committed to purchase up to $35.0 million of our common stock. Concurrently with the execution of the Purchase Agreement, we issued 227,500 shares of our common stock to Lincoln Park as an initial fee for its commitment to purchase shares of our common stock under the Purchase Agreement. Furthermore, for each additional purchase by Lincoln Park, additional commitment shares (up to a total of 227,500 shares in the aggregate) will be issued as an additional commitment fee based upon the relative proportion of the amount of shares purchased by Lincoln Park as compared to the $35.0 million limit under the Purchase Agreement. The purchase shares that may be sold pursuant to the Purchase Agreement may be sold by us to Lincoln Park at our discretion from time to time over the 30-month period commencing on the date that the registration statement, of which this prospectus is a part, is declared effective by the SEC, a final prospectus in connection therewith is filed and the other conditions of the Purchase Agreement are satisfied. The purchase price for the shares that we may sell to Lincoln Park under the Purchase Agreement will fluctuate based on the price of our common stock. Depending on market liquidity at the time, sales of such shares may cause the trading price of our common stock to fall.

We generally have the right to control the timing and amount of any sales of our shares to Lincoln Park. Additional sales of our common stock, if any, to Lincoln Park will depend upon market conditions and other factors to be determined by us. Lincoln Park may ultimately purchase all, some or none of the shares of our common stock that may be sold pursuant to the Purchase Agreement and, after it has acquired shares, Lincoln Park may sell all, some or none of those shares. Therefore, sales to Lincoln Park by us could result in substantial dilution to the interests of other holders of our common stock. Additionally, the sale of a substantial number of shares of our common stock to Lincoln Park, or the anticipation of such sales, could make it more difficult for us to sell equity or equity-related securities in the future at a time and at a price that we might otherwise wish to effect sales.

We may require additional financing to sustain our operations and without it we may not be able to continue operations.

At September 30, 2017, we had cash and cash equivalents of $13.3 million. We had an accumulated deficit of $218.4 million for the nine months ended September 30, 2017 and for the year ended December 31, 2016, an accumulated deficit of $196.8 million. We have generated significant losses to date and expect to continue to incur significant operating losses as we continue the development of our product candidate, M207. These expenditures will be incurred for development, clinical trials, regulatory compliance, infrastructure, and

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manufacturing. In the future, we will be dependent on obtaining funding from third parties, such as proceeds from the issuance of equity and debt, funded research and development programs and payments under partnership and collaborative agreements, in order to maintain our operations and meet our obligations to licensors. There is no guarantee that additional equity, debt or other funding will be available to us on acceptable terms, or at all.

We may direct Lincoln Park to purchase up to $35.0 million worth of shares of our common stock under the Purchase Agreement over a 30-month period, generally in amounts up to 300,000 shares of our common stock, which may be increased to up to 400,000 shares of our common stock depending on the market price of our common stock at the time of sale and subject to a maximum limit of $1.0 million per purchase, on any such business day. Assuming a purchase price of $0.8447 per share (the consolidated closing bid price of our common stock on October 19, 2017) and the purchase by Lincoln Park of the 7,387,096 purchase shares, gross proceeds to us would be approximately $6.2 million.

The extent we rely on Lincoln Park as a source of funding will depend on a number of factors, including the prevailing market price of our common stock and the extent to which we are able to secure funding from other sources. If obtaining sufficient funding from Lincoln Park were to prove unavailable or prohibitively dilutive, we will need to secure another source of funding in order to satisfy our working capital needs. Even if we sell all $35.0 million under the Purchase Agreement to Lincoln Park, we may still need additional capital to fully implement our business, operating and development plans. Should the financing we require to sustain our working capital needs be unavailable or prohibitively expensive when we require it, the consequences could be a material adverse effect on our business, operating results, financial condition and prospects.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and all the documents incorporated by reference herein contain forward-looking statements. All statements, other than statements of historical facts, included in this prospectus or the documents incorporated herein by reference regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects, plans and objectives of management are forward-looking statements. In some cases, you can identify these statements by forward-looking words such as “may,” “could,” “should,” “would,” “intend,” “will,” “expect,” “anticipate,” “believe,” “estimate,” “continue,” “plan,” “potential” “predict,” “project” or the negative of those terms or similar words. Any statements contained herein that are not statements of historical facts may be deemed to be forward-looking statements. You should read these statements carefully because they discuss our future expectations, contain projections of our future results of operations or of our financial condition or state other “forward-looking” information. These forward-looking statements include, among other things, statements about:

These forward-looking statements reflect our management’s beliefs and views with respect to future events and are based on estimates and assumptions as of the date of this prospectus and are subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important factors in the cautionary statements included in this prospectus, particularly in the “Risk Factors” section, that could cause actual results or events to differ materially from the forward-looking statements that we make. Moreover, we operate in a very competitive and rapidly changing environment. New risks emerge from time to time. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments that we may make.

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You should read this prospectus and the documents that we incorporate by reference herein completely and with the understanding that our actual future results may be materially different from what we expect. We do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

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INDUSTRY AND MARKET DATA

Unless otherwise indicated, information contained or incorporated by reference in this prospectus concerning our industry and the market in which we operate, including our general expectations, market position, market opportunity and market size, is based on information from various sources, including independent industry publications and market surveys by third parties privately commissioned by us that we believe to be reliable. In presenting this information, we have also made assumptions that we believe to be reasonable based on such data and other similar sources and on our knowledge of, and our experience to date in, the markets for our product candidates. These data involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the industry in which we operate are necessarily subject to a high degree of uncertainty and risk due to a variety of factors, including those described in “Risk Factors” and elsewhere in this prospectus and the documents that we incorporate by reference herein. These and other factors could cause results to differ materially from those expressed in the estimates made by the independent parties and by us. See “Cautionary Note Regarding Forward-Looking Statements.”

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THE LINCOLN PARK TRANSACTION

General

On October 20, 2017, we entered into the Purchase Agreement and the Registration Rights Agreement with Lincoln Park. Pursuant to the terms of the Purchase Agreement, Lincoln Park has agreed to purchase from us up to $35.0 million in the aggregate of our common stock (subject to certain limitations under the Purchase Agreement) from time to time over a 30-month period from the date the registration statement of which this prospectus forms a part is declared effective by the SEC, a final prospectus in connection therewith is filed and the other conditions of the Purchase Agreement are satisfied. Pursuant to the terms of the Registration Rights Agreement, we have filed with the SEC the registration statement that includes this prospectus to register for resale under the Securities Act the shares that have been or may be issued to Lincoln Park under the Purchase Agreement. The registration statement, of which this prospectus is a part, does not register all of the shares that are issuable pursuant to the Purchase Agreement. To sell additional shares to Lincoln Park under the Purchase Agreement, we will have to file one or more additional registration statements for those additional shares.

In consideration for entering into the Purchase Agreement, we issued to Lincoln Park 227,500 shares of common stock as a commitment fee and shall issue up to 227,500 additional commitment shares pro rata for no consideration, which commitment fee shares are also being registered hereunder, when and if, Lincoln Park purchases at our discretion the $35.0 million aggregate commitment. For example, if we elect, at our sole discretion, to require Lincoln Park to purchase $100,000 of our stock then we would issue 650 additional commitment shares, which is the product of $100,000 (the amount we have elected to sell) divided by $35.0 million (remaining total amount we can sell Lincoln Park pursuant to the Purchase Agreement multiplied by 227,500 (the total number of Additional Commitment Shares). The additional commitment shares will only be issued pursuant to this formula as and when we elect at our discretion to sell stock to Lincoln Park.

Other than 227,500 shares of our common stock that we have already issued to Lincoln Park pursuant to the terms of the Purchase Agreement as consideration for its commitment to purchase shares of our common stock under the Purchase Agreement, we do not have the right to commence any sales to Lincoln Park under the Purchase Agreement until the SEC has declared effective the registration statement of which this prospectus forms a part. Thereafter and upon satisfaction of the other conditions set forth in the Purchase Agreement, we may, from time to time and at our sole discretion, direct Lincoln Park to purchase shares of our common stock generally in amounts up to 300,000 shares on any single business day so long as at least one business day has passed since the most recent purchase. We can also increase the amount of our common stock to be purchased under certain circumstances to up to 400,000 shares, but not exceeding $1.0 million per purchase, plus additional “accelerated amounts” and “additional amounts” under certain circumstances. The purchase price per share is based on the market price of our common stock immediately preceding the time of sale as computed under the Purchase Agreement. Lincoln Park may not assign or transfer its rights and obligations under the Purchase Agreement.

In addition, the Company is subject to a cap on the number of shares that may be issuable under the Purchase Agreement to the extent that the aggregate number of shares issued would breach the Company’s obligations under the Nasdaq Capital Market, which prohibits the issuance of more than 19.99%, or 7,842,096 shares, of the Company’s outstanding shares of common stock as of August 4, 2017, unless stockholder approval is obtained. This limitation will not apply if, at any time the Exchange Cap is reached and at all times thereafter, the average price paid for all shares issued and sold under the Purchase Agreement is equal to or greater than $0.8447, which was the consolidated closing bid price of our common stock on October 19, 2017, including an increment for the commitment shares we issued and may issue to Lincoln Park. We are not required or permitted to issue any shares of common stock under the Purchase Agreement if such issuance would breach our obligations under the rules or regulations of the Nasdaq Capital Market.

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Purchase of Shares Under the Purchase Agreement

Under the Purchase Agreement, from and after the Commencement, on any business day selected by us on which the closing price of our common stock is not below $0.50 per share (to be appropriately adjusted as provided in the Purchase Agreement for any reorganization, recapitalization, non-cash dividend, stock split or other similar transaction), we may direct Lincoln Park to purchase up to 300,000 shares of our common stock, so long as one business day has passed since the last purchase. On any day that the closing sale price of our common stock is not below (a) $1.50, the purchase amount may be increased, at our sole discretion, to up to 350,000 shares of our common stock per purchase, and (b) $2.00, the purchase amount may be increased, at our sole discretion, to up to 400,000 shares of our common stock per purchase, provided in each instance that the amount cannot exceed $1.0 million. Lincoln Park will not be required to purchase any shares of our common stock if such sale would result in Lincoln Park’s beneficial ownership exceeding 9.99% of the then outstanding shares of our common stock. The purchase price per share for each such Regular Purchase will be equal to the lower of:

In addition to Regular Purchases described above, we may also direct Lincoln Park, on any business day on which we have properly submitted a Regular Purchase notice and the closing price of our common stock is not below $0.75 per share (to be appropriately adjusted as provided in the Purchase Agreement for any reorganization, recapitalization, non-cash dividend, stock split or other similar transaction), to purchase an additional amount of our common stock (such purchase, an Accelerated Purchase), not to exceed the lesser of:

The purchase price per share for each such Accelerated Purchase will be equal to the lower of:

In addition to Regular Purchases and Accelerated Purchases described above, we may also direct Lincoln Park, on any business day that the closing price of our common stock is not below $1.00 (to be appropriately adjusted as provided in the Purchase Agreement for any reorganization, recapitalization, non-cash dividend, stock split or other similar transaction), to purchase additional amounts of our common stock, which we refer to as an Additional Purchase, whereby, pursuant to each Additional Purchase we may sell up to $1.0 million of common stock in each Additional Purchase notice, provided, however, that at least 20 business days must have passed since the most recent Additional Purchase notice was completed. The purchase price for each such Additional Purchase shall be equal to the lower of (i) 96% of the purchase price under a Regular Purchase on the date we give notice for the related Additional Purchase, or (ii) $3.00 per share.

Other than as set forth above, there are no trading volume requirements or restrictions under the Purchase Agreement, and we will control the timing and amount of any sales of our common stock to Lincoln Park.

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Events of Default

Events of default under the Purchase Agreement include the following:

Lincoln Park does not have the right to terminate the Purchase Agreement upon any of the events of default set forth above. During an event of default or any event which, after notice or lapse of time, would reasonably be expected to become an event of default, all of which are outside of Lincoln Park’s control, we cannot initiate any Regular Purchases, Accelerated Purchases or Additional Purchases under the Purchase Agreement.

Our Termination Rights

We have the unconditional right, at any time, for any reason and without any payment or liability to us, to give notice to Lincoln Park to terminate the Purchase Agreement. In the event of bankruptcy proceedings by or against us, the Purchase Agreement will automatically terminate without action of any party.

No Short-Selling or Hedging by Lincoln Park

Lincoln Park has agreed that neither it nor any of its affiliates shall engage in any direct or indirect short-selling or hedging of our common stock during any time prior to the termination of the Purchase Agreement.

Effect of Performance of the Purchase Agreement on Our Stockholders

All shares of common stock registered in this offering are expected to be freely tradable. It is anticipated that shares registered in this offering will be sold over a period of up to 30 months commencing on the date that the registration statement including this prospectus becomes effective. The sale by Lincoln Park of a significant amount of shares registered in this offering at any given time could cause the market price of our common stock

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to decline and to be highly volatile. Lincoln Park may ultimately purchase all, some or none of the shares of common stock not yet issued but registered in this offering (subject to the limitations in the Purchase Agreement). If we sell these shares to Lincoln Park, Lincoln Park may sell all, some or none of such shares. Therefore, sales to Lincoln Park by us under the Purchase Agreement may result in substantial dilution to the interests of other holders of our common stock. In addition, if we sell a substantial number of shares to Lincoln Park under the Purchase Agreement, or if investors expect that we will do so, the actual sales of shares or the mere existence of our arrangement with Lincoln Park may make it more difficult for us to sell equity or equity-related securities in the future at a time and at a price that we might otherwise wish to effect such sales. However, we have the right to control the timing and amount of any sales of our shares to Lincoln Park and the Purchase Agreement may be terminated by us at any time, at our discretion, without any cost to us.

Pursuant to the terms of the Purchase Agreement, we have the right, but not the obligation, to direct Lincoln Park to purchase up to $35.0 million of our common stock. We have registered only a portion of the shares issuable under the Purchase Agreement and, therefore, we may seek to issue and sell to Lincoln Park under the Purchase Agreement more shares of our common stock than are offered under this prospectus. If we choose to do so, we must first register for resale under the Securities Act any such additional shares, which could cause additional substantial dilution to our stockholders. The number of shares ultimately offered for resale by Lincoln Park under this prospectus is dependent upon the number of shares we direct Lincoln Park to purchase under the Purchase Agreement.

The following table sets forth the amount of proceeds we would receive from Lincoln Park from the sale of shares at varying purchase prices:

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USE OF PROCEEDS

This prospectus relates to shares of our common stock that may be offered and sold from time to time by Lincoln Park. We will receive no proceeds from the sale of shares of common stock by Lincoln Park in this offering.

We may receive up to $35.0 million in aggregate gross proceeds if we issue to Lincoln Park all of the shares issuable pursuant to the Purchase Agreement. We will incur all costs associated with this registration statement and prospectus.

We intend to use any proceeds that we receive under the Purchase Agreement to fund the long term safety study for our lead product candidate, M207, and for and general corporate purposes. This anticipated use of net proceeds from the sale of our common stock to Lincoln Park under the Purchase Agreement represents our intentions based upon our current plans and business conditions. The amounts we actually expend in these areas, and the timing thereof, may vary significantly from our current intentions and will depend upon a number of factors, as we are unable to predict the timing or amount of potential issuances of all of the shares offered hereby.

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DETERMINATION OF OFFERING PRICE

The prices at which the shares covered by this prospectus may actually be sold will be determined by the prevailing public market price for shares of our common stock, by negotiations between the selling stockholder and buyers of our common stock in private transactions or as otherwise described in the “Plan of Distribution.”

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SELLING STOCKHOLDER

The following table sets forth certain information regarding Lincoln Park, the selling stockholder, and the shares of common stock beneficially owned by it, which information is available to us as of November 3, 2017. Lincoln Park may offer the shares under this prospectus from time to time and may elect to sell some, all or none of the shares set forth under this prospectus. However, for the purposes of the table below, we have assumed that, after completion of the offering, none of the shares covered by this prospectus will be held by Lincoln Park. In addition, Lincoln Park may have sold, transferred or otherwise disposed of all or a portion of its shares of common stock since the date on which it provided information for this table. We have not made independent inquiries about such transfers or dispositions. See the section entitled “Plan of Distribution.”

Beneficial ownership is determined in accordance with Rule 13d-3(d) promulgated by the SEC under the Exchange Act. The percentage of shares beneficially owned before the offering is based on 39,460,931 shares of our common stock outstanding as of November 3, 2017.

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DILUTION

Purchasers of our common stock in this offering will experience an immediate dilution of the net tangible book value per share of our common stock. Our net tangible book value as of September 30, 2017 was approximately $14.2 million, or $0.36 per share of our common stock (based upon 39,233,431 shares of our common stock outstanding). Net tangible book value per share is equal to our total tangible assets less our total liabilities, divided by the number of shares of our outstanding common stock.

Dilution in net tangible book value per share represents the difference between the amount per share paid by purchasers of common stock in this offering, assuming a purchase price of $0.71 per share (the closing price of our common stock on November 3, 2017), and the as adjusted net tangible book value per share of common stock immediately after the completion of this offering. Therefore, after giving effect to our assumed receipt of $5.2 million in estimated net proceeds from the issuance of 7,387,096 shares of common stock under the Purchase Agreement and registered in this offering (assuming a purchase price of $0.71 per share for 7,387,096 shares, the issuance of 261,591 commitment shares for no additional cash consideration, offering expenses of $50,000, and assuming all such sales and issuances were made on September 30, 2017), our as adjusted net tangible book value as of September 30, 2017 would have been $19.4 million, or $0.41 per share. This would represent an immediate increase in the net tangible book value of $0.05 per share to existing stockholders and an immediate dilution of $0.30 per share to new investors purchasing shares of our common stock in this offering. The following table illustrates this per share dilution:

The number of shares of our common stock reflected in the discussion and the table above is based on 39,233,431 shares of our common stock outstanding as of September 30, 2017, and excludes:

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To the extent that any options or warrants are exercised, new options are issued under our equity incentive plans or we otherwise issue additional shares of common stock in the future at a price less than the public offering price, there may be further dilution to new investors purchasing common stock in this offering.

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DIVIDEND POLICY

We have never declared or paid any cash dividends on our capital stock. We currently expect to retain all available funds and future earnings, if any, to finance the growth and development of our business. We do not expect to pay any cash dividends on our common stock in the foreseeable future. Payment of future dividends, if any, will be at the discretion of our board of directors and will depend on our financial condition, results of operations, capital requirements, restrictions contained in any future financing instruments, provisions of applicable law and other factors the board of directors deems relevant. Additionally, our secured term loan facility with Hercules contains covenants that restrict our ability to pay dividends.

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PRINCIPAL STOCKHOLDERS

The following table sets forth certain information with respect to beneficial ownership of our common stock, as of November 3, 2017:

Beneficial ownership is determined in accordance with the rules of the SEC. In computing the number of shares beneficially owned by a person and the percentage ownership of that person, shares of common stock subject to options held by that person that are currently exercisable or exercisable within 60 days of November 3, 2017 are deemed outstanding, but are not deemed outstanding for computing the percentage ownership of any other person. To our knowledge, except as set forth in the footnotes to this table and subject to applicable community property laws, each person named in the table has sole voting and investment power with respect to the shares set forth opposite such person’s name. Except as otherwise indicated, the address of each of the persons in this table is c/o Zosano Pharma Corporation, 34790 Ardentech Court, Fremont, California 94555.

Each stockholder’s percentage ownership is determined in accordance with Rule 13d-3 under the Exchange Act and is based on 39,460,931 shares of our common stock outstanding as of November 3, 2017.

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PLAN OF DISTRIBUTION

An aggregate of up to 7,842,096 shares of our common stock may be offered by this prospectus by Lincoln Park pursuant to the Purchase Agreement. The common stock may be sold or distributed from time to time by Lincoln Park directly to one or more purchasers or through brokers, dealers, or underwriters who may act solely as agents at market prices prevailing at the time of sale, at prices related to the prevailing market prices, at negotiated prices, or at fixed prices, which may be changed. The sale of the common stock offered by this prospectus could be effected in one or more of the following methods:

In order to comply with the securities laws of certain states, if applicable, the shares may be sold only through registered or licensed brokers or dealers. In addition, in certain states, the shares may not be sold unless they have been registered or qualified for sale in the state or an exemption from the state’s registration or qualification requirement is available and complied with.

Lincoln Park is an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act.

Lincoln Park has informed us that it intends to use an unaffiliated broker-dealer to effectuate all sales, if any, of the common stock that it may purchase from us pursuant to the Purchase Agreement. Such sales will be made at prices and at terms then prevailing or at prices related to the then current market price. Each such unaffiliated broker-dealer will be an underwriter within the meaning of Section 2(a)(11) of the Securities Act. Lincoln Park has informed us that each such broker-dealer will receive commissions from Lincoln Park that will not exceed customary brokerage commissions.

Brokers, dealers, underwriters or agents participating in the distribution of the shares offered by this prospectus may receive compensation in the form of commissions, discounts, or concessions from the purchasers for whom the broker-dealers may act as agent, of the common stock sold by Lincoln Park through this prospectus. The compensation paid to any such particular broker-dealer by any such purchasers of common stock sold by Lincoln Park may be less than or in excess of customary commissions. Neither we nor Lincoln Park can presently estimate the amount of compensation that any agent will receive.

We know of no existing arrangements between Lincoln Park or any other stockholder, broker, dealer, underwriter or agent relating to the sale or distribution of the shares offered by this prospectus.

We may from time to time file with the SEC one or more supplements to this prospectus or amendments to the registration statement of which this prospectus forms a part to amend, supplement or update information contained in this prospectus, including, if and when required under the Securities Act, to disclose certain information relating to a particular sale of shares offered by this prospectus by the selling stockholder, including the names of any brokers, dealers, underwriters or agents participating in the distribution of such shares by the selling stockholder, any compensation paid by Lincoln Park to any such brokers, dealers, underwriters or agents, and any other required information.

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We will pay the expenses incident to the registration under the Securities Act of the offer and sale of the shares covered by this prospectus by Lincoln Park. We have agreed to indemnify Lincoln Park and certain other persons against certain liabilities in connection with the offering of shares of common stock offered hereby, including liabilities arising under the Securities Act or, if such indemnity is unavailable, to contribute amounts required to be paid in respect of such liabilities. Lincoln Park has agreed to indemnify us against liabilities under the Securities Act that may arise from certain written information furnished to us by Lincoln Park specifically for use in this prospectus or, if such indemnity is unavailable, to contribute amounts required to be paid in respect of such liabilities.

Lincoln Park has represented to us that at no time prior to the Purchase Agreement has it or its agents, representatives or affiliates engaged in or effected, in any manner whatsoever, directly or indirectly, any short sale (as such term is defined in Rule 200 of Regulation SHO of the Exchange Act) of our common stock or any hedging transaction, which establishes a net short position with respect to our common stock. Lincoln Park has agreed that during the term of the Purchase Agreement, it, its agents, representatives or affiliates will not enter into or effect, directly or indirectly, any of the foregoing transactions.

We have advised Lincoln Park that it is required to comply with Regulation M promulgated under the Exchange Act. With certain exceptions, Regulation M precludes Lincoln Park, any affiliated purchasers, and any broker-dealer or other person who participates in the distribution from bidding for or purchasing, or attempting to induce any person to bid for or purchase any security which is the subject of the distribution until the entire distribution is complete. Regulation M also prohibits any bids or purchases made in order to stabilize the price of a security in connection with the distribution of that security. All of the foregoing may affect the marketability of the securities offered by this prospectus.

This offering will terminate on the date that all shares offered by this prospectus have been sold by Lincoln Park.

Our common stock is quoted on The Nasdaq Capital Market under the symbol “ZSAN”.

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DESCRIPTION OF CAPITAL STOCK

The following is a summary of all material characteristics of our capital stock as set forth in our amended and restated certificate of incorporation and our amended and restated bylaws. The summary does not purport to be complete and is qualified in its entirety by reference to our amended and restated certificate of incorporation and amended and restated bylaws, all of which are incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and the applicable provisions of Delaware law.

General

Our authorized capital stock consists of 100,000,000 shares of common stock, par value $0.0001 per share, and 5,000,000 shares of preferred stock, par value $0.0001 per share, all of which shares of preferred stock are undesignated. As of November 3, 2017, we had 39,460,931 shares of common stock issued and outstanding, which were held of record by 28 holders.

Common Stock

Voting rights. Holders of our common stock are entitled to one vote per share held of record on all matters to be voted upon by our stockholders. The election of directors by our stockholders is determined by a plurality of the votes cast by the stockholders entitled to vote on the election and we have a classified board of directors that is divided into three classes with staggered three-year terms. Other matters subject to a vote by our stockholders are decided by the affirmative vote of our stockholders having a majority in voting power of the votes cast by the stockholders present or represented and voting on such matter. Our common stock does not have cumulative voting rights.

Dividend rights. Subject to preferences that may be applicable to the holders of any outstanding shares of our preferred stock, the holders of our common stock are entitled to receive such lawful dividends as may be declared by our board of directors.

Liquidation and dissolution. In the event of our liquidation, dissolution or winding up, and subject to the rights of the holders of any outstanding shares of our preferred stock, the holders of shares of our common stock will be entitled to receive pro rata all of our remaining assets available for distribution to our stockholders.

Other rights and restrictions. Our amended and restated certificate of incorporation does not permit us to redeem shares of our common stock at our election, provide for a sinking fund with respect to our common stock or provide for the granting of preemptive rights to any stockholder. All outstanding shares are fully paid and nonassessable. Our secured term loan facility with Hercules contains covenants that restrict our ability to pay dividends.

Preferred Stock

Pursuant to our amended and restated certificate of incorporation, our board of directors is authorized, without stockholder approval, from time to time to issue up to 5,000,000 shares of preferred stock in one or more series, each of the series to have such rights and preferences, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences, as the board of directors may determine. The rights of the holders of common stock will be subject to, and may be adversely affected by, the rights of holders of any preferred stock that we may issue in the future. The issuance of preferred stock, while providing desirable flexibility in connection with possible acquisitions and other corporate purposes, could have the effect of making it more difficult for others to acquire, or of discouraging others from attempting to acquire, a majority of our outstanding voting stock. We have no current plans to issue any shares of preferred stock.

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Options and Warrants

As of November 3, 2017, options to purchase 1,867,831 shares of our common stock were outstanding under our 2012 Stock Incentive Plan and our Amended and Restated 2014 Equity and Incentive Plan, at a weighted average exercise price of $1.34 per share.

As of November 3, 2017, we had outstanding warrants, held by Hercules, to purchase 31,674 shares of the Company’s common stock at an exercise price of $8.84 and 40,705 shares of the Company’s common stock at an exercise price of $7.37 per share. These warrants are exercisable by Hercules at any time, in whole or in part, until January 30, 2020 and June 23, 2020, respectively. The exercise prices are subject to proportional adjustment upon the subdivision or combination of shares of the common stock, or an appropriate adjustment by the board at the time of a merger event, as defined in the applicable warrant agreement, or a reclassification of shares (by combination, reclassification, exchange or subdivision of securities or otherwise).

In August 2016, we completed a private placement to certain investors of 4,800,000 shares of our common stock and Series A and Series B warrants to purchase an aggregate of 9,600,000 shares of common stock. The Series A warrants are no longer exercisable as of August 2017. As of November 3, 2017, we had outstanding Series B warrants to purchase 3,918,175 shares of our common stock at an exercise price of $1.55 per share. The exercise price is subject to proportional adjustment upon the subdivision or combination of shares of the common stock (by any stock split, stock dividend, recapitalization, reverse stock split, or otherwise), but the exercise price cannot be reduced below the par value of the common stock. The Series B warrants are exercisable at any time, in whole or in part, until August 19, 2021.

Registration Rights

On October 20, 2017, we entered into the Registration Rights Agreement with Lincoln Park pursuant to which we agreed to file with the SEC one or more registration statements as necessary to register for sale under the Securities Act shares of common stock that we issued or may issue to Lincoln Park under the Purchase Agreement. We are registering 7,842,096 of such shares of common stock for resale pursuant to the registration statement of which this prospectus is a part as required by the Registration Rights Agreement.

In August 2016, we entered into a securities purchase agreement, or the Securities Purchase Agreement, in connection with a private placement, pursuant to which we granted certain investors certain registration rights with respect to the shares purchased as well as the shares issuable upon exercise of the warrants. In particular, the Securities Purchase Agreement required us to file a registration statement with the SEC to register the sale of such shares within 30 days of the consummation of the private placement and to maintain continuous effectiveness of the registration statement. A registration statement relating to such shares was filed on September 9, 2016 and declared effective by the SEC on September 23, 2016.

On June 23, 2015, we issued a warrant, or the Warrant, to Hercules to purchase 40,705 shares of the Company’s common stock at an exercise price of $7.37 per share. Pursuant to the Warrant, we agreed, among other things, that we would file with the SEC a registration statement to register the sale of the shares issuable upon exercise of the Warrant within 30 days of the Company becoming eligible to use a Form S-3 registration statement to register such shares. A registration statement relating to such shares was filed on September 9, 2016 and declared effective by the SEC on September 23, 2016.

Anti-Takeover Effects of Provisions of Delaware Law and Our Charter and By-laws

Provisions of Delaware law and our amended and restated certificate of incorporation and amended and restated bylaws could make it more difficult to acquire us by means of a tender offer, a proxy contest, open market purchases, removal of incumbent directors and otherwise. These provisions, summarized below, are expected to discourage types of coercive takeover practices and inadequate takeover bids and to encourage persons seeking to

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acquire control of us to first negotiate with us. We believe that the benefits of increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging takeover or acquisition proposals because negotiation of these proposals could result in an improvement of their terms.

We must comply with Section 203 of the Delaware General Corporation Law, an anti-takeover law. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a period of three years following the date the person became an interested stockholder, unless the business combination or the transaction in which the person became an interested stockholder is approved in a prescribed manner. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to an interested stockholder. An “interested stockholder” includes a person who, together with affiliates and associates, owns, or did own within three years before the determination of interested stockholder status, 15% or more of the corporation’s voting stock. The existence of this provision generally will have an anti-takeover effect for transactions not approved in advance by the board of directors, including discouraging attempts that might result in a premium over the market price for the shares of common stock held by stockholders.

Our amended and restated certificate of incorporation and our amended and restated bylaws require that any action required or permitted to be taken by our stockholders must be effected at a duly called annual or special meeting of the stockholders and may not be effected by a consent in writing. In addition, special meetings of our stockholders may be called only by the board of directors and some of our officers. Our amended and restated bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of stockholders, including proposed nominations of candidates for election to our board of directors. Our amended and restated certificate of incorporation and amended and restated bylaws also provide for our board of directors to be divided into three classes, with each class serving staggered three-year terms. These provisions may have the effect of deterring hostile takeovers or delaying changes in our control or management.

Listing on the Nasdaq Capital Market

Our common stock is listed on the Nasdaq Capital Market under the symbol “ZSAN.”

Authorized but Unissued Shares

The authorized but unissued shares of common stock and preferred stock are available for future issuance without stockholder approval, subject to any limitations imposed by the Nasdaq Listing Rules. These additional shares may be used for a variety of corporate finance transactions, acquisitions and employee benefit plans. The existence of authorized but unissued and unreserved common stock and preferred stock could make it more difficult or discourage an attempt to obtain control of us by means of a proxy contest, tender offer, merger or otherwise.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

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LEGAL MATTERS

Certain legal matters relating to the issuance of the securities offered by this prospectus will be passed upon for us by Foley Hoag LLP, Boston, Massachusetts. Jeffrey L. Quillen, Esq., a partner of Foley Hoag LLP, is our corporate secretary.

EXPERTS

The consolidated balance sheets of Zosano Pharma Corporation and the related statements of operations, stockholders’ deficit, and cash flows for each of the years in the two-year period ended December 31, 2016 and 2015, have been audited by Marcum LLP, an independent registered public accounting firm, as stated in their report which is incorporated by reference into this prospectus and elsewhere in the registration statement of which this prospectus is a part. Such consolidated financial statements are incorporated by reference herein in reliance on the report of such firm given upon their authority as experts in accounting and auditing. The report on the consolidated financial statements contains an explanatory paragraph regarding the Company’s ability to continue as a going concern.

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INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” information into this prospectus, which means that we can disclose important information to you by referring you to another document filed separately with the SEC. The SEC file number for the documents incorporated by reference in this prospectus is 001-36570. The documents incorporated by reference into this prospectus contain important information that you should read about us.

The following documents are incorporated by reference into this document:

We also incorporate by reference into this prospectus all documents (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items) that are filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including those made after the date of the initial registration statement of which this prospectus is a part and prior to the effectiveness of such registration statement and all documents that are subsequently filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus but prior to the termination of the offering. These documents include periodic reports, such as Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as proxy statements.

Any statement contained herein or in a document incorporated or deemed to be incorporated by reference into this document will be deemed to be modified or superseded for purposes of the document to the extent that a statement contained in this document or any other subsequently filed document that is also incorporated or deemed to be incorporated by reference into this document modifies or supersedes the statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus

We will furnish without charge to each person, including any beneficial owner, to whom a prospectus is delivered, upon written or oral request, a copy of any or all of the documents incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits that are specifically incorporated by reference into such documents. You should direct any requests for documents to:

Zosano Pharma Corporation

34790 Ardentech Court

Fremont, California 94555

Attention: Investor Relations

Telephone: (510) 745-1200

In addition, copies of any or all of the documents incorporated herein by reference may be accessed at our website at http://www.zosanopharma.com. The information on such website is not incorporated by reference and is not a part of this prospectus.

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WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-1 under the Securities Act, with respect to the shares of common stock being offered by this prospectus. This prospectus does not contain all of the information in the registration statement and its exhibits. For further information with respect to us and the common stock offered by this prospectus, we refer you to the registration statement and its exhibits. Statements contained in this prospectus as to the contents of any contract or any other document referred to are not necessarily complete, and in each instance, we refer you to the copy of the contract or other document filed as an exhibit to the registration statement. Each of these statements is qualified in all respects by this reference. You should rely only on information contained in, or incorporated by reference into, this prospectus. We have not authorized anyone to provide you with information different from that contained in this prospectus or incorporated by reference in this prospectus.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document we file with the SEC at the SEC’s public reference room at 100 F Street NE, Room 1580, Washington, D.C. 20549 on official business days during the hours of 10:00 am to 3:00 pm. You may obtain information on the operation of the SEC’s public reference facilities by calling the SEC at 1-800-SEC-0330. You can request copies of these documents, upon payment of a duplicating fee, by writing to the SEC at its principal office at 100 F Street NE, Room 1580, Washington, D.C. 20549-1004. The SEC maintains an Internet website at http://www.sec.gov that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC. Our SEC filings are accessible through the Internet at that website. Our reports on Forms 10-K, 10-Q and 8-K, and amendments to those reports, are also available, free of charge, as soon as reasonably practicable after these reports are filed with the SEC, at our website at www.zosanopharma.com. The content contained in, or that can be accessed through, our website is not a part of this prospectus.

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7,842,096 Shares

Common Stock

PROSPECTUS

November 21, 2017.