As filed with the Securities and Exchange Commission on January 25, 2013

No. 333-185645

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

AMENDMENT NO. 1

TO

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

SAGENT PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware	98-0536317
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)

c/o Sagent Pharmaceuticals, Inc.

1901 N. Roselle Road, Suite 700

Schaumburg, Illinois 60195

(847) 908-1600

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Michael Logerfo

Executive Vice President, Chief Legal Officer and Corporate Secretary

c/o Sagent Pharmaceuticals, Inc.

1901 North Roselle Road, Suite 700

Schaumburg, Illinois 60195

(847) 908-1600

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies of all communications, including communications sent to agent for service, should be sent to:

Dennis M. Myers, P.C.

Kirkland & Ellis LLP

300 North LaSalle

Chicago, Illinois 60654

(312) 862-2000

Approximate date of commencement of proposed sale to the public: From time to time after the effectiveness of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box:    ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box:    x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    ¨

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.    ¨

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.    ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	¨	Accelerated filer	x
Non-accelerated filer	¨  (Do not check if a smaller reporting company)	Smaller reporting company	¨

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment that specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act, as amended, or until this registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this prospectus is not complete and may be changed. We and any selling stockholders may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not the solicitation of an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

PROSPECTUS

Subject to completion, dated January 25, 2013

24,052,223 Shares

SAGENT PHARMACEUTICALS, INC.

Common Stock

We may offer, from time to time, up to 9,000,000 shares of our common stock, and selling stockholders may offer, from time to time, up to an additional 15,052,223 shares of our common stock. Unless otherwise provided in the applicable prospectus supplement, we intend to use net proceeds from the sale of shares of common stock by us for working capital and general corporate purposes. We will not receive any proceeds from the sale of shares of common stock offered by any selling stockholders. We will bear a portion of the expenses of the offering of common stock, except that selling stockholders will pay any applicable underwriting fees, discounts or commissions and certain transfer taxes with respect to their shares of common stock.

Our registration of the shares of common stock covered by this prospectus does not mean that we or any selling stockholders will offer or sell any of the shares. We and/or selling stockholders may sell 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 we and/or selling stockholders may sell our respective shares in the section entitled “Plan of Distribution” beginning on page 6.

Our common stock is traded on the NASDAQ Global Market under the symbol “SGNT.” On January 22, 2013, the last reported sale price of our common stock on the NASDAQ Global Market was $16.07 per share.

Investing in our common stock involves risks that are described in the “Risk Factors” section beginning on page 2 of 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.

The date of this prospectus is                     , 2013

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS		i
OUR COMPANY		1
RISK FACTORS		2
FORWARD-LOOKING STATEMENTS		2
USE OF PROCEEDS		4
SELLING STOCKHOLDERS		5
PLAN OF DISTRIBUTION		6
LEGAL MATTERS		8
EXPERTS		8
WHERE YOU CAN FIND MORE INFORMATION		8
INCORPORATION BY REFERENCE OF CERTAIN DOCUMENTS		9

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or the “SEC,” using a “shelf” registration process. Specific information about the terms of an offering will be included in a prospectus or a prospectus supplement relating to each offering of shares. The prospectus supplement may also add, update or change information included in this prospectus. You should read both this prospectus and any applicable prospectus supplement, together with additional information described below under the caption “Where You Can Find More Information” and “Incorporation by Reference of Certain Documents.” You should also carefully consider, among other things, the matters discussed in the section entitled “Risk Factors.”

We are responsible for the information contained and incorporated by reference in this prospectus, any applicable prospectus supplements and any related free writing prospectus we prepare or authorize. Neither we, any selling stockholders nor any underwriter has authorized anyone to provide information different from that contained in this prospectus and the documents incorporated by reference herein.

The information contained in this prospectus, in any prospectus supplement or in any document incorporated by reference is accurate only as of its date, regardless of the time of delivery of this prospectus or any sale of common stock.

This prospectus is not an offer to sell or solicitation of an offer to buy these shares of common stock in any circumstances under which or jurisdiction in which the offer or solicitation is unlawful.

Unless the context otherwise indicates, the terms “Sagent,” “Company,” “we,” “us,” and “our” as used in this prospectus refer to Sagent Pharmaceuticals, Inc. and its subsidiaries. Unless the context otherwise indicates, the phrase “this prospectus” refers to this prospectus and any applicable prospectus supplement(s).

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OUR COMPANY

We are a specialty pharmaceutical company that develops and sources products that we sell primarily in the United States of America through our highly experienced sales and marketing team. With a primary focus on generic injectable pharmaceuticals, we offer our customers a broad range of products across anti-infective, oncolytic and critical care indications in a variety of presentations, including single- and multi-dose vials, pre-filled ready-to-use syringes and premix bags. We generally seek to develop injectable products including those where the form or packaging of the product can be enhanced to improve delivery, product safety or end-user convenience. Our management team includes industry veterans who have previously served critical functions at other injectable pharmaceutical companies and key customer groups and have long-standing relationships with customers, regulatory agencies and suppliers. We have rapidly established a growing and diverse product portfolio and product pipeline as a result of our innovative business model, which combines an extensive network of international development, sourcing and manufacturing collaborations with our proven and experienced U.S.-based regulatory, quality assurance, business development, project management, and sales and marketing teams.

Our corporate headquarters are located at 1901 North Roselle Road, Suite 700, Schaumburg, Illinois 60195. Our telephone number is (847) 908-1600. Our website address is www.sagentpharma.com. The information on our website is not deemed, and you should not consider such information, to be part of this prospectus.

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RISK FACTORS

Our business is subject to uncertainties and risks. You should carefully consider and evaluate all of the information included and incorporated by reference in this prospectus, including the risk factors incorporated by reference from our most recent annual report on Form 10-K, as updated by our quarterly reports on Form 10-Q and other filings we make with the SEC. If any of the risks and uncertainties described in this prospectus, any applicable prospectus supplement or the documents incorporated by reference herein or therein actually occur, our business, financial condition, liquidity and results of operations could be adversely affected in a material way. This could cause the trading price of our common stock to decline, perhaps significantly, and you may lose part or all of your investment.

FORWARD-LOOKING STATEMENTS

This prospectus, any applicable prospectus supplement and the documents incorporated by reference herein or therein contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that are based on current expectations, estimates, forecasts and projections about us, our future performance, our liquidity, our beliefs and management’s assumptions. Words such as “anticipate,” “estimate,” “expect,” “project,” “plan,” “intend,” “believe,” “may,” “will,” “should,” “can have,” “likely” and variations of such words and similar expressions are intended to identify such forward-looking statements. For example, all statements we make relating to our estimated and projected costs, expenditures, cash flows, growth rates and financial results, our plans and objectives for future operations, growth or initiatives, strategies, or the expected outcome or impact of pending or threatened litigation are forward-looking statements. All forward-looking statements speak only as of the date on which they are made. These statements are not guarantees of future performance and involve certain risks, uncertainties and assumptions concerning future events that are difficult to predict. Therefore, actual future events or results may differ materially from these statements. We believe that the factors that could cause our actual results to differ materially include the factors that we describe under the caption “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2011, which is incorporated by reference. These factors, risks and uncertainties include, but are not limited to, the following:

• we rely on our business partners for the manufacture of our products, and if our business partners fail to supply us with high-quality active pharmaceutical ingredient (“API”) or finished products in the quantities we require on a timely basis, sales of our products could be delayed or prevented, our revenues could decline and we may not achieve profitability;

• if we or any of our business partners are unable to comply with the quality and regulatory standards applicable to pharmaceutical drug manufacturers, or if approvals of pending applications are delayed as a result of quality or regulatory compliance concerns or merely backlogs at the US Food and Drug Administration (“FDA”), we may be unable to meet the demand for our products, may lose potential revenues and may not achieve profitability;

• changes in the regulations, enforcement procedures or regulatory policies established by the FDA and other regulatory agencies are expected to increase the costs and time of development of our products and could delay or prevent sales of our products and our revenues could decline and we may not achieve profitability;

• three of our products - heparin, levofloxacin in pre-mix bags, and cefepime, each of which is supplied to us by a single vendor - represent a significant portion of our net revenues and, if the volume or pricing of any of these products declines, or we are unable to satisfy market demand for these products, it could have a material adverse effect on our business, financial position and results of operations;

• we participate in highly competitive markets, dominated by a few large competitors, and if we are unable to compete successfully, our revenues could decline and our future profitability could be jeopardized;

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• if we are unable to continue to develop and commercialize new products in a timely and cost-effective manner, we may not achieve our expected revenue growth or profitability or such revenue growth and profitability, if any, could be delayed;

• if we are unable to maintain our group purchasing organization and distributor relationships, our revenues could decline and future profitability would be jeopardized;

• we rely on a limited number of pharmaceutical wholesalers to distribute our products;

• we depend to a significant degree upon our key personnel, the loss of whom could adversely affect our operations;

• we may be exposed to product liability claims that could cause us to incur significant costs or cease selling some of our products;

• if reimbursement by government-sponsored or private sector insurance programs for our current or future products is reduced or modified, our business could suffer;

• current and future decline of national and international economic conditions could adversely affect our operations;

• we are subject to risks associated with managing our international network of collaborations which include business partners and other suppliers of components, API and finished products located throughout the world;

• we may never realize the expected benefits from our investment in our Kanghong Sagent (Chengdu) Pharmaceutical Corporation Limited joint venture in China and the joint venture may require additional capital investment to continue its operations; and

• we may seek to engage in strategic transactions, including the acquisition of products or businesses, that could have a variety of negative consequences, and we may not realize the intended benefits of such transactions.

These factors should not be construed as exhaustive and should be read in conjunction with the other cautionary statements included in this prospectus, any applicable prospectus supplement and the documents incorporated by reference herein or therein. These risks and uncertainties, as well as other risks of which we are not aware or which we currently do not believe to be material, may cause our actual future results to be materially different than those expressed in our forward-looking statements. We caution you not to place undue reliance on these forward-looking statements. We do not undertake any obligation to make any revisions to these forward-looking statements to reflect events or circumstances after the date made or to reflect the occurrence of unanticipated events, except as required by law, including the securities laws of the United States and rules and regulations of the SEC.

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USE OF PROCEEDS

Unless otherwise provided in the applicable prospectus supplement, we intend to use the net proceeds from any sale of shares we offer under this prospectus for working capital and general corporate purposes. We will not receive any proceeds from the sale of shares of common stock offered by selling stockholders under this prospectus.

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SELLING STOCKHOLDERS

Information about selling stockholders, if any, including their identities, the amount of common stock owned by each selling stockholder prior to the offering, the amount of common stock to be offered by each selling stockholder and the amount of common stock to be owned by each selling stockholder after completion of the offering, will be set forth in a prospectus supplement, in a post-effective amendment to the registration statement of which this prospectus is a part or in filings we make with the SEC under the Exchange Act that are incorporated by reference into this prospectus. Such selling stockholders may include (i) certain of our significant stockholders, including investment funds affiliated with Vivo Ventures, LLC (“Vivo Ventures”), CNF Investments II, LLC (“CNF Investments”) and/or Morgan Stanley (“Morgan Stanley”), and (ii) certain of our executive officers and directors.

All of the common stock to be offered by selling stockholders under the registration statement of which this prospectus is a part is issued and outstanding as of the date of the filing of the registration statement of which this prospectus is a part. Selling stockholders shall not sell any of our common stock pursuant to this prospectus until we have identified such selling stockholders in a subsequent prospectus supplement. However, selling stockholders may sell or transfer all or a portion of their common stock pursuant to any available exemption from the registration requirements of the Securities Act. The selling stockholders originally acquired the shares of our common stock included in this prospectus through (i) a private placement of our ordinary shares to one of our founding investors in April 2006, (ii) private placements of our Series A preferred stock in March 2007, September 2007, August 2008 and May 2009, (iii) the grant of restricted ordinary shares in April 2006 and March 2007 under our 2007 Global Share Plan and (iv) the exercise of stock options for ordinary shares in February 2011, which options were originally granted in August 2008 and December 2009 under our 2007 Global Share Plan. All of the ordinary shares and Series A preferred stock referenced in the foregoing sentence were converted into shares of our common stock in connection with our reincorporation into a Delaware corporation at the time of our initial public offering in April 2011.

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PLAN OF DISTRIBUTION

We are registering 9,000,000 shares of our common stock for possible sale by us and an additional 15,052,223 shares of our common stock for possible sale by selling stockholders. Unless the context otherwise requires, as used in this prospectus, “selling stockholders” includes the selling stockholders named in any prospectus supplement, in a post-effective amendment to the registration statement of which this prospectus is a part or in filings we make with the SEC under the Exchange Act that are incorporated by reference into this prospectus and donees, pledgees, transferees or other successors-in-interest selling shares received from such selling stockholders as a gift, pledge, partnership distribution or other transfer after the date of the applicable prospectus supplement, post-effective amendment or Exchange Act report.

We and/or selling stockholders may offer and sell all or a portion of the shares covered by this prospectus from time to time, in one or more or any combination of the following transactions:

• on the NASDAQ Global Market, in the over-the-counter market or on any other national securities exchange on which our shares are listed or traded;

• in privately negotiated transactions;

• in underwritten transactions;

• in a block trade in which a broker-dealer will attempt to sell the offered shares as agent but may position and resell a portion of the block as principal to facilitate the transaction;

• through purchases by a broker-dealer as principal and resale by the broker-dealer for its account;

• in ordinary brokerage transactions and transactions in which the broker solicits purchasers; and

• through the writing of options (including put or call options), whether the options are listed on an options exchange or otherwise.

We and/or selling stockholders may sell the shares at prices then prevailing or related to the then current market price or at negotiated prices. The offering price of the shares from time to time will be determined by us and/or selling stockholders, as applicable, and, at the time of the determination, may be higher or lower than the market price of our common stock on the NASDAQ Global Market or any other exchange or market.

The shares may be sold directly or through broker-dealers acting as principal or agent, or pursuant to a distribution by one or more underwriters on a firm commitment or best-efforts basis. We and/or selling stockholders may also enter into hedging transactions with broker-dealers. In connection with such transactions, broker-dealers of other financial institutions may engage in short sales of our common stock in the course of hedging the positions they assume with us or selling stockholders, as applicable. We and/or selling stockholders may also enter into options or other transactions with broker-dealers or other financial institutions which require the delivery to such broker-dealer or other financial institution of shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction). In connection with an underwritten offering, underwriters or agents may receive compensation in the form of discounts, concessions or commissions from us or selling stockholders, as applicable, or from purchasers of the offered shares for whom they may act as agents. In addition, underwriters may sell the shares to or through dealers, and those dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agents. Any underwriters, dealers or agents participating in a distribution of the shares may be deemed to be “underwriters” within the meaning of the Securities Act, and any profit on the sale of the shares and any commissions received by broker-dealers may be deemed to be underwriting commissions under the Securities Act.

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We and/or selling stockholders may agree to indemnify an underwriter, broker-dealer or agent against certain liabilities related to the selling of the common stock, including liabilities arising under the Securities Act.

We will bear a portion of the expenses of the offering of common stock, except that selling stockholders will pay any applicable underwriting fees, discounts or commissions and certain transfer taxes with respect to their shares of common stock.

We have not entered into any agreements, understandings or arrangements with any underwriters or broker-dealers regarding the sale of shares. Upon entering into, or upon notification by selling stockholders that they have entered into, any material arrangement with an underwriter or broker-dealer for the sale of shares through a block trade, special offering, exchange distribution, secondary distribution or a purchase by an underwriter or broker-dealer, we will file a supplement to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, disclosing certain material information, including:

• the name of the applicable seller;

• the number of shares being offered;

• the terms of the offering;

• the names of the participating underwriters, broker-dealers or agents;

• any discounts, commissions or other compensation paid to underwriters or broker-dealers and any discounts, commissions or concessions allowed or reallowed or paid by any underwriters to dealers;

• the public offering price; and

• other material terms of the offering.

We and any selling stockholders are subject to the applicable provisions of the Exchange Act and the rules and regulations under the Exchange Act, including Regulation M. This regulation may limit the timing of purchases and sales of any of the shares of common stock offered pursuant to this prospectus. The anti-manipulation rules under the Exchange Act may apply to sales of shares in the market and to the activities of us, any selling stockholders and their affiliates.

To the extent required, this prospectus may be amended and/or supplemented from time to time to describe a specific plan of distribution. Instead of selling the shares of common stock under this prospectus, we and/or selling stockholders may sell the shares of common stock in compliance with the provisions of Rule 144 under the Securities Act, if available, or pursuant to other available exemptions from the registration requirements of the Securities Act.

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LEGAL MATTERS

The validity of the common stock offered hereby will be passed upon for us by Kirkland & Ellis LLP, Chicago, Illinois.

EXPERTS

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements and schedule included in our Annual Report on Form 10-K for the year ended December 31, 2011, as set forth in their report, which is incorporated by reference in this prospectus and elsewhere in the registration statement. Our financial statements and schedule are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

Ernst & Young Hua Ming, LLP, independent registered public accounting firm, has audited the financial statements of Kanghong Sagent (Chengdu) Pharmaceutical Co., Ltd., included in our Annual Report on Form 10-K for the year ended December 31, 2011, as set forth in their report (which contains an explanatory paragraph describing conditions that raise substantial doubt about the Kanghong Sagent (Chengdu) Pharmaceutical Co., Ltd.’s ability to continue as a going concern as described in Note 1 to the financial statements), which is incorporated by reference in this prospectus and elsewhere in the registration statement. The financial statements of Kanghong Sagent (Chengdu) Pharmaceutical Co., Ltd. are incorporated by reference in reliance on Ernst  & Young Hua Ming’s report, given on their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the common stock offered by this prospectus. This prospectus, which is a part of the registration statement, does not contain all of the information set forth in the registration statement or the exhibits and schedules filed therewith. For further information with respect to us and the common stock offered by this prospectus, please see the registration statement and the exhibits filed with the registration statement. Statements contained in this prospectus regarding the contents of any contract or any other document that is filed as an exhibit to the registration statement are not necessarily complete, and each such statement is qualified in all respects by reference to the full text of such contract or other document filed as an exhibit to the registration statement. A copy of the registration statement and the exhibits filed with the registration statement may be inspected without charge at the Public Reference Room maintained by the SEC, located at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for more information about the operation of the Public Reference Room. The SEC also maintains an Internet website that contains reports, proxy and information statements and other information regarding registrants that file electronically with the SEC. The address of the website is http://www.sec.gov.

We are subject to the information and periodic reporting requirements of the Exchange Act, and, in accordance therewith, we file periodic reports, proxy statements and other information with the SEC. Such periodic reports, proxy statements and other information are available for inspection and copying at the Public Reference Room and website of the SEC referred to above. We maintain a website at http://www. sagentpharma.com. You may access our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and amendments to those reports filed pursuant to Sections 13(a) or 15(d) of the Exchange Act with the SEC free of charge at our website as soon as reasonably practicable after such material is electronically filed with, or furnished to, the SEC. Our website and the information contained on that site, or connected to that site, are not incorporated into and are not a part of this prospectus, and you should not consider the contents of our website in making an investment decision with respect to our common stock.

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INCORPORATION BY REFERENCE OF CERTAIN DOCUMENTS

We are “incorporating by reference” specified documents that we file with the SEC, which means that we can disclose important information to you by referring you to those documents that are considered part of this prospectus. Later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference into this prospectus the documents listed below and any future filings (other than pursuant to Items 2.02 and 7.01 of a Current Report on Form 8-K) made with the SEC (other than any portion of such filings that are furnished under applicable SEC rules rather than filed) under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act, including filings made on or after the date hereof:

• our Annual Report on Form 10-K for the fiscal year ended December 31, 2011 filed with the SEC on March 29, 2012;

• our Quarterly Reports on Form 10-Q for the fiscal quarters ended March 31, 2012, June 30, 2012 and September 30, 2012 filed with the SEC on May 10, 2012, August 9, 2012 and November 8, 2012, respectively;

• our Current Reports on Form 8-K filed with the SEC on February 16, 2012, March 12, 2012, April 16, 2012, May 31, 2012, September 6, 2012 and November 8, 2012; and

• the description of our capital stock, $0.01 par value per share, included under the caption “Description of Capital Stock” in the Prospectus forming a part of our Registration Statement on Form S-1, initially filed with the SEC on December 6, 2010 (Registration No. 333-170979), including exhibits, and as amended, which description has been incorporated by reference in Item 1 of our Registration Statement on Form 8-A filed with the SEC on April 15, 2011 (File No. 001-35144).

Any statement contained in a document incorporated or deemed to be incorporated by reference into this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. Our Commission File Number is 001-35144.

Our filings with the SEC, including our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and amendments to those reports, are available free of charge on our website at http://www.sagentpharma.com as soon as reasonably practicable after they are filed with, or furnished to, the SEC. Our website and the information contained on that site, or connected to that site, are not incorporated into and are not a part of this prospectus. You may also obtain a copy of these filings at no cost by writing or telephoning us at the office of our Corporate Secretary, c/o Sagent Pharmaceuticals, Inc., 1901 North Roselle Road, Suite 700, Schaumburg, Illinois 60195, (847) 908-1600.

Except for the documents incorporated by reference as noted above, we do not intend to incorporate into this prospectus any of the information included on our website.

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

The following table sets forth all estimated expenses to be paid solely by us in connection with the sale of the securities being registered hereunder.

SEC registration fee	$	52,935
Legal fees and expenses		*
Accounting fees and expenses		*
Printing fees and expenses		*
Miscellaneous expenses		*
Total	$	*

* These fees are calculated based upon the number of issuances in applicable offerings and the amount of securities offered and, accordingly, cannot be estimated at this time.

Item 15. Indemnification of Directors and Officers

We are incorporated under the laws of the State of Delaware. Section 102(b)(7) of the Delaware General Corporation Law (the “DGCL”) allows a corporation to provide in its certificate of incorporation that a director of the corporation will not be personally liable to the corporation or its stockholders for monetary damages for breach of fiduciary duty as a director, except where the director breached the duty of loyalty, failed to act in good faith, engaged in intentional misconduct or knowingly violated a law, authorized the payment of a dividend or approved a stock repurchase in violation of Delaware corporate law or obtained an improper personal benefit. Our amended and restated certificate of incorporation provides for this limitation of liability.

Section 145 of the DGCL (“Section 145”) provides that a Delaware corporation may indemnify any person who was, is or is threatened to be made, party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of such corporation), by reason of the fact that such person is or was an officer, director, employee or agent of such corporation or is or was serving at the request of such corporation as a director, officer, employee or agent of another corporation or enterprise. The indemnity may include expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with such action, suit or proceeding, provided such person acted in good faith and in a manner he reasonably believed to be in or not opposed to the corporation’s best interests and, with respect to any criminal action or proceeding, had no reasonable cause to believe that his or her conduct was illegal. A Delaware corporation may indemnify any persons who are, were or are a party to any threatened, pending or completed action or suit by or in the right of the corporation by reason of the fact that such person is or was a director, officer, employee or agent of another corporation or enterprise. The indemnity may include expenses (including attorneys’ fees) actually and reasonably incurred by such person in connection with the defense or settlement of such action or suit, provided such person acted in good faith and in a manner he reasonably believed to be in or not opposed to the corporation’s best interests, provided that no indemnification is permitted without judicial approval if the officer, director, employee or agent is adjudged to be liable to the corporation. Where an officer or director is successful on the merits or otherwise in the defense of any action referred to above, the corporation must indemnify him against the expenses which such officer or director has actually and reasonably incurred.

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Section 145 further authorizes a corporation to purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation or enterprise, against any liability asserted against him and incurred by him in any such capacity, or arising out of his or her status as such, whether or not the corporation would otherwise have the power to indemnify him under Section 145.

Our certificate of incorporation provides that we must indemnify our directors and officers to the fullest extent authorized by the DGCL and must also pay expenses incurred in defending any such proceeding in advance of its final disposition upon delivery of an undertaking, by or on behalf of an indemnified person, to repay all amounts so advanced if it should be determined ultimately that such person is not entitled to be indemnified under this section or otherwise.

The indemnification rights set forth above shall not be exclusive of any other right which an indemnified person may have or hereafter acquire under any statute, provision of our certificate of incorporation, our bylaws, agreement, vote of stockholders or disinterested directors or otherwise.

We maintain standard policies of insurance that provide coverage (1) to our directors and officers against loss rising from claims made by reason of breach of duty or other wrongful act and (2) to us with respect to indemnification payments that we may make to such directors and officers.

In addition, a proposed form of purchase agreement or underwriting agreement filed as an exhibit in connection with an underwritten offering of the shares offered hereunder may provide for indemnification to our directors and officers by the underwriters against certain liabilities.

Item 16. Exhibits

The list of exhibits in the Exhibit Index to this registration statement is incorporated herein by reference.

Item 17. Undertakings

(a) The undersigned registrant hereby undertakes:

1. To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement.

Provided, however, that paragraphs (a)(1)(i), (ii) and (iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in this registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of this registration statement.

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2. That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

3. To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

4. That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

5. That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities: The undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

6. That, for purposes of determining any liability under the Securities Act of 1933, the information omitted from the form of prospectus filed as part of this registration statement in reliance upon Rule 430A and contained in a form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act shall be deemed to be part of this registration statement as of the time it was declared effective.

7. That, for the purpose of determining any liability under the Securities Act of 1933, each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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(b) The undersigned registrant hereby undertakes that for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the city of Schaumburg, State of Illinois, on January 25, 2013.

SAGENT PHARMACEUTICALS, INC.
By:	/s/ Jeffrey M. Yordon
Name: Jeffrey M. Yordon
Title: President and Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, this Amendment No. 1 to registration statement has been signed by the following persons in the capacities and on the dates indicated.

/s/ Jeffrey M. Yordon Jeffrey M. Yordon	President and Chief Executive Officer and Director (principal executive officer)	January 25, 2013
* Jonathon M. Singer	Executive Vice President and Chief Financial Officer (principal financial officer)	January 25, 2013
* Jeffrey W. Greve	Vice President, Controller (principal accounting officer)	January 25, 2013
* Mary Taylor Behrens	Director	January 25, 2013
* Anthony Krizman	Director	January 25, 2013
* Robert Flanagan	Director	January 25, 2013
* Frank Kung, Ph.D	Director	January 25, 2013

* The undersigned, by signing his name hereto, does sign and execute this Amendment No. 1 to registration statement pursuant to the Power of Attorney executed by the above-named persons and previously filed with the Securities and Exchange Commission on behalf of such persons.

/s/ Jeffrey M. Yordon

Jeffrey M. Yordon, as Attorney-in-Fact

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EXHIBIT INDEX

1.1*	Form of Underwriting Agreement
3.1	Certificate of Incorporation of Sagent Pharmaceuticals, Inc. (incorporated by reference to Exhibit 3.3 in the Company’s Registration Statement on Form S-1, as amended (File No. 333-170979)).
3.2	Bylaws of Sagent Pharmaceuticals, Inc. (incorporated by reference to Exhibit 3.4 in the Company’s Registration Statement on Form S-1, as amended (File No. 333-170979)).
4.1	Specimen Common Stock Certificate (incorporated by reference to Exhibit 4.1 in the Company’s Registration Statement on Form S-1, as amended (File No. 333-170979)).
4.2	Fourth Amended and Restated Members Agreement, dated as of September 3, 2010, by and among the registrant and certain investors named therein (incorporated by reference to Exhibit 10.14 in the Company’s Registration Statement on Form S-1, as amended (File No. 333-170979)).
5.1**	Opinion of Kirkland & Ellis LLP
23.1	Consent of Ernst & Young LLP, independent registered public accounting firm
23.2	Consent of Ernst & Young Hua Ming, independent registered public accounting firm
23.3**	Consent of Kirkland & Ellis LLP (included in Exhibit 5.1)
24.1**	Powers of Attorney (included on signature pages of this Registration Statement)

* To be filed, if necessary, after effectiveness of this registration statement by an amendment to the registration statement or incorporated by reference to a Current Report on Form 8-K filed in connection with an underwritten offering of the shares offered hereunder.

**Previously filed.

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