Exhibit 5.1

	12636 High Bluff Drive, Suite 400
	San Diego, California 92130-2071
	Tel: +1.858.523.5400    Fax: +1.858.523.5450
	www.lw.com
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January 7, 2013
Zogenix, Inc.
12400 High Bluff Drive, Suite 650
San Diego, California 92130

Re: Registration Statement on Form S-3

Ladies and Gentlemen:

We have acted as special counsel to Zogenix, Inc., a Delaware corporation (the “Company”), in connection with the filing on January 7, 2013, with the Securities and Exchange Commission (the “Commission”) of a registration statement on Form S-3 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Securities Act”), pertaining to the registration of the issuance of up to 15,784,200 shares (the “Shares”) of the Company’s common stock, par value $0.001 per share (the “Common Stock”), upon exercise of outstanding warrants (the “Warrants”). This opinion is being furnished in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement, the Prospectus or any Prospectus Supplement (both as herein defined) other than as expressly stated herein with respect to the issuance of the Shares.

You have provided us with a draft of the Registration Statement in the form in which it will be filed, which includes a base prospectus (the “Prospectus”). The Prospectus provides that it will be supplemented in the future by one or more supplements to the Prospectus (each, a “Prospectus Supplement”). The Registration Statement registers the offering by the Company of the Shares.

As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. We are opining herein as to the General Corporation Law of the State of Delaware, and we express no opinion with respect to any other laws.

January 7, 2013

Page 2

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, the issue and sale of the Shares in the manner contemplated by the Registration Statement and the Warrants have been duly authorized by all necessary corporate action of the Company, and, upon issuance, delivery and payment therefor in the manner contemplated by the Registration Statement and the Warrants, the Shares will be validly issued, fully paid and nonassessable.

We bring your attention to the fact that Latham & Watkins LLP and certain of the attorneys in this firm who have rendered, and will continue to render, legal services to the Company hold shares of Common Stock representing in the aggregate less than one percent of the Company’s Common Stock outstanding immediately prior to the filing of the Registration Statement.

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Securities Act. We consent to your filing this opinion as an exhibit to the Registration Statement and to the reference to our firm in the Prospectus under the heading “Legal Matters.” In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission thereunder.

Very truly yours,

/s/ Latham & Watkins LLP