As filed with the Securities and Exchange Commission on August 9, 2021

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

FibroGen, Inc.

(Exact name of registrant as specified in its charter)

409 Illinois St.

San Francisco, CA 94158

(415) 978-1200

(Address of principal executive offices)

2014 Equity Incentive Plan

2014 Employee Stock Purchase Plan

(Full titles of the plans)

Enrique Conterno

Chief Executive Officer

FibroGen, Inc.

409 Illinois Street

San Francisco, CA 94158

(415) 978-1200

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

Copies to:

Michael E. Tenta

Cooley LLP

3175 Hanover Street

Palo Alto, CA 94304

(650) 843-5000

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. (Check one):

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

EXPLANATORY NOTE

FibroGen, Inc. (the “Registrant”) is filing this Registration Statement on Form S-8 for the purpose of registering (a) an additional 7,163,924 shares of its common stock, par value $0.01 per share (the “Common Stock”), issuable to eligible persons under the 2014 EIP, and (b) an additional 1,790,980 shares of its Common Stock, issuable to eligible persons under the 2014 ESPP, in each case which Common Stock is in addition to the shares of Common Stock registered on the Registrant’s Forms S-8 filed on November 18, 2014 (File No. 333-200348), September 27, 2016 (File No. 333-213816), March 1, 2017 (File No. 333-216369), and August 9, 2019 (File No. 333-233204) (the “Prior Registration Statements”).

INCORPORATION BY REFERENCE OF CONTENTS OF

REGISTRATION STATEMENT ON FORM S-8

The following documents filed by the Registrant with the Commission are incorporated by reference into this Registration Statement:

Pursuant to General Instruction E to Form S-8, the contents of the Prior Registration Statements are incorporated herein by reference and made a part hereof.

All other reports and documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended (other than Current Reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits furnished on such form that relate to such items) on or after the date of this Registration Statement and prior to the filing of a post-effective amendment to this Registration Statement which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference herein and to be a part of this Registration Statement from the date of the filing of such reports and documents. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any subsequently filed document that also is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of San Francisco, State of California, on this 9th day of August, 2021.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Enrique Conterno and Pat Cotroneo, jointly and severally, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement on Form S-8, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his substitutes or substitute, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

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Exhibit 5.1

Michael E. Tenta

+1 650 843 5636

mtenta@cooley.com

August 9, 2021

FibroGen, Inc.

409 Illinois Street

San Francisco, CA 94158

Ladies and Gentlemen:

We have acted as counsel to FibroGen, Inc., a Delaware corporation (the “Company”) in connection with the filing of a Registration Statement on Form S-8 (the “Registration Statement”) with the U.S. Securities and Exchange Commission covering the offering of up to an aggregate of 8,954,904 shares (the “Shares”) of the Company’s Common Stock, par value $0.01 per share (“Common Stock”), including (a) 7,163,924 shares of Common Stock pursuant to the Company’s 2014 Equity Incentive Plan (the “2014 Plan”) and (b) 1,790,980 shares of Common Stock pursuant to the Company’s 2014 Employee Stock Purchase Plan (together with the 2014 Plan, the “Plans”).

In connection with this opinion, we have examined and relied upon (a) the Registration Statement and related prospectus, (b) the Plans, (c) the Company’s Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws, each as currently in effect and (d) originals or copies certified to our satisfaction of such other records, documents, certificates, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies, the accuracy, completeness and authenticity of certificates of public officials, and the due authorization, execution and delivery of all documents by all persons other than by the Company where authorization, execution and delivery are prerequisites to the effectiveness thereof. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not independently verified such matters.

Our opinion is expressed only with respect to the General Corporation Law of the State of Delaware. We express no opinion to the extent that any other laws are applicable to the subject matter hereof and express no opinion and provide no assurance as to compliance with any federal or state securities law, rule or regulation.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares, when sold and issued in accordance with the Plans, and the Registration Statement and related prospectus, will be validly issued, fully paid, and nonassessable (except as to shares issued pursuant to certain deferred payment arrangements, which will be fully paid and nonassessable when such deferred payments are made in full).

We consent to the filing of this opinion as an exhibit to the Registration Statement. Very truly yours,

Cooley LLP 3175 Hanover Street Palo Alto, CA 94304-1130

t: (650) 843-5000 f: (650) 849-7400 cooley.com

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of FibroGen, Inc. of our report dated March 1, 2021 relating to the consolidated financial statements and the effectiveness of internal control over financial reporting, which appears in FibroGen, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2020.