As filed with the Securities and Exchange Commission on August 7, 2023

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)

Thane Wettig

Interim 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:

Nancy Wojtas

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. ☐

EXPLANATORY NOTE

FibroGen, Inc. (the “Registrant”) is filing this Registration Statement on Form S-8 for the purpose of registering (a) an additional 3,766,643 shares of its common stock, par value $0.01 per share (the “Common Stock”), issuable to eligible persons under the Registrant’s 2014 Equity Incentive Plan (“2014 EIP”), and (b) an additional 941,660 shares of its Common Stock, issuable to eligible persons under the Registrant’s 2014 Employee Stock Purchase Plan (“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 with the Securities and Exchange Commission (the “Commission”) filed on November 18, 2014 (File No. 333-200348), September 27, 2016 (File No. 333-213816), March 1, 2017 (File No. 333-216369), August 9, 2019 (File No. 333-233204), August 9, 2021 (File No. 333-258655), and August 8, 2022 (File No. 333-266667) (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.

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 7th day of August, 2023.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Thane Wettig and Juan Graham, 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.