EX-5.1


	2100 L STREET, NW	MORRISON FOERSTER LLP AUSTIN, BEIJING, BERLIN, BOSTON, BRUSSELS, DENVER, HONG KONG, LONDON, LOS ANGELES, MIAMI, NEW YORK, PALO ALTO, SAN DIEGO, SAN FRANCISCO, SHANGHAI, SINGAPORE, TOKYO, WASHINGTON, D.C.
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We are acting as counsel to Crinetics Pharmaceuticals, Inc., a Delaware corporation (the “Company”), in connection with its registration statement on Form S-8 (the “Registration Statement”), filed with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), relating to the proposed offering of up to 4,090,513 shares (the “Shares”) of the Company’s common stock, par value $0.001 per share, all of which Shares may be issued pursuant to awards under the Company’s 2018 Incentive Award Plan (the “2018 Plan”) and/or the Company’s 2018 Employee Stock Purchase Plan (the “ESPP”, and, together with the 2018 Plan, the “Plans”).

As counsel for the Company, we have examined originals or copies, certified or otherwise identified to our satisfaction, of such documents, corporate records, certificates of public officials and other instruments as we have deemed necessary for the purposes of rendering this opinion, and we are familiar with the proceedings taken and proposed to be taken by the Company in connection with the authorization, issuance and sale of the Shares. In our examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals and the conformity with the originals of all documents submitted to us as copies. For the purpose of the opinion rendered below, we have assumed that in connection with the issuance of the Shares, the Company will receive consideration in an amount not less than the aggregate par value of the Shares covered by each such issuance. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

The opinion expressed herein is limited to the General Corporation Law of the State of Delaware, the Delaware Constitution and reported judicial decisions interpreting those laws, each as currently in effect.

Based upon and subject to the foregoing, it is our opinion that following (i) effectiveness of the Registration Statement, (ii) issuance of the Shares pursuant to the terms

of the applicable Plan, and (iii) receipt by the Company of the consideration for the Shares specified in the applicable resolutions of the Board of Directors or a duly authorized committee thereof and the applicable Plan, the Shares will be validly issued, fully paid and nonassessable.

We consent to the use of this opinion as an exhibit to the Registration Statement, and we consent to the reference of our name wherever appearing in the Registration Statement and any amendments thereto. 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.