Catalyst Pharmaceuticals (CPRX) 10-K 2016 FY Annual report

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We have issued our reports dated March 15, 2017, with respect to the financial statements and internal control over financial reporting included in the Annual Report of Catalyst Pharmaceuticals, Inc. on Form 10-K for the year ended December 31, 2016. We consent to the incorporation by reference of said reports in the Registration Statements of Catalyst Pharmaceuticals, Inc. on Form S-3 as Post-Effective Amendment No. 6 to Form S-1 (File No. 333-180617), Forms S-8 (File No. 333-151367, File No. 333-183329, and File No. 333-198119), and Forms S-3 (File No. 333-170945, File No. 333-190996, File No. 333-193699, and File No. 333-215315).

/s/ GRANT THORNTON LLP                

Miami, Florida

March 15, 2017