Exhibit 32.1

Certification Required by 18 U.S.C. Section 1350

(as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002)

I, Richard J. Daly as Principal Executive Officer of Catalyst Pharmaceuticals, Inc. (the Company), certify, pursuant to 18 U.S.C. Section 1350 (as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002), that to my knowledge:

1.the accompanying Quarterly Report on Form 10-Q of the Company for the quarterly period ended June 30, 2024 (the Report), filed with the U.S. Securities and Exchange Commission, fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2.the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: August 7, 2024	/s/ Richard J. Daly
	Richard J. Daly
	President and Chief Executive Officer
	(Principal Executive Officer)