v3.26.1
Cover
 12 Months Ended
Dec. 31, 2025
Document Information [Line Items]  
Document Type S-1
Entity Registrant Name Semnur Pharmaceuticals, Inc.
Entity Incorporation, State or Country Code DE
Entity Tax Identification Number 98-1659463
Entity Address, Address Line One 960 San Antonio Road
Entity Address, City or Town Palo Alto
Entity Address, State or Province CA
Entity Address, Postal Zip Code 94303
City Area Code 650
Local Phone Number 516-4310
Entity Filer Category Non-accelerated Filer
Entity Small Business true
Entity Emerging Growth Company true
Entity Ex Transition Period true
Entity Central Index Key 0001913577
Amendment Flag true
Entity Primary SIC Number 2836
Amendment Description EXPLANATORY NOTE This Post-Effective Amendment No. 1 (“Post-Effective Amendment No. 1”) to the Registration Statement on Form S-1 (File No. 333-290995) (the “Registration Statement”), as originally declared effective by the Securities and Exchange Commission (the “SEC”) on December 29, 2025, is being filed to include information contained in the Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025 filed with the SEC on February 27, 2026 and to update certain other information in the Registration Statement. The information included in this filing amends the Registration Statement and the prospectus contained therein. No additional securities are being registered under this Post-Effective Amendment No. 1. All applicable registration fees were paid at the time of the original filing of the Registration Statement on October 21, 2025.
Business Contact [Member]  
Document Information [Line Items]  
Contact Personnel Name Henry Ji
Entity Address, Address Line One 960 San Antonio Road
Entity Address, City or Town Palo Alto
Entity Address, State or Province CA
Entity Address, Postal Zip Code 94303
City Area Code 650
Local Phone Number 516-4310