v3.25.3
Cover
 9 Months Ended
Sep. 30, 2025
Document Information [Line Items]  
Document Type S-1/A
Amendment Flag true
Entity Registrant Name Semnur Pharmaceuticals, Inc.
Entity Central Index Key 0001913577
Entity Incorporation, State or Country Code DE
Entity Primary SIC Number 2836
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
Amendment Description The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.
Business Contact [Member]  
Document Information [Line Items]  
Contact Personnel Name Jaisim Shah
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