v3.26.1
Document and Entity Information
Jun. 08, 2026
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0001691082
Document Type 8-K
Document Period End Date Jun. 08, 2026
Entity Registrant Name LB Pharmaceuticals Inc
Entity Incorporation State Country Code DE
Entity File Number 001-42831
Entity Tax Identification Number 81-1854347
Entity Address, Address Line One One Pennsylvania Plaza
Entity Address, Address Line Two Suite 1025
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10119
City Area Code (212)
Local Phone Number 605-0300
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Stock, $0.0001 par value per share
Trading Symbol LBRX
Security Exchange Name NASDAQ
Entity Emerging Growth Company true
Entity Ex Transition Period false