How we grade evidence
Every peptide in the library gets one of four levels. Here's what each one means.
FDA-approved drug
FDA-approved drugApproved by the FDA for specific uses, backed by large human clinical trials. Prescription only.
In the library: Semaglutide, Tirzepatide, Tesamorelin, PT-141
Human clinical trials
Human clinical trialsStudied in controlled human trials, but not FDA-approved for the uses people commonly discuss.
In the library: Retatrutide, Cagrilintide, Sermorelin, Thymosin Alpha-1, AOD-9604
Early human research
Early human researchSmall or early-stage human studies. Promising signals, far from settled.
In the library: CJC-1295, Ipamorelin, GHK-Cu, Selank, Semax, Kisspeptin
Mostly animal research
Mostly animal researchMost published evidence comes from cell and animal studies. Human data is limited or absent.
In the library: BPC-157, TB-500, Epitalon, MOTS-c
Why animal research isn't enough
Animal studies are where most medicines start, and they're valuable. But many results in rodents never carry over to people, and side effects that matter in humans can be missed. Until a peptide is tested in well-designed human trials, its safety and effectiveness in people are unknown.
Where our sources come from
We base entries on published research and public regulatory information. Each peptide page links to its research on PubMed, the U.S. National Library of Medicine database, so you can check it yourself.