How this works
We grade the evidence behind marketed peptides and show you the papers. We sell nothing and recommend nothing.
The grades
A–F, by the strength of human evidence for the marketed use:
- A — approved; multiple large RCTs
- B — one strong human trial, or narrower approval
- C — small or preliminary human data
- D — preclinical only; no human efficacy
- F — tried in humans and failed, or harmful
- UNKNOWN — too little to grade
Borderline calls round down. Nearly half the catalog is D or UNKNOWN; that's the literature, not pessimism.
The sources
Open-access medical literature, never vendor claims or forums. Where the literature is open-access, each grade links to the dated papers; where the only evidence is non-English or preclinical, the rationale names what exists.
The stance
No vendor ties, no buy links, no doses, no protocols. We rate how proven a claim is; the decision is yours.
Not medical advice
PurityGap is an independent educational resource; it has no affiliation with any seller or manufacturer and does not recommend taking, dosing, or sourcing any compound. Any decision about a drug belongs with a licensed clinician.