About This Reference

What this reference covers

Definitive Peptides was built to do one job well: give a precise, citation-anchored account of five widely searched research peptides — BPC-157, semaglutide, thymosin alpha-1, CJC-1295 and MOTS-c — that between them span tissue repair, metabolic disease, immune modulation, growth-hormone signaling and mitochondrial metabolism. They were chosen deliberately for how differently they sit in the evidence landscape, not for how similar they are. That range is the reference's organizing idea: reading five compounds with genuinely different mechanisms and genuinely different regulatory histories side by side shows what "well-studied" actually means for a peptide, rather than assuming it.

Each compound gets its own page covering mechanism, cited findings, community-reported effects (always labeled anecdotal), and cited safety cautions. A comparison page and an FAQ page draw the same material together from two other angles. One shared reference list, gathered from the peer-reviewed and pre-clinical literature, anchors every numbered citation across the site.

How this reference is compiled

Every factual claim on this site traces to a source on the references page — a peer-reviewed journal article, a clinical-trial publication, or a formal regulatory document, each with a DOI or PubMed identifier where one exists. Findings are reported in the species and population they were actually studied in: a result from a rodent study is described as a rodent finding, not extrapolated to people, and a phase-2 trial result is never presented as though it were phase-3 confirmed. Where a compound's human evidence is thin — as with BPC-157, CJC-1295 and especially MOTS-c — this reference says so directly rather than papering over the gap with animal data dressed up as human-relevant.

Anecdotal reports from research-use and patient communities appear on every compound page, because they are part of the honest picture of how a compound is actually being used and discussed. They are always clearly separated from the cited clinical evidence, always labeled anecdotal, and never attached to a recommended dose.

Where this reference stops

Definitive Peptides is a reading desk, not a pharmacy, a clinic, or a supplier of any kind. Nothing here is sold, sourced, or brokered, and no dose, schedule, or route is recommended for any individual, on any page. Two of the five compounds covered here — semaglutide, and thymosin alpha-1 outside the United States — are approved medicines available only through a licensed prescriber; the other three are unapproved research chemicals with real, documented gaps in their human evidence. This site's role is to make those distinctions legible, not to resolve them into a recommendation. Anyone considering any of these compounds for any purpose should take that decision to a licensed clinician working from their own full medical history, not to a research digest. Corrections, citation updates, or newly published studies can be sent through the contact page.