BPC-157 is a synthetic peptide described as a fragment of a protein found in human gastric juice. A provenance that is itself disputed, since the parent protein has not been independently characterised.

It has an unusual profile in this compendium: a large preclinical literature reporting large, consistent effects across many different injury models, and essentially nothing in humans. Whether that pattern reflects a genuinely broad-acting compound or a narrow research network is the single most argued question about it, and the honest answer is that the published record cannot currently distinguish the two.

No mechanism is established. Several have been proposed from animal work, including upregulation of VEGF receptor 2 signalling and angiogenesis, modulation of nitric oxide pathways, effects on growth hormone receptor expression in tendon fibroblasts, and interaction with the gut-brain axis via dopaminergic and serotonergic systems.

These are hypotheses generated from the same body of work whose independence is in question, and they have not been independently replicated. A proposed mechanism is not a result, and this entry is a clean example of the difference.

Preclinical only. There is no completed randomised controlled trial in humans reporting results for any indication.

The animal literature is extensive, on the order of 180 published studies, and reports benefit across tendon, ligament, muscle, gut, and vascular injury models. The consistency and magnitude across such different models is atypical for a real biological effect and is more often a signature of shared methodology than of broad efficacy.

An oral formulation was investigated for inflammatory bowel disease in early human work more than a decade ago. No adequately powered results have been published since.

Anyone summarising this as "well studied" is doing something misleading with the word. It is extensively studied by a small number of people, which is not the same claim.

Human safety data is close to absent. Animal toxicology reports a wide therapeutic window, which is not a substitute for human data and is not reassuring on its own.

The unknowns that matter: no characterised long-term safety, no immunogenicity data, and a proposed pro-angiogenic mechanism that would be an active concern in anyone with an undiagnosed malignancy. The same mechanism that makes it interesting for healing would make it interesting for a tumour.

Material sold as research-use-only is not manufactured to pharmaceutical standards. Identity, purity, sterility, and endotoxin content are unverified unless someone verifies them, and a certificate of analysis from the seller is not verification.

Not approved for human use in any major jurisdiction. Sold as a research chemical. Prohibited in sport under the World Anti-Doping Agency's S0 category covering non-approved substances.

Regulatory status of the raw material and of compounding has moved repeatedly and differs sharply by jurisdiction. Any confident statement about legality is a statement about one country, usually made without saying so.