ATH (GLW)

ATH appears on peptide retailer catalogues, usually annotated with the sequence GLW, as a compound for healing and recovery. The three letters correspond to glycine, leucine and tryptophan in single-letter amino acid code, so the material is presumably a tripeptide with that sequence.

Searching the published literature returns nothing. There is no paper describing the synthesis or characterisation of Gly-Leu-Trp as a bioactive peptide, no receptor or binding data, no animal pharmacology, no pharmacokinetics and no clinical study. Search results for the sequence are incidental: the tripeptide appears as a fragment inside synthetic substrates built for assaying matrix metalloproteinases [1][2], which is a laboratory reagent context and tells us nothing about biological activity of the free peptide.

This is a different situation from a compound with weak evidence. BPC-157 has animal pharmacology that can be read and criticised; TB-500 has a characterised parent protein. Here there is no starting point at all. Without a published structure, purity standard or identifier, it is not even possible to say what relationship the material sold under this name bears to any characterised molecule.

Very short peptides also face a general pharmacological problem worth stating: a free tripeptide injected or swallowed is a substrate for the same peptidases that digest dietary protein, and in the absence of any published pharmacokinetic data there is no reason to assume it survives long enough to do anything.

This entry exists to record the absence of evidence. If pharmacology for this compound is ever published, it will be added here.

No mechanism has been published for ATH or for Gly-Leu-Trp as a bioactive peptide. It is marketed for tissue healing, but no target, receptor, binding study or signalling pathway has been reported for it in the literature.

There is no safety data of any kind: no toxicology, no animal study, no human exposure report. Nothing can be said about its safety because nothing has been published.

Two things can be said about the situation rather than the compound. First, an unidentified peptide from an unregulated supply chain carries the risks that grey-market peptide analyses have repeatedly documented - contents that do not match the label, and impurities from synthesis [3]. Second, the absence of published harm is not evidence of safety; it is evidence that nobody has looked.

No interaction data exist, and none can exist for a compound with no published pharmacology.