the pentadecapeptide question that gets asked weekly, answered properly

Something I keep coming back to: the pentadecapeptide question that gets asked weekly, answered properly.

Bought small, tested identity first, and only then thought about anything else. That order felt right.

The three questions, kept separate, because this board runs them together constantly.

Identity: is this the sequence I ordered? Answered by mass spectrometry against a theoretical mass. Quantity: how much peptide is in the vial? Answered by net peptide content, not by area percent. Stability: what happens to it in solution over time? Answered by a stability statement with conditions attached, and almost never asked for.

A certificate that answers one of the three is common. One that answers all three is rare and worth choosing a supplier over. Nothing here is approved for human use in any case, so all three are questions about material rather than about anything else.

The evidence base, described honestly, which almost no summary of it does.

The published literature is overwhelmingly preclinical and largely in rodent models. The individual papers are generally more modest in their claims than the summaries that circulate. Human clinical trial evidence for the claims most often repeated in these threads is very limited.

That is not an argument that nothing is happening in the preclinical work — some of it is genuinely interesting. It is an argument that the distance between "this happened in a rodent model" and "this will happen in a person" is large, uncertain, and crossed silently in nearly every confident post on this board, including some of mine from two years ago.

Not medical advice, obviously, and nothing here is approved for human use. One person with a spreadsheet.