Analytical identity of BPC-157: a 15-mer with a simple mass

Analytical identity of BPC-157: a 15-mer with a simple mass Writing it up because I had to work it out twice and would rather nobody else did.

Comparing SURMOUNT-OSA (N Engl J Med, 2024) with STEP 2 (Lancet, 2021) and finding the comparison harder than it looks.

Different populations, different durations, different endpoints defined slightly differently, and in one case a different estimand. People compare the headline percentages anyway, including me until recently.

Is there a defensible way to put these side by side, or is the honest answer that there is not and we should stop?

the opening post is right about the mechanism and I think understates the practical bit.

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

BPC-157: the preclinical literature is extensive, mostly from a small number of research groups, and reports effects across a wide range of injury models. The breadth of reported effects is itself worth noting — a compound that improves outcomes in tendon, muscle, gut, nerve and bone through a single mechanism would be remarkable, and remarkable claims deserve proportionate scrutiny.

The distinction between "no evidence it works" and "evidence it does not work": we have the first for these compounds. That is genuinely different from the second and the distinction matters, but it also means treatment plans based on these compounds are being built on theoretical grounds, not empirical ones.

Two things before anyone answers the substance.

First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound.

post #5 answers the question as asked. The question underneath it is different.

Stability of BPC-157 in solution: what has been measured in published work covers specific formulations under specific conditions. Extrapolating to a reconstituted preparation in a different diluent at a different concentration is an extrapolation, acknowledged as one.

Why plausible mechanism is not evidence of effect: a mechanism that is chemically or biologically plausible can fail in practice for dozens of reasons — bioavailability, off-target effects, metabolism, clearance, or simply that the mechanism does not do what the theory predicts in a living system. Plausibility is necessary for hope but not sufficient for evidence.

Analytical identity of BPC-157: a 15-residue peptide with an unambiguous mass (≈1419.5 Da). Identity confirmation by LC-MS is trivially easy, which means there is no excuse for an unverified identity on this compound.