Compounds / 8 things sold as peptides that are not peptides

Sold as peptides. Not peptides.

A peptide is a short chain of amino acids. Several products sold in the same catalogues, by the same clinics, under the same "peptide" heading are nothing of the kind. That matters for a practical reason rather than a pedantic one: a small molecule taken as a pill and an injected peptide behave differently in the body, are regulated differently, and are studied differently. Ibutamoren is routinely sold as a SARM, which it also is not.

None of this says these compounds do or do not work. It says the category label is wrong, and a wrong label is the first thing to check when a claim sounds confident.

An NNMT inhibitor, not a peptide. Widely sold for fat loss and longevity; zero registered human trials.

Thymus peptide extract

A calf-thymus extract sold as an immune and longevity peptide. Zero registered human trials in the registries we track.

FTPP · Prohibitin-TP01

Marketed for fat loss on the basis of primate studies. Zero registered human trials.

Ramatercept · ActRIIB-IgG1

A myostatin-pathway fusion protein whose clinical development stopped. Still sold as a muscle-building peptide.

A triple monoamine reuptake inhibitor rather than a peptide, despite being sold in peptide catalogues.

MK-677 · MK-0677 · LUM-201 · Nutrobal

A growth-hormone secretagogue, widely mislabelled as a SARM. Studied mostly for growth hormone deficiency rather than the uses it is sold for.

Tβ4 · TB4 full protein

The full protein, distinct from the TB-500 fragment sold online. Real research programme — mostly eye drops and wound healing.

Porcine brain peptide preparation

A porcine brain-derived preparation, not a single defined molecule. Studied largely for stroke and dementia rather than cognitive enhancement in healthy people.

—Read this

Why the label matters

Peptides are usually injected because stomach acid destroys them; small molecules are often oral. A vendor listing both under one heading is describing a shelf, not a class of molecule. We still track these because people encounter them as peptides — which is exactly why the distinction belongs somewhere.

See all 42 compounds →