Peptide comparison
Bremelanotide (PT-141) grew out of research on Melanotan II and its structure is practically the same: an identical cyclic heptapeptide except at the tail end. That small difference, together with a complete clinical development in one case and none in the other, sets them completely apart.
Compare mechanism, class, receptors and evidence. All compounds are offered with ≥99% purity verified by HPLC and a batch COA.
| PT-141 (bremelanotide) | Melanotan II | |
|---|---|---|
| Structure | Cyclic heptapeptide with an acid end (–OH) | Cyclic heptapeptide with an amidated end (–NH₂) |
| Main receptors | MC4R and MC3R | Several: MC1R, MC3R, MC4R, MC5R |
| Effect on pigmentation | Smaller | Marked (via MC1R) |
| Research focus | Sexual function (central pathway) | Pigmentation and sexual function |
| Clinical development | Complete | No formal clinical development |
| Status | FDA-approved for a specific indication | Not approved; warnings from several health agencies |
Melanotan II is a cyclic α-MSH analogue that activates almost all melanocortin receptors. That is why its profile is broad: it produces pigmentation through MC1R and effects on sexual function through central nervous system receptors. It never completed clinical development and several health agencies have warned about its use outside controlled studies.
Bremelanotide (PT-141) is, chemically, the same ring with the C-terminus as an acid instead of an amide. Its development focused on the central pathway (MC4R) and it completed clinical trials through to FDA approval for hypoactive sexual desire disorder in premenopausal women. It is a good example of how a structural detail and, above all, a clinical programme completely change a molecule's status.
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No, although they are almost identical: they share the same peptide ring and differ only at the C-terminus (acid in PT-141, amide in Melanotan II). Their receptor selectivity and regulatory status are different.
Because Melanotan II strongly activates the MC1R receptor on melanocytes, whereas PT-141 acts mainly on MC4R and MC3R in the central nervous system.
Bremelanotide is FDA-approved as a medicine for a specific indication. Melanotan II is not approved in any country. The material in this catalogue is for research use only.
Purity ≥99% verificada por HPLC and batch COA.
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