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Reference information only. Therapept does not sell peptides and does not provide medical advice.Research-use notice

Therapept

Cyclic heptapeptide

Melanotan II

A cyclic melanocortin receptor agonist with no approved drug product. It is structurally very close to bremelanotide, differing at the C-terminus.

Also listed as: MT-II, MTII

Chemical identity

Compound class
Cyclic heptapeptide; non-selective melanocortin receptor agonist (alpha-MSH analogue)
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Molecular formula
C50H69N15O9
Molecular weight
1024.2 g/mol
CAS number
121062-08-6
PubChem CID
92432
Research categories
Melanocortin analogues

United States regulatory status

No FDA-approved product

  • No approved drug product exists in Drugs@FDA.
  • Listed on FDA's table of bulk substances nominated for compounding and withdrawn by the nominator.
  • FDA's published entry references case reports of serious adverse events, including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism.
  • Not named on the WADA 2026 Prohibited List.

Regulatory status describes how a substance is classified. It is not a safety assessment, and it says nothing about the quality of any particular material.

Sources

  1. PubChem CID 92432
  2. FDA — Certain bulk drug substances for use in compounding may present significant safety risks

Last reviewed 3 September 2026 · Compiled by Therapept Editorial · How these records are built