Description
PT-141 is a lactam-bridged cyclic peptide built on the core melanocortin pharmacophore, His-Phe-Arg-Trp, with a D-phenylalanine that locks the conformation receptors recognise.
PT-141 10 mg, a cyclic melanocortin agonist
Its ring is closed by an amide bond between the side chains of aspartate and lysine, and the N-terminus carries acetyl-norleucine. The C-terminus is a free acid, which is the structural difference between PT-141 and Melanotan II, whose C-terminus is amidated. That single change shifts the mass to 1025.2 g/mol and is easy to overlook when comparing the two.
In research it is used to probe melanocortin receptors, especially MC3R and MC4R, in binding and cAMP assays. Its cyclic structure makes it considerably more resistant to proteases than linear alpha-MSH analogues.
Compound identity and specification
| Compound | PT-141 (bremelanotide) |
|---|---|
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH |
| Molecular formula | C50H68N14O10 |
| Molecular mass | 1025.2 g/mol |
| CAS registry number | 189691-06-3 |
| PubChem | CID 9941379 |
| Vial content | 10 mg |
| Physical form | Lyophilised powder in a sealed vial |
| Analysis | Third-party HPLC and purity testing to a 99%+ specification; certificates are posted on our COAs page |
| Supplied for | Laboratory research use only |
Questions about PT-141 10mg
How does PT-141 differ from Melanotan II?
PT-141 ends in a free carboxylic acid; Melanotan II ends in an amide. The ring and core sequence are otherwise shared.
What holds the ring together?
A lactam bridge, an amide bond between the aspartate and lysine side chains.
Which receptors is PT-141 used to study?
Melanocortin receptors, most often MC3R and MC4R.
Research literature
Peer-reviewed studies involving this compound and its class. All findings listed are from in vitro, cell culture or animal models and are provided for scientific reference only. This product is supplied for laboratory research and is not approved for human consumption, clinical, or veterinary use.
- Suzuki S, et al. Anticancer Res. 2024;44(9):3875-3883. In human glioblastoma cell lines, measured survivin protein expression and cell death, blocked by melanocortin receptor antagonists and by survivin overexpression. Source · PMID 39197897
- Yuan XC, Tao YX Biomolecules. 2022;12(10):1407. Review cataloguing ligand pharmacology across the five melanocortin receptors, including approved melanocortin-receptor agonists. Source · PMID 36291616
Literature notes: Most primary literature on this compound reports clinical endpoints and is outside the scope of this reference list.
Certificates for our compounds are posted on the certificates of analysis page and matched to vials by cap and crimp colour. If the one for this product is not up yet, contact the order desk.
Related research compounds
Browse more compounds in Melanocortin Peptides, or view the full research peptide catalogue.
Background on the compound: PT-141, melanocortin selectivity and the lactam bridge — receptor subtype profile, how it differs from melanotan-II, and what to check on the certificate.
Supplied for laboratory research use only. Not for human or veterinary use.
