What is PT-141, and what is it studied for?

What is the structure of PT-141?

Seven residues closed into a ring by a lactam bridge between an aspartate side chain and a lysine side chain, with a D-phenylalanine and a norleucine as in melanotan-1, and a free C-terminal carboxyl where melanotan-2 has an amide. That one-dalton difference, plus the ring, is what the certificate's identity line resolves. The D-residue is invisible to mass spectrometry.

Identifier	Value
Molecular formula	C50H68N14O10
Molecular weight	1025.2 g/mol
Residues	7
CAS number	189691-06-3
PubChem CID	9941379
Current lot	PT141-0803

How is PT-141 thought to work?

Agonist at MC4R and MC3R, G-protein-coupled receptors expressed centrally, with lower activity at MC1R than melanotan-1. Molinoff and colleagues described its receptor profile in 2003. The approved product's trials, reported by Kingsberg and colleagues in 2019, concern a regulated pharmaceutical and are context only.

Which research areas use PT-141?

Area	Typical models and endpoints
MC4R and MC3R pharmacology	Binding and cAMP assays in cells expressing melanocortin receptors.
Receptor selectivity	Comparison with melanotan-1, melanotan-2 and alpha-MSH across the receptor family.
Central melanocortin signalling	Rodent models of hypothalamic circuits.
Cyclic peptide chemistry	A lactam-bridged peptide for stability and fragmentation studies.

What does the published literature show?

Molinoff et al. (Annals of the New York Academy of Sciences, 2003) described PT-141's melanocortin pharmacology. Clinical development led to FDA approval in June 2019; Kingsberg et al. (Obstetrics and Gynecology, 2019) reported the phase 3 trials of the pharmaceutical product. Nothing about the material sold here is drawn from those trials; research use is in-vitro and preclinical.

How is PT-141 handled in the laboratory?

Supplied here lyophilized; the catalogue also lists a solution format, which the PT-141 solution post explains. Dissolves in water. No methionine (norleucine replaces it); a tryptophan is light-sensitive, so protect solutions. Store lyophilized at minus 20 °C; aliquot and freeze. The concentration table covers volumes and syringe units; the storage guide covers stability by compound class.

What does the current certificate show?

Lot PT141-0803 tested at 99.85% purity by RP-HPLC (214 nm), identity confirmed by LC-MS/MS, endotoxin <0.05 EU/mL. The certificate is in the COA library and the lot number on the vial matches it. Sold as 10 mg per vial at $60, for laboratory research only.

Certificate history for PT-141

Every certificate the library holds for this compound, newest first. A replaced lot stays listed so the history can be read; the certificate dataset reads all 114 together.

Frequently asked questions

References

1. Molinoff PB, Shadiack AM, Earle D, Diamond LE, Quon CY. PT-141: a melanocortin agonist for the treatment of sexual dysfunction. Ann N Y Acad Sci. 2003;994:96-102.
2. Kingsberg SA, Clayton AH, Portman D, et al. Bremelanotide for the treatment of hypoactive sexual desire disorder in women: two randomized phase 3 trials. Obstet Gynecol. 2019;134(5):899-908.
3. PubChem CID 9941379, Bremelanotide. National Library of Medicine. Read 2 October 2026.

Clinical results cited above describe regulated trials of pharmaceutical products and are given as context for research interest only. Nothing on this page describes or recommends use of the material sold here in humans or animals.