PT-141: 10MG

PT-141, known generically as bremelanotide, is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (alpha-MSH). It was first described in the literature in 2003, derived from Melanotan II - a synthetic melanocortin agonist originally investigated for tanning purposes. During clinical evaluation of Melanotan II, researchers observed significant increases in sexual behaviour, which prompted focused development of a more selective compound. Bremelanotide was synthesised specifically to retain melanocortin receptor activity relevant to sexual function while reducing the broader side effect profile of its predecessor.

Bremelanotide acts as a non-selective agonist at melanocortin receptors (MCR), with the following affinity order: MC1R, MC4R, MC3R, MC5R, MC2R. At therapeutic concentrations, MC1R and MC4R binding are most pharmacologically relevant. Neurons expressing MC4R are distributed widely throughout the central nervous system - including the medial preoptic area of the hypothalamus and other limbic regions implicated in sexual behaviour - providing the neuroanatomical basis for the compound's central mechanism.

A critical distinction: bremelanotide's mechanism operates centrally through the CNS rather than peripherally on the vascular system. Unlike PDE5 inhibitors (sildenafil, tadalafil) which act on genital blood flow, PT-141 modulates dopaminergic and other neurochemical pathways associated with sexual desire and arousal upstream of peripheral response. This mechanistic differentiation has been a primary driver of research interest, particularly for indications where vascular mechanisms are insufficient or contraindicated.

Origin: Derived from Melanotan II. A cyclic heptapeptide - the lactam ring structure (C2-C7) confers metabolic stability relative to linear peptide analogues. FDA approved in 2019 (Vyleesi, 1.75 mg) for HSDD in premenopausal women - the highest regulatory milestone of any compound in the research peptide category.

Research Context: One of only a handful of research peptides to complete the full Phase 1 through Phase 3 clinical development pathway and receive FDA approval. Robust human pharmacokinetic, safety, and efficacy data available from randomised controlled trials. Research-grade compound used to study MC3R/MC4R biology beyond the approved indication.

Sequence: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH  |  Lactam bridge: Asp(2)-Lys(7)  |  CAS: 189691-06-3

Molecular Formula: C₅₀H₆₈N₁₄O₁₀

Molecular Weight: 1,025.2 g/mol

CAS Number: 189691-06-3

Form: Lyophilised Solid