What is PT-141 (Bremelanotide)? A Researcher's Guide to the Melanocortin Receptor Agonist

PT-141, also known as Bremelanotide, is a synthetic cyclic heptapeptide and non-selective melanocortin receptor agonist. It is a metabolite of Melanotan II (MT-2) and has been studied extensively for its centrally-mediated effects on sexual function, making it one of the most researched peptides in the field of sexual dysfunction pharmacology.

What is PT-141?

PT-141 is structurally derived from MT-2 through hydrolysis of the lactam bridge, resulting in a linear peptide with a distinct pharmacological profile. Unlike MT-2, PT-141 does not significantly stimulate melanogenesis, making it more selective for the sexual function-related melanocortin pathways.

Its primary receptor targets relevant to sexual function research are:

• MC3R (Melanocortin 3 Receptor) — involved in energy homeostasis and potentially in sexual behaviour modulation
• MC4R (Melanocortin 4 Receptor) — the primary receptor implicated in PT-141’s effects on sexual arousal and erectile function in preclinical models

Mechanism of Action

PT-141 acts centrally — unlike PDE5 inhibitors (e.g., sildenafil) which act peripherally on vascular smooth muscle, PT-141 activates melanocortin receptors in the central nervous system, particularly in the hypothalamus. This central mechanism of action is of significant research interest as it represents a distinct pathway for studying sexual function that is independent of vascular mechanisms.

MC4R activation in the paraventricular nucleus of the hypothalamus has been associated with pro-erectile signalling in animal models, and this pathway is the primary focus of PT-141 research.

Why PT-141 is of Research Interest

PT-141’s central mechanism distinguishes it from all other compounds studied for sexual dysfunction, making it a unique research tool. Key areas of ongoing research include:

• Male erectile dysfunction models (central vs. peripheral mechanisms)
• Female sexual arousal disorder research
• Hypothalamic melanocortin system and sexual behaviour
• MC4R pharmacology and CNS signalling
• Comparative studies with PDE5 inhibitors

PT-141 vs. MT-2

Understanding the distinction between PT-141 and its parent compound MT-2 is important for research design:

• MT-2 — cyclic; activates MC1R, MC3R, MC4R, MC5R; significant melanogenic activity alongside sexual function effects
• PT-141 — linear metabolite of MT-2; reduced MC1R activity; more selective for MC3R/MC4R-mediated sexual function pathways; minimal melanogenic effect

Sourcing PT-141 for Research

Research-grade PT-141 should be sourced from suppliers providing batch-specific Certificates of Analysis (CoA) confirming purity (>98%), identity, and potency. Lyophilised formats offer optimal stability for laboratory storage.

At Aura Peptides, our PT-141 is supplied as a research-grade lyophilised peptide with full CoA documentation, available as single vials or in 10x bulk packs for high-volume research programmes.

For research purposes only. Not intended for human or veterinary use.