PT-141 (Bremelanotide)

PT-141 (bremelanotide) is a cyclic heptapeptide analog of α-melanocyte stimulating hormone (α-MSH), derived from the melanotan family but engineered to act primarily at the melanocortin 4 receptor (MC4R) with reduced activity at MC1R.

MC4R is expressed in central nervous system regions involved in sexual response — most notably the medial preoptic area of the hypothalamus and paraventricular nucleus. Activation engages downstream dopaminergic and oxytocinergic pathways that regulate sexual arousal, distinguishing PT-141 from PDE5 inhibitors (which act on peripheral vascular tissue).

Bremelanotide holds FDA approval (Vyleesi) for hypoactive sexual desire disorder in premenopausal women, providing the most extensively characterized clinical-trial dataset for any melanocortin agonist.

Research Applications

• Central melanocortin receptor pharmacology research.
• Sexual-arousal pathway research distinct from peripheral vascular mechanisms.
• MC4R signaling and downstream dopaminergic / oxytocinergic studies.