PT-141 (Bremelanotide) (10mg)

PT-141 (bremelanotide) is a synthetic cyclic heptapeptide derived from Melanotan II, developed through targeted optimisation to focus on central sexual function pathways while minimising peripheral pigmentation effects. It acts as a non-selective melanocortin receptor agonist with primary activity at MC3R and MC4R — receptors highly expressed in hypothalamic and limbic regions governing sexual motivation, arousal, and reward.

Unlike PDE5 inhibitors (e.g., sildenafil), which work peripherally via vascular smooth muscle relaxation, PT-141 acts centrally to increase dopamine release in reward pathways and modulate serotonin in sexual motivation circuits. This central mechanism of action allows PT-141 to address desire and arousal at the neurological level rather than just facilitating blood flow, making it relevant for research into hypoactive sexual desire disorder (HSDD), sexual motivation, and central sexual dysfunction models.

PT-141 received FDA approval in 2019 as Vyleesi® (1.75 mg SC injection) for HSDD in premenopausal women — one of the few peptide compounds to receive regulatory approval for sexual health. Clinical trials demonstrated significant improvements in sexual desire scores and reductions in personal distress. In male research models, central MC4R activation has been associated with improved erectile responses.