PT-141 (Bremelanotide)

Overview

PT-141 (Bremelanotide) is a synthetic melanocortin peptide that activates MC3R and MC4R (melanocortin-3 and -4 receptors) in the central nervous system. Unlike PDE5 inhibitors that work on vascular smooth muscle, PT-141 acts on CNS pathways that govern sexual desire and arousal, representing a fundamentally different approach to sexual function research.

Mechanism of Action

PT-141 activates melanocortin-4 receptors in the hypothalamus and limbic system, which are involved in the neural circuits governing sexual motivation and arousal. This central mechanism of action means it affects desire (libido) rather than just erectile hydraulics. The melanocortin system is downstream of dopaminergic signaling, creating a pathway from desire to physiological arousal.

Research Context

PT-141 received FDA approval (as Vyleesi) for hypoactive sexual desire disorder in premenopausal women. Clinical trials demonstrated increased sexual desire and decreased distress related to low desire. Research in male subjects has also shown pro-erectile effects independent of vascular pathways.

Key Research Areas

Considerations for Researchers

Most commonly administered subcutaneously. Nausea is a reported side effect, likely related to melanocortin receptor activation in the area postrema. Store lyophilized at -20C. Reconstitute with BAC water.