PT-141

PT-141 (bremelanotide) is a synthetic cyclic heptapeptide melanocortin receptor agonist. It is a metabolite of Melanotan II and was found to act on central melanocortin pathways independently of melanogenesis.

PT-141 acts centrally, on melanocortin receptors in the hypothalamus and limbic system, which makes it a tool for studying melanocortin signalling in the brain.

PT-141 acts primarily through central melanocortin receptor activation:

MC3R/MC4R Activation PT-141 is an agonist at melanocortin-3 and melanocortin-4 receptors, which are expressed in brain regions involved in sexual behavior, including the hypothalamus and limbic system. MC4R activation in particular is the focus of most published work.

Central Nervous System Action PT-141 acts on central rather than peripheral pathways, which published animal studies use to separate motivational behaviour from peripheral vascular effects.

Dopamine System Interaction The melanocortin system interacts with dopaminergic pathways involved in reward and motivation. PT-141's effects may partially involve modulation of dopamine signaling in relevant brain circuits.

Limited Melanogenic Effect While PT-141 retains some ability to activate MC1R (the pigmentation receptor), its cyclic structure and modifications result in reduced melanogenic activity compared to its precursor Melanotan II.