PT-141 (Bremelanotide) selectively activates Melanocortin Receptors (MC3R and MC4R) in the central nervous system (CNS).The peptide binds to MC3R and MC4R receptors in the hypothalamus, a region of the brain that regulates sexual arousal and motivation. This activation stimulates neurological pathways that control sexual desire and arousal, leading to an increase in sexual motivation.