PT-141, also known as Bremelanotide, is a synthetic peptide developed to help improve sexual function. It acts as a melanocortin receptor agonist, primarily targeting receptors involved in sexual arousal and desire. PT-141 is used to treat sexual dysfunctions such as hypoactive sexual desire disorder (HSDD) in women and erectile dysfunction in men. Unlike some other treatments, it works systemically, often administered via injection, to stimulate sexual arousal and desire. Its effects can occur within hours and last for several hours.