PT-141 Peptide

PT-141 is the C-terminal acid form of Melanotan II, differing from it by a single change at the end of the peptide chain, and it carries less pigmentation activity as a result. It is not receptor-selective. The prescribing information for the approved bremelanotide drug product describes a non-selective melanocortin agonist with an order of potency of MC1R, MC4R, MC3R, MC5R, MC2R. Published research focuses on MC3R and MC4R, which are concentrated in the brain rather than in skin cells. One key characteristic researchers have studied is its ability to cross the blood-brain barrier, the tightly sealed layer that keeps most molecules out of the central nervous system.

Once inside the brain, PT-141 activates MC4R, which triggers cyclic AMP production and downstream signaling in hypothalamic neurons. The hypothalamus is a brain region that controls many autonomic functions. Animal behavioral studies have used PT-141 to investigate how MC4R activation affects motivated behaviors and autonomic nervous system responses, using tools like c-fos immunohistochemistry (which marks recently activated neurons) to map which brain areas respond.

Pharmacokinetic studies have characterized how PT-141 is absorbed, distributed, and cleared from the body in experimental animals. Because it produces less pigmentation activity than Melanotan II, it serves as a useful research tool for separating brain-based melanocortin signaling from the pigmentation effects seen with the parent compound. For Research Use Only. Not intended for human or veterinary use.