MCR-420

MCR-420 is a selective small molecule agonist of the melanocortin-4 receptor (MC4R), a G protein-coupled receptor that plays a central role in the hypothalamic regulation of energy homeostasis, appetite, and body weight. Developed by MCR Therapeutics, the compound is designed to mimic the action of the endogenous ligand alpha-melanocyte-stimulating hormone (α-MSH) within the leptin-melanocortin signaling pathway. By activating MC4R, MCR-420 promotes satiety and increases energy expenditure, making it a therapeutic candidate for the treatment of obesity and related metabolic disorders. The molecule was engineered for high selectivity toward the MC4R over other melanocortin receptor subtypes, such as MC1R and MC3R, to minimize off-target effects like skin pigmentation changes or adverse cardiovascular events.