Activation of the MC1 receptor is responsible for its effect on pigmentation, whereas its regulation of appetite, metabolism, and sexual behavior is mediated through both the MC3 and MC4 receptors.
A activación do receptor MC1 é o que produce o seu efecto sobre a pigmentación, entanto que o seu efecto sobre o apetito, metabolismo e sexualidade está mediado polos receptores MC3 e MC4.