Melanin-concentrating hormone (MCH) is a cyclic neuropeptide that appears to be involved in a number of neuronal functions but with a major role in food intake and energy expenditure controls. MCH gene overexpression leads to obesity and insulin resistance whereas MCH gene null mice are hypophagic and lean and are resistant to ageing-associated increases in body weight and insulin resistance. Two melanin-concentrating hormone (MCH) receptors have been found in human brain while a single MCH receptor has been identified in rat and mouse.

It can be predicted that a strategy aiming at blocking MCH action on MCH receptors could be a successful therapeutic approach in the treatment of obesity and/or mood disorders. However, it cannot be anticipated which MCH receptors and corresponding neuronal pathways would be the target of MCH antagonists in humans. Indeed, because of the lack of suitable animal models the biological functions of MCHR2 remained unknown up to date.