The researchers got the same high HDL levels results when they blocked the hypothalamus' melanocortin 4 receptor (MC4R) either by knocking it out or shutting it down with other chemicals.

This paper investigated the associations between central neuromedin U(NMU) receptor 2(NMU2R) and melanocortin(MC) receptor pathway(MCR3/4) in regulation of food intake and energy homeostasis.

Novel 1, 2, 4-thiadiazole derivatives as melanocortin receptor modulators.