An MC4R antagonist selectively inhibits [Nle4D-Phe7]-a-MSH binding to recombinant human MC4R over MC1R and MC3R (IC50s 11.63 >10000 and 1115 nM respectively) inhibits a-MSH-induced cAMP production in COS-1 cells expressing human MC4R from 0.1-100 UM reduces stress-induced decreases in the time spent in the light area of the light/dark exploration test in mice reverses restraint stress-induced decreases in food intake in rats