The present invention relates to a novel imidazole compound or a pharmaceutically acceptable salt thereof having a melanocortin receptor agonistic activity, and medical use thereof. The present invention relates to an imidazole compound represented by general formula [I] [wherein : Ring A represents an optionally substituted aryl group or the like; R 1 represents a hydrogen atom, an optionally substituted alkyl group, or the like; R 2 represents a hydrogen atom, a halogen atom, or the like; and R 3 represents an optionally substituted alkyl group] or a pharmaceutically acceptable salt thereof.