A review.This article will give a brief overview of the pharmacol. of the melanocortin receptors (MCRs) as a background.The review will not handle the patents or patent applications dealing with cloning of the different subtypes of the receptor, since this has been recently reviewed [1].This review will focus on different ligands acting either as agonists or antagonists to the different subtypes of the receptor, i.e., MC1R, MC3R, MC4R and MC5R.Just recently a number of patent applications have reached the public domain, which describe small peptides or low mol. weight organic compounds binding and acting on the MCRs.