L-alpha-Melanocortin is a strong inhibitor of inflammation. It is a promising new anti-inflammatory and hepatoprotective peptide. Consequently, its melanocortin receptors (MC1, MC3, MC4 and MC5) could be possible targets for the development of new antiinflammatory drugs for chronic inflammatory liver disease. For a long time it has been believed that only the L-enantiomers of amino acids are present in higher animals, but recent investigations show that D-amino acids also exhibit physiological effects in vivo, despite their very small quantities. The aim of this study was to compare hepatoprotective effects of L-alpha-melanocortin and D-alpha-melanocortin using the acetaminophen model of chemical liver damage in male CBA mice.