(D-Arg2, Sar 4)-Dermorphin (1-4) is a tetrapeptide derivative of the peptide Dermorphin found in amphibian skin. (D-Arg2, Sar 4)-Dermorphin (1-4) has significant analgesic effects by binding to the μ-opioid receptor ( MOR ) in the body. (D-Arg2, Sar 4)-Dermorphin (1-4) can be used in the development of analgesic drugs.