The present invention relates to a compound having a structure selected from: Ac-Nle-Glu-His-D-Phe-Arg-Trp-NH2 (SEQ ID NO: 1); orAc-Nle-Gln-His-D-Phe-Arg-Trp-NH2 (SEQ ID NO: 2) or a pharmaceutically acceptable salt thereof. The compound of the salt thereof are particularly useful for the repair or prevention of damage of cellular DNA of dermal (skin) cells following UV irradiation in a mammal.