—To determine the efficacy of short-term administration of a synthetic analogue of α-melanotropin, [Nle4D-Phe7] (NDP)—α-melanocyte-stimulating hormone (MSH), in darkening (tanning) human skin.
—Randomized, placebo-controlled, double-blind clinical trial.
—Clinical research unit of a university medical center.
—Twenty-eight healthy white men with a history of either poor tanning (skin type I or II) or good tanning (skin type III or IV) recruited from advertisements and paid to participate in the study.
—Each subject received 10 subcutaneous injections of either a purified NDP preparation or saline over 12 days. They were followed up for 7 weeks after therapy was completed. All subjects used a high-potency sunscreen during the the trial.
Main Outcome Measure.
—Skin darkening was quantified by serial chromaticity measurements prior to, during, and after therapy.
—A significant parabolic curve of skin darkening activity was noted in subjects with skin type I or II (P,.001) and with skin type III or IV (P<<.001) who were given NDP. No darkening occurred in the subjects who were given a placebo. Peak changes were seen 1 to 3 weeks after therapy was completed.
—Human skin darkens as a response to a synthetic melanotropin given by subcutaneous injection. Skin tanning appears possible without potentially harmful exposure to ultraviolet radiation.(JAMA. 1991;266:2730-2736)