[Nle4-D-Phe7]-alpha-melanocyte-stimulating hormone significantly increased pigmentation and decreased UV damage in fair-skinned Caucasian volunteers

This clinical study evaluated the photoprotective effects of afamelanotide (also known as Melanotan I or [Nle4-D-Phe7]-α-MSH) in 60 fair-skinned Caucasian volunteers (Fitzpatrick skin types I and II), the population at highest risk for UV damage and skin cancer. The peptide was administered by subcutaneous injection at doses of 0.16 mg/kg over several days.

The results were impressive across multiple protection parameters:

• Increase in melanin density by up to 41% in the fairest skin (type I)
• Reduction of more than 50% of sunburn cells after UV exposure
• Decrease of 59% in thymine dimer formation (direct DNA damage caused by UV)
• Visible tanning even in individuals who normally do not tan

These data are particularly significant because they demonstrate that afamelanotide not only darkens the skin cosmetically but provides real biological protection against UV radiation-induced DNA damage. The melanin produced is predominantly eumelanin (photoprotective), not pheomelanin (potentially pro-oxidant).

This study was pivotal for the clinical development of afamelanotide (marketed as Scenesse) as a treatment for extreme photosensitivity conditions, including erythropoietic protoporphyria. It demonstrated that pharmacologically induced melanogenesis can provide substantial UV protection even in individuals genetically predisposed to sunburn.