Afamelanotide

How it works

For people whom light burns from within: a stronger alpha-MSH, the tanning hormone, switching on MC1R in pigment cells.

What it's made of

13 amino acids: alpha-MSH, the hormone that darkens the skin, with two changes (norleucine and a “mirror-image” phenylalanine) that make it more potent and longer-lasting. It was designed in Arizona in 1980.

What it's for

Prescribed for

Erythropoietic protoporphyria in adults: a rare disease in which light causes intense pain, like a burn from the inside.