<unk>  is thought to cause skin to darken by binding to the melanocortin 1 receptor which in turn drives melanogenesis.<unk>  has a half-life of 30 minutes. After the implant is injected, most of the drug is released within the first two days, with 90% released by the fifth day. By the tenth day no drug is detectable in plasma. Its metabolites, distribution, metabolism and excretion were not understood as of 2017.
Afamelanotide
Efgartigimod alfa
Astemizole
Crofelemer
Promazine
Tecovirimat
Viaspan
Retinol