Your body already makes a hormone that tells your skin to tan. Melanotan 2 is a synthetic peptide engineered to mimic that hormone but in a version that's more potent and Manhattan Keratopigmentation Figure 3 from The efficacy of afamelanotide and narrowband UV B phototherapy for repigmentation of vitiligo. Semantic Scholar my eye colour change between 2008 and 2021 until my 20s, my eyes were completely brown : r mildlyinteresting Ocular Melanosis Safe Eye Color Change with Kerato and Dr. Movshovich