The present disclosure provides a method of inducing or promoting darkening of the skin and/or melanogenesis, a method of treating a skin condition or disorder, in particular hypopigmentation, comprising administration of a polycationic aliphatic amine, wherein said polycationic aliphatic amine preferably is putrescine, spermidine and spermine. The invention further includes corresponding methods of reducing or preventing darkening of skin and/or melanogenesis, or related methods of treating a skin condition or disorder, comprising administration of at least an inhibitor of polycationic aliphatic amine transport or synthesis, wherein said inhibitor is preferably trimer44NMe or difluoromethylornithine (DFMO) respectively.
