GSH exerts its action as skin whitening agent at various levels of melanogenesis which include the following
-Interference with cellular transport of tyrosinase
-Direct inactivation of the enzyme tyrosinase by binding with the copper-containing active site of the enzyme
-Mediating the switch mechanism from eumelanin to phaeomelanin production as GSH is the major physiologic reservoir of cysteine and increase in cysteine levels results in switching of eumelanogenesis to pheomelanogenesis