Cysteine (CYS) and Glutathione (GSH) are, respectively, an amino acid and an ubiquitous tripeptide (cysteine-glycine-glutamate) found in our bodies. Aside from their many ascribed biological functions as antioxidants, they have also a role in skin lightening. The main reported mechanisms of action for glutathione include direct inactivation of the enzyme tyrosinase, mediation of the mechanism of melanin production and quenching of free radicals and peroxides that contribute to tyrosinase activation and melanin formation.

a mixture of sunscreens, it helps to protect the skin from damage caused by sun exposure, particularly due to the protection from photoaging caused by UVA rays.