Ergothioneine (EGT) is a natural amino acid with potent antioxidant activity. It is a water-soluble cosmetic raw material; it has good light and heat stability, and is not easily decomposed by oxidation. Therefore, ergothioneine is easy to be compatible with other active materials in cosmetics formulas. Moreover, ergothioneine is non-toxic in epidermal cells, so it will not produce any irritation when used topically with safety and effectiveness.