Ergothioneine is an amino acid that is found mainly in mushrooms, but also in king crab, meat from animals that have grazed on grasses containing ergothioneine, and other foods.Ergothioneine is sometimes applied directly to the skin to prevent wrinkles, anti-aging, and reduce sun damage.
link:https://www.tongzebio.com/cosmetics-ingredients/l-ergothioneine-powder.html
L-Ergothioneine Powder

