99% Organic Ergothioneine Mushroom Complex From the Manufacturer Benefits: Heart Health* Immune Support* Free Radical Protection* Healthy Oxidative Stress Levels* Telomere Length* Healthy Aging* Skin Health* L-ergothioneine: Strong Antioxidant: Ergothioneine is a potent antioxidant that promotes the defense against free radicals. Skin Health: High levels of ergothioneine have been detected in skin tissues, and it is thought to help prevent UV radiation damage and slow down the aging process. Immune System Support: Some studies suggest that ergothioneine may support the immune system.