These capsules are composed of ergothioneine, shiitake mushroom extract, and oyster mushroom extract to boost immunity, reduce inflammation, and ward off illness and disease. 

From the brand:

• L-ergothioneine is an amino acid and antioxidant primarily found throughout the body that we can only obtain through food, with mushrooms and fungi being the highest source.
  
• Shiitake and Oyster mushroom, apart from containing beneficial beta-glucans, contain some of the highest amounts of ergothioneine.
  
• Studies suggest that as we age, L-ergothioneine levels in the body decrease and supplementing with ergothioneine could help mitigate age related ailments.