Mushrooms or frogs are fungi and fleshy and fruiting organs. Fungi also describe a variety of mushrooms with or without a stem. One of the most important effects of reishi mushroom is its ability to strengthen the immune system. Antioxidants are molecules that help prevent cell damage. Due to this important function, there is great interest in foods and supplements that can increase antioxidant status in the body. Reishi mushroom is a common mushroom used in oriental medicine.