Great Lakes Treats authentic wild harvested sliced Reishi (Gandoderma tsugae). Foraged and hand harvested. Great Lakes Treats takes pride in being certified by the Institute of Sustainable Foragers and dedicated to the practice of giving back to nature. Reishi mushroom is used for aging, boosting the immune system; viral infections such as the flu (influenza), swine flu, and avian flu; lung conditions including asthma and bronchitis; heart disease and contributing conditions such as high blood pressure and high cholesterol; diabetes; kidney disease; cancer; polyps (growths) in the colon or rectum, and liver disease. It is also used for HIV/AIDS, altitude sickness, symptoms in the urinary tract in men, chronic fatigue syndrome (CFS), trouble sleeping (insomnia), stomach ulcers, poisoning, and herpes pain.