Mycology is the branch of biology, the study of fungi. Science and technologies have significantly improved the methods for extracting useful substances from chaga. Chaga takes a special place in mycology. The mushroom is one of the most useful medical mushrooms. It is the first nutraceutical - a useful tea product that supports health, and has therapeutic capacity to prevent from diseases. The American mycologist Paul E. Stamets distinguishes Chaga among other medical mushrooms.