Birch chaga (trutovik obliqua) is a parasitic fungus that has the appearance of a dark growth on the trunk of a birch tree. In folk medicine, decoctions from it have been used to treat cancerous tumors. Chaga is considered one of the most powerful antioxidants on the planet, due to its composition:

superoxide dismutase - inhibits chronic inflammation and blocks the interaction of free radicals with cells, reducing the risk of malignant tumors and a number of chronic diseases.
minerals: copper, selenium, zinc, iron, magnesium, potassium, calcium, sodium, manganese.
vitamins B1, B2, B3, D2.
plant substances acting as antioxidants and adaptogens.