Chaga (Inonotus obliquus)

Tier 3 — weak evidence · Antioxidant · Immunity · Anti-tumor

A birch tree fungus with extremely high antioxidant activity in lab tests, but no human trials support any health claim. All anticancer evidence is from cell and animal studies, not human research. High oxalate content may increase kidney stone risk, especially in people with chronic kidney disease. Hot water extraction is needed to release active compounds.

Dose: 1–3 g/day hot water extract; kidney stone risk from oxalates — avoid with CKD