Chaga

Also known as inonotus obliquus, chaga mushroom.

Last reviewed October 9, 2026 · Jump to references

What is Chaga?

In plain words

Chaga is a fungus that forms dark, hard growths on birch trees and is used in teas and extracts. The body digests or processes some of its substances, but how much reaches the bloodstream is not well understood. Researchers study it for possible effects on inflammation, immune function, and blood sugar, mostly in cells and animals. Benefits in people remain unproven, and kidney injury has been reported with heavy or prolonged intake.

Technical definition

Chaga is a fungal botanical derived primarily from the sterile conk of Inonotus obliquus, a parasitic fungus that grows on birch trees; it contains polysaccharides, polyphenols, and triterpenoids rather than a single defined active compound. Laboratory studies suggest effects on oxidative stress and immune-signaling pathways, but no single molecular target or clinically established mechanism has been identified. Chaga is marketed as a dietary supplement in the United States and is not FDA-approved to treat or prevent disease.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.