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Botanical illustration of Chaga
MedicinalSourced entry

Chaga

Inonotus obliquus

A dark, crusty fungus that grows on birch trees, long used as a folk remedy in Siberia and Russia for immunity. It is very high in oxalate, and long-term use has caused kidney damage.

What is Chaga?

Plant family
Hymenochaetaceae, a family of bracket fungi that grow on trees
Parts used
The fungal growth (sclerotium) on the tree
Where it grows
Grows on birch trees in cold northern regions, mainly Siberia, North America and Scandinavia
Genus
Inonotus
Species
obliquus

Also called

Chaga Mushroom

Traditionally used for

  • Immune support
  • Digestive tea (traditional)

Traditionally described as

  • Immune support (traditional)

Health topics

Where Chaga appears in symptom search, and why. Being listed doesn't mean it's a proven treatment.

Traditions that use it

  • European Folk Medicine

    Long used as a folk remedy in Western Siberia and Russia for immunity and inflammation.

Safety

Toxicity testing

  • Chaga is very high in oxalate (about 143 mg per gram of powder), which can damage the kidneys. Patients have developed long-term kidney damage after taking chaga for months or years.[1]

  • In rats, high doses of chaga caused oxalate crystal deposits and kidney damage.[1]

What does the research say?

Traditional use

These are traditional uses, not proven treatments.

  • Chaga has a long history as a folk remedy in Western Siberia and Russia, where it is valued for supporting the immune system and easing inflammation.[2]

Laboratory & animal research

Lab and animal results show what might be worth studying in people. They don't show that the herb has these effects in humans.

  • In lab and animal studies, chaga compounds showed antioxidant, antimicrobial and anti-cancer effects and reduced inflammation, and water extracts and chaga melanin were active against several viruses, including flu viruses.[2]

  • Chaga polysaccharides (complex sugars) showed effects on immunity, gut bacteria, blood sugar, cholesterol, tumors and viruses in lab and animal studies. These haven't been confirmed in people.[3]

In short

Very high in oxalate; long-term use has caused kidney damage.

Sources

  1. [1] Kidney Injury Induced by High-Dose Chaga Mushroom Consumption: Experimental Evidence in a Rat Model — Journal of Korean Medical Science · DOI: 10.3346/jkms.2026.41.e37Peer-reviewed study
  2. [2] A brief overview of the medicinal and nutraceutical importance of Inonotus obliquus (chaga) mushrooms — Heliyon · DOI: 10.1016/j.heliyon.2024.e35638Peer-reviewed study
  3. [3] Inonotus obliquus Polysaccharides: Preparation, Structural Characteristics, Structure-Activity Relationships, Biological Activities and Applications — Nutrients · DOI: 10.3390/nu18071125Peer-reviewed study

This information is educational and traditional in nature, and is not a substitute for professional medical advice.