# Chaga mushroom

Source: https://onco.cc/technologies/chaga-mushroom/  
OnCo record `chaga-mushroom` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Chaga is a fungus from birch trees, drunk as a tea or taken as powder in the belief that it fights cancer. It has never been tested for safety or benefit in people with cancer, and large daily amounts of the powder have caused kidney failure from oxalate in case reports.

## Summary

Chaga (Inonotus obliquus) is a folk remedy in Russia and northern Europe, including for cancer. Memorial Sloan Kettering's About Herbs page lists a long range of laboratory and animal effects, including killing of colon, lung, liver and cervical cancer cells in culture, and states that its safety and efficacy have yet to be evaluated in clinical studies. MSK records case reports of oxalate nephropathy: a 72-year-old woman with liver cancer who took 4 to 5 teaspoons of chaga powder daily for 6 months needed dialysis and her kidney function did not recover, and a 69-year-old man taking 10 to 15 g a day with vitamin C recovered after dialysis and steroids; a third man developed end-stage kidney disease after long-term use. Chaga inhibited platelets in mice and may add to anticoagulants and diabetes medicines. The graded harm is the kidney injury from concentrated powder; tea in ordinary amounts has not been studied either way.

## Fields

- Kind: Technology
- Status: concept
- Last checked: 2026-11-04
- Tags: complementary; supportive-care; evidence:harm
- Principle: Chaga contains oxalic acid and triterpenes such as inotodiol; the anticancer effects are from cell culture, and the oxalate load from concentrated powder is what has damaged kidneys.
- Strengths: Laboratory activity has prompted interest
- Limitations: No human trial of any kind; Oxalate kidney failure in case reports with daily powder; Possible bleeding and blood-sugar interactions

## Sources

- MSK About Herbs: Chaga mushroom (page last updated 20 February 2023): https://www.mskcc.org/cancer-care/integrative-medicine/herbs/chaga-mushroom

## Connected records

- technologies: [Cordyceps](https://onco.cc/technologies/cordyceps-fungus/), [Dietary supplements during cancer treatment: interactions and harms](https://onco.cc/technologies/dietary-supplements-treatment-interactions/), [Evidence-based integrative oncology](https://onco.cc/technologies/integrative-oncology/), [Maitake mushroom extracts](https://onco.cc/technologies/maitake-mushroom/)
- fronts: [Diet, Exercise & Lifestyle](https://onco.cc/fronts/nutrition-lifestyle/), [Supportive Care & Survivorship](https://onco.cc/fronts/supportive-care/)
- terms: [Unproven diet claims (alkaline, juice, 'anti-cancer' diets)](https://onco.cc/terms/unproven-diet-claims/)
- bottlenecks: [Misinformation and unproven therapies](https://onco.cc/bottlenecks/b-misinformation/)

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