Chaga Mushroom

Common Names

  • Cinder conk
  • birch conk
  • clinker polypore

For Patients & Caregivers

How It Works

Human studies on the anticancer and immunostimulating effects of chaga mushroom are needed.
Chaga mushroom is found in Russia and has been used in folk medicine for various ailments across northern Europe. Laboratory and animal studies show that compounds in chaga can kill cancer cells selectively and stimulate the immune system. It may also have benefits such as reductions in fatigue and inflammation, as well as increased mental sharpness. However, clinical trials are needed to confirm chaga’s safety and effectiveness for these uses. In addition, chaga may interact with some drugs and is high in oxalates, which may prevent the absorption of some nutrients and can be toxic in high doses.

Purported Uses

  • To prevent and treat cancer
    Laboratory and animal studies show that chaga can inhibit cancer progression. Studies in humans are needed.
  • To stimulate the immune system
    Laboratory and animal studies show that chaga can activate some types of immune cells. Studies in humans are needed.
  • To reduce inflammation
    Laboratory and animal studies suggest anti-inflammatory effects. A small study in humans also suggested a reduction in markers related to inflammation. Additional clinical trials for this use are needed.
  • To protect the liver
    Although protective effects have been reported, these benefits have not yet been studied or confirmed.

Do Not Take If

  • You are taking blood-thinning medications (eg, warfarin): Laboratory studies suggest that chaga may cause additional effects.
  • You are taking diabetic medications: Laboratory studies suggest that chaga may also lower blood sugar, causing additional effects.

Side Effects

No clinical trials have assessed chaga’s safety, so there is a lack of information on possible side effects.

Case report

Kidney damage/disease: In a 72-year-old Japanese woman with liver cancer, caused by taking chaga daily for 6 months.

Special Point

Chaga is high in oxalates, which may prevent the absorption of some nutrients and can be toxic in high doses.

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For Healthcare Professionals

Scientific Name

Inonotus obliquus

Clinical Summary

Chaga mushroom is found on birch and other trees in cold climates. It has been used as a folk remedy for cancer, digestive system diseases, and various ailments in Russia and other northern European countries. The conk that is used medicinally comprises wood from the substrate tree and mycelium of the invasive fungus (12).

In vitro, chaga has demonstrated antitumor (12) (13), anti-mutagenic (9), antiviral (14), antiplatelet (2), antidiabetic (15), and analgesic (3) effects. In vivo studies also demonstrate immunomodulating (16), anti-inflammatory and pain-relieving properties (3).

In animal studies, chaga displayed anti-allergic (17), cognition-enhancing, and antioxidant activities (18). In murine colitis models, chaga exerted anti-inflammatory effects (19). Oral administration of polysaccharides from chaga increased exercise endurance and biological measures related to fatigue (20). Hypoglycemic effects in mice with diabetes mellitus were observed with administration of artificially-cultivated chaga (4).

Extracts and constituents of chaga have inhibitory and proapoptotic effects against colon cancer (5) (21) (22) and hepatoma (1) cells. Inotodiol from chaga exerted antitumor effects against cervical cancer cells (23). In some studies, chaga demonstrated selective apoptosis in tumor cells with no effects on healthy cells (1). It also reduced toxicity associated with radiation (6) and inhibited melanoma cell growth in animal models (7).

An extract of chaga reduced oxidative stress in lymphocytes from patients with inflammatory bowel disease (8). No clinical trials have been conducted to assess chaga’s safety and efficacy for disease prevention or for the treatment of cancer, cardiovascular disease, or diabetes.

In vitro studies suggest that constituents of chaga mushroom extract may interact with anticoagulant (2) and antidiabetic drugs (15). Chaga mushrooms are very high in oxalates and excessive intake may have toxic effects (24).

Because natural reserves of this fungus have nearly been exhausted, scientists are seeking to develop cultivated substitutes of wild chaga (4) (25).

Food Sources

Although chaga is an edible fungus, it is not commonly ingested due to its bitter nature. Tea can be made from the whole mushroom.

Purported Uses

  • Anti-inflammatory
  • Cancer treatment and prevention
  • Hepatoprotective
  • Immunostimulation

Mechanism of Action

Oxalic, gallic, protocatechuic and p-hydroxybenzoic acids have been identified in chaga extracts (12). In vitro, antidiabetic effects are attributed to terpenoids that inhibit alpha-glucosidase (15). Anti-inflammatory and pain-relieving properties may occur via inhibition of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) (3). Immunomodulating effects are attributed to Th1/Th2 cytokine secretion in immune cells and regulation of antigen-specific antibody production (16). Anti-quorum sensing activity in chaga conks suggests broader anti-infection attributes beyond immunomodulatory effects (12).

In animal studies, a methanolic extract of chaga produced beneficial effects on learning and memory via decreased malondialdehyde and nitrite levels, decreased acetylcholinesterase activity, and restored glutathione, superoxide dismutase, and acetylcholine levels (18). Antifatigue effects were attributed to polysaccharides from chaga, which increased endurance and glycogen content of liver and muscle in mice, while decreasing blood lactic acid and serum urea nitrogen levels (20). Anti-inflammatory effects in animal colitis models were related to suppression of tumor necrosis factor (TNF)-alpha, iNOS, and interleukin (IL)-1beta (19).

3beta-hydroxy-lanosta-8, 24-dien-21-al, and inotodiol constituents in chaga produce antimutagenic and antioxidative activities (9). Water-soluble lignin derivatives have also been identified as bioactive constituents with anticancer properties (26). A hot-water extract of chaga exhibited inhibitory and proapoptotic actions against colon cancer cells via upregulation of Bax and caspase-3 and downregulation of Bcl-2 (5). Inhibition of colorectal cancer was exerted by the constituent ergosterol via downregulation of the beta-catenin pathway (21). Inotodiol, a triterpenoid isolated from chaga, inhibited proliferation of cervical cancer cells and induced apoptosis in vitro via increased Bax expression, decreased Bcl-2, cyclin E downregulation, and p27 up-regulation (23). Aqueous extracts of chaga inhibited growth of human hepatoma cells via G0/G1 phase cell-cycle arrest and selective apoptotic induction (1). This selective activation may result from pH changes in the tumor microenvironment (11). Other apoptotic characteristics can induce caspase cleavage and nuclear fragmentation (7). Like many medicinal mushrooms, beta glucans in chaga exert immunomodulating activities, binding to complement receptor 3 so that immune cells recognize cancer cells as “non-self” (10).

Adverse Reactions

As there have been no clinical trials to assess chaga’s safety, there is a lack of information with respect to potential side effects.

Case report
Oxalate nephropathy: In a 72-year-old Japanese woman with liver cancer, caused by the ingestion of chaga mushroom powder 4-5 tsps daily for 6 months (24).

Herb-Drug Interactions

  • Antiplatelet or anticoagulant drugs: Chaga extract can inhibit platelet aggregation (2). It may also have additive effects when used with anticoagulant/antiplatelet drugs.
  • Hypoglycemic agents: In vitro studies suggest that chaga may have additive effects in lowering blood sugar levels (15).

Dosage (OneMSK Only)


  1. Youn MJ, Kim JK, Park SY, et al. Chaga mushroom (Inonotus obliquus) induces G0/G1 arrest and apoptosis in human hepatoma HepG2 cells. World J Gastroenterol. Jan 28 2008;14(4):511-517.

  2. Park YM, Won JH, Kim YH, et al. In vivo and in vitro anti-inflammatory and anti-nociceptive effects of the methanol extract of Inonotus obliquus. J Ethnopharmacol. Oct 3 2005;101(1-3):120-128.

  3. Zhong XH, Ren K, Lu SJ, Yang SY, Sun DZ. Progress of research on Inonotus obliquus. Chin J Integr Med. Apr 2009;15(2):156-160.

  4. Najafzadeh M, Reynolds PD, Baumgartner A, Jerwood D, Anderson D. Chaga mushroom extract inhibits oxidative DNA damage in lymphocytes of patients with inflammatory bowel disease. Biofactors. 2007;31(3-4):191-200.

  5. Ham SS, Kim SH, Moon SY, et al. Antimutagenic effects of subfractions of Chaga mushroom (Inonotus obliquus) extract. Mutat Res. Jan 10 2009;672(1):55-59.

  6. Caifa Chen WZ, Gao X, Xiang X, et al. Aqueous Extract of Inonotus obliquus (Fr.) Pilat (Hymenochaetaceae) Significantly Inhibits the Growth of Sarcoma 180 by Inducing Apoptosis. Am J Pharmacol Toxicol. 2007. 2(1):10-17.

  7. Shashkina MY, Shashkin PN, Sergeev AV. Chemical and Medicobiological Properties of Chaga (Review). Pharmaceutical Chemistry Journal 2006. 40(10):560-568.

  8. Glamoclija J, Ciric A, Nikolic M, et al. Chemical characterization and biological activity of Chaga (Inonotus obliquus), a medicinal “mushroom”. J Ethnopharmacol. Mar 13 2015;162:323-332.

  9. Ying YM, Zhang LY, Zhang X, et al. Terpenoids with alpha-glucosidase inhibitory activity from the submerged culture of Inonotus obliquus. Phytochemistry. Dec 2014;108:171-176.

  10. Yoon TJ, Lee SJ, Kim EY, et al. Inhibitory effect of chaga mushroom extract on compound 48/80-induced anaphylactic shock and IgE production in mice. Int Immunopharmacol. Apr 2013;15(4):666-670.

  11. Yue Z, Xiuhong Z, Shuyan Y, et al. Effect of Inonotus Obliquus Polysaccharides on physical fatigue in mice. J Tradit Chin Med. Aug 2015;35(4):468-472.

  12. Kikuchi Y, Seta K, Ogawa Y, et al. Chaga mushroom-induced oxalate nephropathy. Clin Nephrol. Jun 2014;81(6):440-444.

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