Chaga, Clinker Polypore

Botanical Name: Inonotus obliquus

Common Names: Chaga, Birch Conk, Clinker Polypore, Cinder Conk, Gift from God (Siberia), Mushroom of Immortality (Siberia), Cancer Polypore (Norway), Wart Polypore (Finland), Diamond of the Forest (Japan), King of Plants (China)

Family: Hymenochaetaceae

Parts Used: Sterile Conk

Mycology & Identification: Inonotus obliquus is a parasitic fungus which grows beneath the bark or outer layers of wood on living, dead, standing or falling trees, erupting into conspicuous black conks, generally on birch but occasionally on other broadleaved species. It produces a conk of 25cm-40cm across, which is black, deeply cracked, very hard & brittle when dry, described as having a ‘tumour like’ or ‘burnt’  appearance. Unusually for a fungus the visible growth is not the fruiting body, but a sclerotia or mass of mycelium coloured black due to its high melanin content. The sterile conk breaks out through the bark after many years of infection inside the tree. The period between infection and tree death is usually around 20 years, but can be much longe

Chaga’s distribution is in the high latitude boreal forests of Northern Europe, Asia & North America. Only one birch in every 15,000 bears Chaga.

Growing & Harvesting:

Publicity and marketing around Chaga’s medicinal properties have led to it being systemically harvested for commercial production, and resulted in the wild population being greatly diminished in some areas. As a result Chaga is now widely cultivated, though many experts say that the cultivated conks do not contain comparable amounts of beneficial constituents to their wild counterparts.

As the part of the fungi used for medicine is not a fruiting body, but the actual myco-organism, wild harvesting without enough care and attention will remove the whole fungus which won’t be able to regrow. Siberian research showed that mushrooms between 15 and 30 years old are most prized, and so it is extremely important to harvest only a small amount of a single conk per tree, so that these mature fungi can regenerate.

If harvesting Chaga:

  • do so for personal consumption only
  • use a sharp, clean knife and take care not to damage the host tree
  • take no more than 1/3rd of a single conk
  • don’t harvest from the same tree within four years
  • only harvest from living birch trees. Dead birch = dead Chaga

Edibility & Nutrition: Not edible

Constituents: Unusually for a medicinal mushroom, some of Chaga’s most important constituents are derived from the bark of its host tree, the birch.

From the birch: betulinic acid derivatives, inotodiol, melano-glucan complexes

Also contains: polysacchardies, superoxide dismutase (SOD), phyto-sterols, B complex, copper, iron, calcium, zinc and manganese.

Qualities: Sweet, Cooling, Balancing, Grounding

Tastes: Earthy, Sweet, Neutral, Bitter

Medicinal Actions: Adaptogen, Anti-Bacterial, Anti-Inflammatory, Anti-Microbial, Anti-Neoplastic, Anti-Oxidant, Anti-Tumour, Anti-Viral, Immuno-Modulating, Regulates Blood Sugar


“pulls in extremes, sends energy down through a center” (Ullian)


  • Stimulates an underactive immune system and downregulates an overactive immune system. Of benefit in auto-immune conditions, and to generally build immunity & resilience to infections (Ullian)


  • Chaga is used as an adaptogen to build resilience to stress, relieve fatigue, promote longevity, and facilitate recovery from simple burnout as well as invasive cancer treatments like radiotherapy


  • Shown to have anti-viral properties against influenza strains, herpes simplex & HIV


  • Betulinic acid has wide ranging anti-cancer activity: leukaemia, malignant brain & peripheral nervous system cancers. Chaga’s strong immune-modulating activity contributes to its use in inoperable breast cancer, gastric, parotid (salivary), lung, skin, colorectal cancer, melanoma, and Hodgkin lymphoma (Powell, Gillam)
  • David Winston suggests Chaga is the strongest anti-cancer mushroom available
  • Chaga has a very high concentration of powerful anti-oxidant superoxide dismutase (SOD).Useful for those at risk from DNA mutation created by free radicals due to exposure to radiation, pesticides, pollutants etc (Ullian)

GIT Disorders

  • Melano-glucan complexes have a wide antimicrobial activity. Chaga has traditionally been used as an internal cleanser, for conditions like ulcers & gastritis (Powell)


  • has been shown to improve psoriasis


  • Betulin & betulinic acid are close in chemical structure to beneficial cholesterol, and can serve as precursors to it in the body, supporting cell membrane stabilisation and healthy hormone production (Ingram)

Blood Sugar Regulation

  • Beta glucans have a role in blood sugar regulation, and are useful for people who suffer abnormal blood sugar peaks (Ingram)

History & Folklore:

  • Alexander Sozhenitsyn’s The Cancer Ward mentions Chaga being drunk daily
  • Traditionally revered as a folk medicine in eastern Russia where it is boiled into a tea for cancers, infections and GIT disorders. Prevented the onset of degenerative diseases, used to boost physical stamina and attain long life.
  • Regarded as a cure for tumous among the Ojibwe of Northern Canada
  • The DNA of Siberian chaga is 30% closer to humans DNA than that of plants
  • The genus name ‘Inonotus’ translates as black fibre, and ‘obliquus’ refers to the pores being at an angle to the horizon. The name Chaga originated in Siberia as Czaga, which means mushroom in the Komi-Permyak language.


Preparations & Dosages:

Decoction, Double Extraction Method Tincture, Powder, Capsules

Historically prepared as a hot water extract. Simmer on a low heat for as long as possible e.g. up to five days. One way of doing this is to fill a thermos with water that is cooler than boiling temperature, and then add the ground chaga and leave it for two to three days.

Tea: 5g ground and boiled into tea

Extracts: 1-3gram per day

Cautions & Contraindications:

Chaga is generally safe & non toxic. It is not usual for people to have allergic reactions to it. Some authors caution against taking it alongisde penicillin, and intravenous glucose, and anticoagulants like aspirin, warfarin, dabigatran etc.


Gillam, Fred (2016) ‘Native Medicinal Mushrooms: An Overview of their Therapeutic Potential’ in The Herbalist, pp.3-6

Haines, Arthur

Ingram, Cass (2011) ‘The Healing Powers of Wild Chaga’ in Price-Pottenger Journal of Health & Healing, Volume 35, No.4, pp.6-11

Phillips, Roger (2006) Mushrooms, Macmillan Publishing, London

Powell, Martin (2013) ‘Medicinal Mushrooms: The Essential Guide’, Mycology Press

Ullian, Naomi(2016)

Vertolli, Michael


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