Reishi
Reishi (Ganoderma lucidum) is a woody, bitter mushroom taken as tea or extract, not eaten. It has a long history in Chinese medicine, but reviews of the human trials find no clear benefit, and a few people have had liver injury.
No set daily amount
2 Cochrane reviews neither found strong evidence of a benefit
Cancer · not a substitute for treatment; any add-on effect unconfirmed
Heart and blood sugar · no clear effect on blood sugar, blood pressure, or cholesterol
- In food None too hard and bitter to eat
- In supplements Teas and extracts also powders and spore oil
- Studied compounds Beta-glucans, triterpenes the triterpenes make it bitter
- Main risk Liver injury rare, in case reports
From Cochrane reviews of reishi trials and the NIH National Cancer Institute summary on medicinal mushrooms. No food figures: reishi is not a food.
Where Reishi Comes From
Food supplies none. Reishi is a shelf fungus with a cork-like flesh, so every way of taking it starts with drying and grinding or simmering it.
- Teadried slices simmered in water for a long time; the traditional form, and very bitter
- Supplementscapsules of ground mushroom, hot water or alcohol extracts, and products made from the spores; the main source for most people
- Mushroom coffee and drink blendsusually hold an unstated amount mixed with other mushrooms
What Is Reishi?
Reishi is the Japanese name and lingzhi the Chinese one for Ganoderma lucidum, a polypore that grows from the base of hardwood trees. Its kidney-shaped cap is red-brown and looks varnished. It has been used in Chinese medicine for many centuries, long prized as a tonic.
Reishi Compounds: Beta-Glucans and Triterpenes
Research on reishi follows two groups of compounds. Polysaccharides, mostly beta-glucans, changed the activity of immune cells in lab and animal studies. Triterpenes, such as ganoderic acids, are what make the mushroom bitter, and they showed effects on cells in lab dishes.
What Reishi Trials in People Found
A Cochrane review of reishi in people with cancer found a handful of small trials, mostly from China and of low quality. It concluded there was not enough evidence to use reishi as a first treatment. Some trials found better immune measures or response when reishi was added to chemotherapy or radiation, which the authors said needed better trials.
A second Cochrane review looked at blood sugar, blood pressure, and cholesterol, mostly in people with type 2 diabetes or high blood pressure. Compared with placebo, reishi made no clear difference to any of them, and the review did not support its use for those risk factors.
Is Reishi Safe?
- Liver injurycase reports describe serious liver damage after reishi powder, including one death; some of these people had taken reishi in another form without problems
- Common side effectsdry mouth, itching, and stomach upset were reported in trials
- Medicinesinteractions are not well studied; ask a doctor before taking it with cancer treatment or long-term medicines
Reishi is often sold next to turkey tail, whose PSK extract has stronger trial data, and chaga, which has almost none in people.
Sources are listed at the end of this page. Not medical advice.
Reishi Extracts and Supplement Forms
A cup of reishi tea and a reishi tincture can hold mostly different compounds, because each one dissolves in a different liquid.
| Product | Mainly holds | Note |
|---|---|---|
| Hot water extract | Polysaccharides (beta-glucans) | The traditional tea method, concentrated |
| Alcohol extract | Triterpenes | Triterpenes dissolve poorly in water, so tea holds less of them |
| Dual extract | Both | Water and alcohol extracts combined |
| Ground mushroom | Some of each, much fiber | Not extracted; the form in the liver injury reports was a powder |
Tracking Reishi in Caltide
- Not totaled yetCaltide does not add up reishi compounds yet. Reishi tea adds almost no calories; for mushrooms you eat, mushrooms in the food library have their full breakdown.
Related Nutrients
Reishi Sources and References
The figures and claims on this page are checked against these sources.
- Cochrane: Ganoderma lucidum (Reishi mushroom) for cancer treatment (2016)
- Cochrane: Ganoderma lucidum mushroom for the treatment of cardiovascular risk factors (2015)
- NIH National Cancer Institute: Medicinal Mushrooms (PDQ), Health Professional Version
- Wanmuang et al. (2007): Fatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder
Questions About Reishi
Reishi (Ganoderma lucidum, called lingzhi in China) is a hard, woody mushroom with a shiny red-brown cap that grows on hardwood trees. It is too tough and bitter to eat, so it is taken as tea, powder, or extract.
There is no good evidence that it treats cancer. A Cochrane review of small, low-quality trials found it should not replace standard treatment; some trials suggested better immune measures when it was added, which needs confirming.
Trials so far say no. A Cochrane review of reishi for heart and blood sugar risk factors found no clear effect on blood sugar, blood pressure, or cholesterol compared with placebo.
Because of its triterpenes, such as ganoderic acids. They are one of the two main groups of compounds studied in reishi; the other is polysaccharides, mainly beta-glucans.
Reishi tea and extracts were mostly well tolerated in short trials, with dry mouth, itching, and stomach upset reported. There are case reports of serious liver injury after taking reishi powder.
A product made with both hot water and alcohol. Hot water pulls out the polysaccharides, while the triterpenes dissolve poorly in water and need alcohol, so the method decides which compounds end up in the product.
Not yet. Caltide does not total reishi compounds. Reishi tea has almost no calories, so it does not change your daily totals.
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