What is it? Overview Usage Side Effects and Warnings

What is Reishi?

The tree fungus known as reishi has a long history of use in China and Japan as a semi-magical healing herb. More revered than ginseng and, up until recently, more rare, many stories tell of people with severe illnesses journeying immense distances to find it. Presently, reishi is artificially cultivated and widely available in stores that sell herb products.

Reishi (like its fungi “cousins” maitake , Coriolus versicolor , and shiitake ) is marketed as a kind of cure-all, said to strengthen immunity , help prevent cancer , and also possibly treat cancer as well. It is also said to be useful for autoimmune diseases (such as myasthenia gravis and multiple sclerosis ), viral infections, high blood pressure , diabetes , enhancing mental function , altitude sickness , ulcers , common colds and insomnia . However, while there has been a great deal of basic scientific research into the chemical constituents of reishi, reliable double-blind, placebo-controlled studies are all but nonexistent. (For information on why such studies are essential, see Why Does This Database Rely on Double-blind Studies?...

Safety Issues

Because it is used as food in Asia, reishi is generally regarded as safe. One small study evaluating the safety of reishi when taken at a dose of 2 g daily for 10 days failed to find any evidence of ill effects. 1 However, another study found indications that reishi impairs blood clotting. 2 For this reason, prudence suggests that individuals with bleeding problems should avoid reishi; the herb should also be avoided in the period just before and after surgery or labor and delivery. Furthermore, individuals taking medications that impair blood clotting, such as aspirin, warfarin (Coumadin), heparin, clopidogrel (Plavix ), pentoxifylline (Trental ), or ticlopidine (Ticlid), should only use reishi under a doctor’s supervision.

Safety in young children, pregnant...