Coriolus versicolor is a common tree fungus, often seen by hikers as a stiff, rounded, horizontal protuberance from tree trunks, with concentric lines of varying color. In traditional Chinese herbal medicine, this fungus is used to strengthen overall vitality and treat lung and liver problems as well as other conditions.

What is Coriolus versicolor Used for Today?

Currently, extracts of Coriolus versicolor called polysaccharide-K (PSK) and polysaccharopeptide (PSP) are under study as immune stimulants for use alongside chemotherapy in the treatment of cancer. These two related substances, made from slightly different strains of the fungus, are thought to act as “biological response modifiers,” meaning that they affect the body’s response to cancer.

According to most but not all reported trials, most of which were performed in Asia, both PSK and PSP can enhance the effects of various forms of standard cancer treatment.1-9

For example, in a 28-day double-blind, placebo-controlled study of 34 people with advanced non–small-cell lung cancer, use of Coriolus extracts along with conventional treatment significantly slowed the progression of the disease.2

It is thought that Coriolus extracts work by stimulating the body’s own cancer-fighting cells.3 PSK and PSP may also have cancer-preventive effects.

In addition, very weak evidence hints that extracts of Coriolus versicolor might be helpful for HIV infection.10

Dosage

A typical dosage of PSK or PSP as an adjunct to standard cancer treatment is 2 to 6 grams daily. For prevention of cancer, some experts recommend 500 mg daily, but there is no real scientific basis for this recommendation.

Safety Issues

According to Chinese studies, PSP and PSK appear to be relatively nontoxic, both in the short and long term.9,11,12

Few side effects have been reported in clinical trials. However, safety in young children, pregnant or nursing women, or people with severe liver or kidney disease has not been established.