Reishi Mushroom
Reishi Mushroom
This information describes the common uses of Reishi Mushroom, how it works, and its possible side effects.

Common Name

Ling zhi, Lin zi, Mushroom of immortality

How It Works

Reishi mushroom has antioxidant properties and may enhance immune response.

Reishi mushroom contains complex sugars known as beta-glucans. Lab studies suggest that these compounds may help stop the growth and spread of cancer cells. When animals were fed beta-glucans, some cells of their immune system became more active.

Limited data from clinical studies suggest reishi can strengthen immune response in humans. In addition, reishi mushrooms contain sterols that can act as precursors to hormones in the body, along with substances called triterpenes that may have blood pressure-lowering and anti-allergy effects. Reishi mushrooms have also been shown to slow blood clotting.

Reishi mushroom can cause toxicity in some immune cells. There are also a few documented cases of liver toxicity. More studies are needed to show that reishi is safe and effective for use with cancer treatment.

Purported Uses

  • To treat fatigue
    No scientific evidence supports this use.
  • To lower high cholesterol
    In one small study, a reishi mushroom product increased HDL-cholesterol level in patients with borderline elevations of cholesterol.
  • To treat HIV and AIDS
    Laboratory studies suggest that reishi mushroom may stimulate certain cells of the immune system, but evidence is lacking on reishi’s ability fight infections.
  • To lower high blood pressure
    Laboratory studies suggest that reishi mushroom may lower blood pressure. Human studies are lacking.
  • To stimulate the immune system
    Laboratory studies suggest that reishi mushroom may stimulate some cells of the immune system. A small clinical trial showed that reishi can enhance immune response in advanced-stage cancer patients. More studies are needed.
  • To reduce inflammation
    Laboratory studies suggest that reishi mushroom may have antihistamine effects. This has not been tested in humans.
  • For increased strength and stamina
    No scientific evidence supports this use.
  • To treat lower urinary tract symptoms (LUTS)
    One study suggests that reishi extracts may improve urinary flow in men with slight-to-moderate LUTS. Larger, long-term studies are needed to see if it can improve LUTS in men who have more severe symptoms.

Do Not Take If

  • You are taking warfarin or other blood thinners: Reishi may increase the risk of bleeding.
  • You are undergoing chemotherapy: In theory, reishi may make some chemotherapy drugs less effective.
  • You are taking immunosuppressants: Reishi can stimulate immune responses.
  • You are taking cytochrome P450 2E1, 1A2, and 3A substrate drugs: Lab studies suggest compounds in reishi may affect drug concentrations, although clinical relevance in not clear.

Side Effects

Nausea and insomnia have been reported in a few patients.

Case Reports

  • Liver toxicity: In two cases with the use of powdered reishi mushroom, one of which resulted in death.
  • Chronic diarrhea: In a 49-year-old man with non-Hodgkin’s lymphoma following long-term use of a powdered reishi mushroom extract.
  • Treatment error: A long-term user of reishi mushrooms was mistakenly treated for a parasite that in lab specimens appears similar in structure to reishi mushroom.