Botanical name: Lentinus edodes
© Steven Foster
Parts used and where grown
Wild shiitake mushrooms are native to Japan, China, and other Asian countries and typically
grow on fallen broadleaf trees. Shiitake is now widely cultivated throughout the world,
including the United States. The fruiting body is used medicinally.
Shiitake has been used in
connection with the following conditions (refer to the individual
health concern for complete information):
Historical or traditional use (may
or may not be supported by scientific studies)
Shiitake has been revered in Japan and China as both a food and medicinal herb for
thousands of years. Wu Ri, a physician from the Chinese Ming Dynasty era (A.D.
1368–1644), wrote extensively about this mushroom, noting its ability to increase
energy, cure colds, and eliminate
Shiitake contains proteins, fats, carbohydrates, soluble fiber, vitamins, and minerals. In addition,
shiitake’s key ingredient—found in the fruiting body—is a polysaccharide
called lentinan. Commercial preparations employ the powdered mycelium of the mushroom before
the cap and stem grow. This preparation is called lentinus edodes mycelium extract (LEM). LEM
is rich in polysaccharides and lignans.
One preliminary trial suggested that oral shiitake may be useful for people with hepatitis B.2 A highly purified,
intravenous form of lentinan is used in Japan and has been reported to increase survival in
people with recurrent stomach cancer,
particularly when used in combination with
chemotherapy.3 Similar findings have been found in one small clinical trial
with people suffering from pancreatic cancer.4 Case reports from Japan suggest that
intravenous lentinan may be helpful in treating people with HIV infection.5 However, large-scale
clinical trials to confirm this action have not yet been performed.
Oral supplementation of lentinan from shiitake has been shown to significantly reduce the
recurrence rate of genital warts (condyloma acuminata). A preliminary trial involving a group
of men and women with genital warts found that those who took 12.5 mg of lentinan twice a day
for two months after laser surgery had significantly fewer recurrences (10.53% recurrence
rate) compared to those who only had the laser surgery (47.06% recurrence
How much is usually taken?
The traditional intake of the whole, dried shiitake mushroom is 6–16 grams per
day.7 The mushroom is typically eaten in soups or taken as a decoction (i.e.,
boiled for 10–20 minutes, cooled, strained, and drunk). Recommended intake of LEM is
1–3 grams two to three times per day. Purified lentinan is considered a drug in Japan
and is not currently available as an herbal supplement in North America.
Are there any side effects or interactions?
Shiitake has an excellent record of safety but has been known to induce temporary diarrhea and abdominal bloating when used in high
amounts (above 15–20 grams per day). Its safety during pregnancy and breast feeding has not yet been
Are there any drug
Certain medicines may interact with shiitake. Refer to drug interactions for a list of those medicines.
1. Jones K. Shiitake: The Healing Mushroom. Rochester, VT:
Healing Arts Press, 1995.
2. Jones K. Shiitake: A major medicinal mushroom. Alt Compl Ther
3. Taguchi I. Clinical efficacy of lentinan on patients with stomach
cancer: End point results of a four-year follow-up survey. Cancer Detect Prevent
4. Matsuoka H, Seo Y, Wakasugi H, et al. Lentinan potentiates immunity
and prolongs survival time of some patients. Anticancer Res 1997;17:2751–6.
5. Hobbs C. Medicinal Mushrooms. Santa Cruz, CA: Botanica Press,
6. Guangwen Y, Jianbin Y, Dongqin L, et al. Immunomodulatory and
therapeutic effects of lentinan in treating condyloma acuminata. CJIM
7. Hobbs C. Medicinal Mushrooms. Santa Cruz, CA: Botanica Press,