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Herb library · Mushroom · Lentinula edodes (Lentinus edodes)

Shiitake

A popular cooking mushroom from Japan and China, also sold in extracts for immunity. One small trial in healthy adults found changes in immune markers from eating it; the best-documented effect in people is an itchy, whip-like rash from eating it raw or undercooked.

Traditional use

An edible mushroom first grown in Japan and China and increasingly sold in Europe. NCI lists it among the more common of the more than 100 mushrooms used in Asia alongside cancer care.

What studies show

  • Limited

    Immune function: in a 2015 study, 52 healthy adults who ate 5 or 10 grams of dried shiitake daily for 4 weeks had more active immune cells, more salivary IgA and lower CRP (an inflammation marker) afterward. There was no placebo group, and immune markers are not the same as fewer infections.

  • Insufficient

    Cancer: shiitake is used alongside cancer care in Asia, but NCI's summary does not describe results for it in people.

Be careful of

Cautions

  • AllergyShiitake dermatitis: eating raw or undercooked shiitake can cause linear, itchy, raised red streaks across the trunk and limbs, starting hours to a week after eating and lasting up to 40 days. French poison centers recorded 59 cases in 2014 to 2019; all recovered.
  • AmountIn that series, eating more shiitake meant a longer-lasting rash. Cook shiitake thoroughly: the cause is thought to be lentinan, which heat breaks down.
  • Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.

Sources

  1. Medicinal Mushrooms (PDQ®)–Patient Version (opens in a new tab) · NIH · read September 25, 2026
  2. Consuming Lentinula edodes (Shiitake) Mushrooms Daily Improves Human Immunity (2015) (opens in a new tab) · NIH · read September 25, 2026
  3. Shiitake dermatitis: experience of the Poison Control Centre Network in France from 2014 to 2019 (2022) (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.