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Herb library · Mushroom · Trametes versicolor (Coriolus versicolor)

Turkey tail

A thin, fan-shaped bracket fungus striped brown and tan like a turkey's tail. An extract of it, PSK, has been given alongside chemotherapy in Japan since the 1970s, and it has been studied in thousands of patients.

Traditional use

Grows on dead logs worldwide. Known as Yun Zhi in traditional Chinese medicine, where it has long been used for lung conditions, and as kawaratake (roof tile fungus) in Japan. PSK (polysaccharide-K, or krestin) is a hot-water extract approved in Japan as an add-on to cancer care; a similar extract made in China is called PSP.

What studies show

  • Limited

    Stomach and colorectal cancer, with chemotherapy after surgery: in randomized trials in Japan, including a 2007 review of 8 trials in 8,009 people with stomach cancer, those given PSK with chemotherapy lived longer than those given chemotherapy alone, and colorectal studies found less recurrence. These studies used the PSK extract, not store-bought turkey tail.

  • Limited

    Lung and breast cancer: lung cancer trials reported improvements in immune function, weight, well-being or survival; breast cancer studies measured immune cells rather than how patients did.

  • Insufficient

    HPV infection (as a vaginal gel): a 2026 FIGO/IGCS statement found the studies small, short and industry-funded, and does not endorse routine use of any topical HPV product.

Be careful of

Cautions

  • NoteFew side effects have been reported in the Japanese PSK studies, which have followed thousands of patients.
  • NoteMany Trametes species are hard to tell from turkey tail without special testing, and the FDA does not regularly review how mushroom supplements are made, so products may differ.
  • ConditionThe FDA has not approved turkey tail or PSK for cancer or any other condition. It is studied as an addition to standard cancer care, never a replacement for it.
  • 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. Medicinal Mushrooms (PDQ®)–Health Professional Version (opens in a new tab) · NIH · read September 25, 2026
  3. FIGO/IGCS Statement on the efficacy of topical treatments for high-risk human papillomavirus (2026) (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.