Trametes versicolor (synonym Coriolus versicolor) · supplement
Evidence tier: insufficient
Turkey tail is Trametes versicolor, a thin bracket fungus whose banded, fan shaped caps look like a wild turkey's tail. It grows on dead hardwood and is sold as a tea, an extract or in capsules.
The protein bound polysaccharides PSK and PSP increase immune cell activity (MSK). Outside cancer care the effect on health is untested.
No usable consumer evidence. The real human evidence is for PSK, a prescription extract in Japan, given with chemotherapy after cancer surgery: a meta analysis of 8,009 gastric cancer patients (PMID 17106715) and a Cochrane review in colorectal cancer that was uncertain about any effect on chemotherapy side effects (very low certainty) and found low certainty evidence of a small effect on 5 year survival (PMID 36445793); MSK (updated 2026-04-22) says PSK appears to improve survival in gastric and colorectal cancer. None of that is in healthy people and none can be cited by a supplement brand. No trial shows a benefit for a healthy person.
No consumer dose is established; MSK prints none. PSK in the cancer trials was a prescription adjunct given under medical supervision, not a wellness dose.
Generally well tolerated. Reported effects are dark coloured stools and darkening of the fingernails [MSK]. A PSK or PSP standardised extract is a different product from raw powder.
Pregnancy: avoid
Breastfeeding: avoid
Active compounds: PSK (polysaccharide-K, Krestin), PSP (polysaccharide-peptide), beta-glucans
Remedies using Turkey Tail · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.