Turkey tail mushroom (Trametes versicolor)
Summary
Most human evidence comes from PSK, a turkey tail extract prescribed in Japan, added to chemotherapy after gastric or colorectal cancer surgery; pooled trials found modestly better survival (grade C). Studies of over-the-counter turkey tail supplements are small and preliminary (grade D).
Key facts
- PSK plus chemotherapy: HR 0.88 for death across 8 RCTs (8,009 patients)[1]
- Network meta-analysis of 23 trials (10,684 patients): better 1–5-year survival with PSK, no increase in side effects[2]
- Up to 9 g/day of turkey tail mycelium for 6 weeks was tolerated after breast cancer treatment[3]
- In Japan, PSK is a prescribed product, not a supplement[3]
- 5 graded human outcomes on this page
- October 13, 2026
How it works
ProposedPSK and PSP are protein-bound beta-glucan polysaccharides thought to stimulate immune cells; a phase 1 trial reported dose-related rises in CD8+ T cells and B cells, and PSP shifted gut bacteria like a prebiotic in healthy volunteers.[3][4]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Cancer care | Grade C | Improved | Meta-analysis of 23 trials · n = 10,684 · 2017 | 3 rows |
| Immune | Grade D | Improved | RCT · n = 61 · 2014 | 1 row |
| Gut | Grade D | Mixed | RCT · n = 24 · 2014 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Survival in gastrointestinal cancers | Improved | Grade C | Meta-analysis · n = 10,684 · 2017 Patients with colorectal, oesophageal or gastric cancer in 23 RCTs Form: PSK with or without chemotherapy · Dose: As given in each trial · Duration: Varied PSK increased 1–5-year overall survival and 1–7-year disease-free survival, with no increase in side effects; strongest with chemotherapy in colorectal and gastric cancer. | 29179503 (opens PubMed)Source [2] |
| Survival after curative gastric cancer surgery | Improved | Grade C | Meta-analysis · n = 8,009 · 2007 Patients after curative gastric cancer resection in 8 RCTs Form: PSK added to chemotherapy · Dose: As given in each trial (not stated in abstract) · Duration: Varied Overall hazard ratio for death 0.88 (95% CI 0.79–0.98) with PSK immunochemotherapy vs chemotherapy alone. | 17106715 (opens PubMed)Source [1] |
| Clearance of oral HPV 16/18 | Improved | Grade D | RCT · n = 61 · 2014 Adults with gingivitis positive for oral HPV16 or HPV18 Form: Trametes versicolor + Ganoderma lucidum vs Laetiporus sulphureus · Dose: Daily mushroom preparation (dose not stated in abstract) · Duration: 2 months HPV cleared in 88% with turkey tail plus reishi vs 5% with the comparison mushroom (P < 0.001). | 25271984 (opens PubMed)Source [5] |
| Gut microbiome composition | Mixed | Grade D | RCT · n = 24 · 2014 Healthy volunteers (22 completed) Form: PSP from Trametes versicolor vs amoxicillin vs no treatment · Dose: Daily PSP (dose not stated in abstract) · Duration: 8 weeks of sampling PSP produced clear, consistent microbiome changes consistent with a prebiotic effect; baseline microbiomes stayed stable. | 25006989 (opens PubMed)Source [4] |
| Tolerability and immune markers after breast cancer radiotherapy | Mixed | Grade D | Open-label trial · n = 9 · 2012 Women after breast cancer radiotherapy (9 of 11 completed; USA) Form: Freeze-dried Trametes versicolor mycelium · Dose: 3, 6 or 9 g/day · Duration: 6 weeks Nine adverse events (7 mild, 1 moderate, 1 severe); trends towards higher lymphocyte counts and NK activity at 6–9 g/day. | 22701186 (opens PubMed)Source [3] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| PSK (polysaccharide-K, Krestin) | Varies[1][3] | Standardised extract given orally in Japanese cancer trials.[1][3] | Pooled trials found no increase in side effects.[2] | Survival after GI cancer surgery |
| Mycelium or fruiting-body powder supplements | Varies[3] | Not standardised to PSK or PSP content.[3] | Up to 9 g/day tolerated for 6 weeks in a phase 1 trial.[3] | Immune markers (phase 1) |
| PSP (polysaccharide-peptide) | Varies[3][4] | A related hot-water extract.[3][4] | No adverse effects reported in the cited abstract.[4] | Gut microbiome |
Studied doses
Doses studied in human trials ranged from 3 g/day to 9 g/day of turkey tail mycelium powder for 6 weeks; the PSK cancer trials used a prescription extract at doses not reported in the pooled abstracts.[3]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- People in cancer treatment
- The survival data are for prescription PSK given with chemotherapy under oncology care. MSK notes rare low-grade blood and gut toxicities when used with chemotherapy (possibly from the chemotherapy itself); discuss any mushroom product with the oncology team.[1][3][6]
- Medicines
- No drug-interaction studies were found among the trials cited here, and MSK lists no known herb-drug interactions; tell your clinician, especially during chemotherapy.[1][2][3][6]
- Pregnancy and breastfeeding
- MSK advises pregnant or breastfeeding women to avoid turkey tail until safety data are available.[6]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Frequently asked questions
Does turkey tail help in cancer?
PSK, a turkey tail extract prescribed in Japan, added to chemotherapy modestly improved survival after gastric and colorectal cancer surgery in pooled trials; this is adjunct care, not a replacement for cancer treatment.[1][2]
Is turkey tail safe?
Up to 9 g/day was tolerated for 6 weeks in a small phase 1 study, and PSK trials reported no increase in side effects.[2][3]
What is the difference between PSK and PSP?
Both are similar hot-water extracts of turkey tail containing protein-bound polysaccharides; PSK is the one used in the pooled cancer trials.[3]
Does turkey tail help gut health?
In 24 healthy volunteers, PSP shifted gut bacteria in a prebiotic-like way; health effects were not measured.[4]
Sources
- [1]Efficacy of adjuvant immunochemotherapy with polysaccharide K for patients with curative resections of gastric cancer.. Cancer Immunol Immunother, 2007. meta-analysis
- [2]Can polysaccharide K improve therapeutic efficacy and safety in gastrointestinal cancer? a systematic review and network meta-analysis.. Oncotarget, 2017. meta-analysis
- [3]Phase 1 Clinical Trial of Trametes versicolor in Women with Breast Cancer.. ISRN Oncol, 2012. open-label
- [4]Effects of polysaccharopeptide from Trametes versicolor and amoxicillin on the gut microbiome of healthy volunteers: a randomized clinical trial.. Gut Microbes, 2014. RCT
- [5]Control of oral human papillomavirus (HPV) by medicinal mushrooms, Trametes versicolor and Ganoderma lucidum: a preliminary clinical trial.. Int J Med Mushrooms, 2014. RCT
- [6]Coriolus Versicolor (About Herbs). Memorial Sloan Kettering Cancer Center, 2026. database
What changed
- Editorial evidence re-review: added Memorial Sloan Kettering's monograph for the chemotherapy-toxicity note and the pregnancy/breastfeeding caution; PSK numbers and Fungi Perfecti product supply re-checked.
- Second-pass self-review: every PMID re-checked against NCBI esummary (title, year, no retraction or expression-of-concern flag), every dose, n and duration re-read against the PubMed abstract or PMC full text, grades held conservative, and interactions limited to what a cited source supports.
- First draft. Source titles and years taken from NCBI E-utilities esummary; abstracts read for every evidence row.