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No active regulatory warnings
Sources: FDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
Updated: 2026-05-29 · v2.0 · Prof. G. Pkhakadze, MD, MPH, PhD📎 Cite 📄 PDF
1 Identity

Turkey Tail

Trametes versicolor (PSK/PSP)
Generally SafeEvidence: ModerateMushrooms
Turkey Tail (Trametes versicolor) is a common polypore mushroom named for its colorful, fan-shaped bands. It produces two clinically significant polysaccharide preparations: PSK (polysaccharide-K/Krestin) and PSP (polysaccharopeptide), which are among the most studied mushroom-derived immunomodulators globally [1]. PSK has been an approved adjuvant cancer therapy in Japan since 1977, with over 400 clinical studies and billions of dollars in sales [2]. It is used alongside chemotherapy for gastric, colorectal, and lung cancers, improving survival rates in multiple meta-analyses [3].
1
Turkey Tail
Trametes versicolor (PSK/PSP)
Generally SafeEvidence: ModerateMushrooms
Clinical verdict: Turkey Tail (PSK/Krestin) is the most clinically validated mushroom medicine — approved cancer adjuvant in Japan since 1977, with meta-analysis survival benefit in gastric and colorectal cancer. BUT: PSK is pharmaceutical-grade, not equivalent to OTC extracts. Always used WITH chemotherapy, never instead of. Beta-glucan immunostimulation is the mechanism [2] [3].
RDA
Typical 1–3 g
Target range
N/A
Upper limit
No UL
Evidence
Moderate
Population dosing — click to filter
🔗 Best with: Reishi, Cordyceps, Astragalus✅ USP Verified, ConsumerLab Approved, USDA Organic
2 Risk self-assessment
Not applicable — not an essential nutrient [1]
Select factors above to see your risk level
Clinical pearl for practitioners
SupplementIndex
Turkey Tail
Trametes versicolor (PSK/PSP) · Generally Safe · Evidence: Moderate
RDA
Typical 1–3 g
Upper limit
No UL
Evidence
Moderate
Clinical bottom line
Turkey Tail (PSK/Krestin) is the most clinically validated mushroom medicine — approved cancer adjuvant in Japan since 1977, with meta-analysis survival benefit in gastric and colorectal cancer. BUT: PSK is pharmaceutical-grade, not equivalent to OTC extracts. Always used WITH chemotherapy, never instead of. Beta-glucan immunostimulation is the mechanism [2] [3].
Do not miss
⚠ OTC Turkey Tail ≠ pharmaceutical PSK — different products [2]
⚠ Cancer adjuvant only — NEVER replace standard chemotherapy [3]
⚠ Transplant patients — immunostimulation risk [2]
⚠ PSK cancer evidence is robust: 8,000+ gastric cancer patients in meta-analysis [3]
Pregnancy
No safety data. Avoid [1].
4 Dietary sources
mg
Turkey Tail is too woody/tough to eat. It is consumed as tea or extract [1].
5 Lab interpreter

No routine monitoring

<12 Deficient
12–20 Insufficient
20–50 Optimal
50–100 Excess
>150 Toxic
Your level:
Enter a value above
⚕ For healthcare professionals. Does not replace clinical judgment.
6 Quick facts
CategoryMushrooms
Safety levelGenerally Safe
EvidenceModerate
RDATypical 1–3 g
Upper limit (UL)No UL
Scientific nameTrametes versicolor (PSK/PSP)
SpeciesTrametes versicolor (Polyporaceae) [1]
Active compoundsPSK (Krestin) and PSP (polysaccharopeptides) [2]
PSK in JapanApproved cancer adjuvant since 1977 — most studied mushroom medicine [2]
MechanismBeta-glucan immunostimulation: NK cells, T cells, dendritic cells [2]
Typical dose1,000–3,000 mg/day extract; PSK: 3 g/day in cancer trials [3]
Cancer adjuvant evidenceMeta-analyses positive for gastric, colorectal, lung cancer survival [3]
7 Dosage by population

Adults Moderate

See product label

Elderly Moderate

See product label
Consider reduced renal/hepatic clearance. Start at lower end of range.

Pregnancy Moderate

See guidance
No safety data. Avoid [1].

Pediatric Moderate

See guidance
No data. Not recommended [1].

Athletes Limited

Standard dose

Obesity Limited

Standard dose
Fat-soluble compounds may require dose adjustment in obesity.

Renal Limited

Consult specialist
Dose adjustment may be needed in renal impairment.

Vegan Moderate

Standard dose
PSK (Krestin): 3 g/day (pharmaceutical, Japan). OTC Turkey Tail extract: 1,000–3,000 mg/day. The clinical cancer survival data are primarily from PSK, which is a pharmaceutical preparation — OTC extracts may not be equivalent [2].
8 Form comparison
FormBioavailabilityVeganCost/day
['PSK (Krestin)', 'preferred', 'Pharmaceutical-grade protein-bound polysaccharide. Prescription drug in Japan. 3 g/day in cancer trials. Not easily available outside Japan [2].']StandardCheck label
['PSP (polysaccharopeptide)', '', 'Chinese preparation. Similar to PSK. Used in Chinese clinical trials [2].']StandardCheck label
['Turkey Tail hot water extract', 'common', 'OTC mushroom extract. Contains beta-glucans. NOT equivalent to pharmaceutical PSK but may have similar mechanisms at higher doses [1].']StandardCheck label
['Dual extract', '', 'Hot water + alcohol extraction. Captures broader range of compounds [1].']StandardCheck label
9 Clinical evidence

Strong evidence

PSK as cancer adjuvant: approved in Japan since 1977. Meta-analysis of 8,009 gastric cancer patients: improved 5-year survival. Meta-analysis of colorectal cancer: improved overall and disease-free survival. Used alongside standard chemotherapy, not as replacement [3]. Beta-glucan immunostimulation (NK cells, T cells, dendritic cells) well-established [2]. HIGH

Moderate evidence

PSP (Chinese trials): improved immune function and quality of life in cancer patients [2]. Breast cancer: Phase I trial at U. of Minnesota showed dose-dependent immune enhancement in post-treatment breast cancer patients [2]. HPV clearance: one small trial showed 88% HPV clearance with Turkey Tail vs 5% placebo [2]. MODERATE

Insufficient evidence

OTC Turkey Tail extract equivalence to PSK — not established [2]. Cancer prevention [1]. HIV/AIDS [1]. Chronic fatigue [1]. LOW
10 Safety

🚩 Red flags — when to stop and refer

● Patient using Turkey Tail INSTEAD OF chemotherapy — redirect to oncology [3]
● Transplant patient — immunostimulation [2]

Pregnancy

No safety data for supplements. Avoid [1].

Pediatric

No data. Not recommended [1].
11 Toxicity and overdose

12 Drug interactions
Immunosuppressants Major
Mechanism: Beta-glucan stimulation of innate immunity via Dectin-1. [2]
Effect: May oppose immunosuppression. [2]
Action: Avoid in transplant patients [2].
Chemotherapy Moderate (beneficial)
Mechanism: PSK enhances anti-tumor immune response alongside chemotherapy. [3]
Effect: Improved survival (adjuvant use). [3]
Action: Use WITH chemotherapy per oncologist guidance. Not standalone [3].
13 Supplement interactions

Best combined with

Reishi · 1,000–1,500 mg Reishi
Complementary mushroom polysaccharides and triterpenes [2].
14 Laboratory monitoring
No routine monitoring Primary
Target: N/A · N/A [2].
NK cell counts/activity in research settings [2].
15 Deficiency and prevalence
0%
[1]

Risk factors

• Not applicable — not an essential nutrient [1]
16 Frequently asked questions
Is Turkey Tail extract the same as PSK? ▼
No. PSK is a pharmaceutical-grade, standardized protein-bound polysaccharide approved in Japan. OTC Turkey Tail extracts contain beta-glucans and may have similar mechanisms, but they are NOT equivalent to PSK in standardization or clinical evidence [2].
Does Turkey Tail treat cancer? ▼
PSK (the pharmaceutical preparation) is an adjuvant — it improves survival WHEN USED WITH chemotherapy. It does NOT replace chemotherapy. Meta-analyses show clear survival benefit in gastric and colorectal cancers [3]. OTC extracts may have immune benefits but lack the same evidence.
Why is Turkey Tail the most evidence-based mushroom? ▼
Because PSK was developed as a pharmaceutical in Japan in the 1970s and has been studied in large-scale clinical trials (8,000+ gastric cancer patients). No other mushroom preparation has this level of clinical evidence [3].
Can I use Turkey Tail if I'm healthy? ▼
For general immune support, Turkey Tail beta-glucans may enhance NK cell and T cell function [2]. The evidence for healthy individuals is weak, but it has a good safety profile.
17 Regulatory status
Japan: PSK (Krestin): approved cancer adjuvant since 1977. Covered by insurance for gastric, colorectal, and lung cancer [2].
China: PSP: used in cancer support. Available as supplement and pharmaceutical [2].
United States (FDA): Dietary supplement. PSK not FDA-approved as drug. Clinical trials underway (NIH) [1].
South Korea: Available as dietary supplement and pharmaceutical.
18 References
[1]Standish LJ, et al. Trametes versicolor mushroom immune therapy in breast cancer. J Soc Integr Oncol. 2008;6(3):122-128. REVIEW
[2]Fritz H, et al. Polysaccharide K and Coriolus versicolor extracts for lung cancer: a systematic review. Integr Cancer Ther. 2015;14(3):201-211. doi:10.1177/1534735415572883 META-ANALYSIS
[3]Oba K, et al. Individual patient based meta-analysis of adjuvant immunochemotherapy with PSK for gastric cancer. Br J Cancer. 2007;97(7):859-862. doi:10.1038/sj.bjc.6603968 META-ANALYSIS
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20 Cite this page
Vancouver
Pkhakadze G. Turkey Tail — safety profile [Internet]. Tbilisi: Public Health Institute of Georgia; 2026 [cited 2026 May 30]. Available from: https://supplement.ge/ingredients/turkey-tail/
APA 7th
Pkhakadze, G. (2026). Turkey Tail — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/turkey-tail/
CC BY 4.0
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Reviewed by Prof. G. Pkhakadze, MD, MPH, PhD
Editor-in-Chief, Georgian Medical Journal · Chair, PHIG
Last reviewed: May 2026 · Next: November 2026
This entry is provided for educational and public health purposes under CC BY 4.0. Consult your healthcare provider before starting any supplement. For corrections: info@accreditation.ge.
Publisher: PHIG · Editor-in-Chief: Prof. Giorgi Pkhakadze, MD, MPH, PhD