✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
📰Read the full Turkey Tail evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ 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]
ℹ️ Not obtained from food. Not applicable — this is not obtained from food in meaningful amounts; supplementation is the practical route.
🔬 Lab interpreter
Recommended test
No routine monitoring
No routine monitoring
Reference range / target
N/A
N/A
NK cell counts/activity in research settings [2].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
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].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
No safety data. Avoid [1].
👦 Pediatric: See guidance
No data. Not recommended [1].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: Can be taken any time [2].
💊 With food: With or without food [2].
🚫 Avoid: Immunosuppressants [2].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['PSK (Krestin)', 'preferred', 'Pharmaceutical-grade protein-bound polysaccharide. Prescription drug in Japan. 3 g/day in cancer trials. Not easily available outside Japan [2].'] | Standard | Check label | |
| ['PSP (polysaccharopeptide)', '', 'Chinese preparation. Similar to PSK. Used in Chinese clinical trials [2].'] | Standard | Check 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].'] | Standard | Check label | |
| ['Dual extract', '', 'Hot water + alcohol extraction. Captures broader range of compounds [1].'] | Standard | Check label |
3 Common 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.
4 Clinical evidence
Strong
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
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
5 Safety, toxicity & adverse events
Relative
⚠ Autoimmune disease — immunomodulatory activity
⚠ Mushroom hypersensitivity
⚠ Pregnancy and lactation — insufficient safety data
🚩 Red flags
● Patient using Turkey Tail INSTEAD OF chemotherapy — redirect to oncology [3]
● Transplant patient — immunostimulation [2]
6 Interactions
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].
Supplement synergies
Reishi · 1,000–1,500 mg Reishi
Complementary mushroom polysaccharides and triterpenes [2].
Complementary mushroom polysaccharides and triterpenes [2].
7 Regulatory
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.
8 US supplement products
1
on-market products containing Turkey Tail (NIH DSLD)
Brands carrying Turkey Tail (1)
Click a brand to see its Turkey Tail products.
9 Cite this page
Vancouver: Pkhakadze G. Turkey Tail — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Aug 15]. 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/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: February 2027
References: 3 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Turkey Tail — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/turkey-tail/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG