✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
📰Read the full Reishi evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ Cancer patient — use only as adjunct to conventional treatment, with oncologist knowledge [3]
⚠ Transplant patient — beta-glucan immunostimulation opposes immunosuppression [2]
⚠ Patient on anticoagulants — triterpenes inhibit platelet aggregation [2]
⚠ Bitter taste = quality indicator (triterpenes). Non-bitter reishi may lack key actives [2]
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
Monitor LFTs if prolonged use [2].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Reishi is the most studied medicinal mushroom — beta-glucans for immunomodulation, triterpenes for anti-inflammation. Cochrane review: improves cancer treatment response as ADJUNCT (not standalone). Dual extraction preferred (captures both compound classes). Bitter taste = high triterpene content (good). Avoid in transplant patients (immunostimulation) [1] [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. Some prefer evening for calming effects [2].
💊 With food: Can be taken with or without food [2].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Dual extract (hot water + alcohol)', 'preferred', 'Captures both water-soluble polysaccharides and alcohol-soluble triterpenes. Both compound classes are important [2].'] | Standard | Check label | |
| ['Hot water extract', 'common', 'Primarily beta-glucans. Misses triterpenes [2].'] | Standard | Check label | |
| ['Spore powder', '', 'Reishi spores contain concentrated triterpenes but require shell-breaking for bioavailability [2].'] | Standard | Check label | |
| ['Dried sliced mushroom (tea)', '', 'Traditional preparation. Bitter. Variable potency [1].'] | Standard | Check label |
3 Common questions
Does reishi treat cancer? ▼
NOT as standalone treatment. A Cochrane review found that reishi ALONGSIDE conventional treatment improved response rates and quality of life [3]. It should NEVER replace standard oncology care. The immune-enhancing effects may support anti-tumor immunity as an adjunct.
Why is reishi so bitter? ▼
The bitterness comes from triterpenes (ganoderic acids) — these are also the anti-inflammatory active compounds. A bitter reishi product indicates high triterpene content, which is desirable [2]. Non-bitter reishi extract may be low in triterpenes.
Fruiting body or mycelium? ▼
Fruiting body: higher triterpene content. Mycelium: often grown on grain (starch filler concern). For reishi, fruiting body dual extract is generally preferred [2].
Can healthy people benefit? ▼
Traditional use for general wellness and 'longevity' is widespread in East Asia. Modern evidence supports modest immune modulation and sleep quality improvement. The evidence base for healthy individuals is weak [2].
4 Clinical evidence
Strong
Beta-glucan immunomodulation: activates macrophages, NK cells, and dendritic cells via Dectin-1 and complement receptor 3 — well-established pharmacology [2]. Triterpene anti-inflammatory activity (NF-κB, COX-2 inhibition) confirmed in vitro [2]. HIGH
Moderate
Cancer adjunct: a Cochrane review (n=373, 5 RCTs) found that reishi alongside conventional treatment increased tumor response rates and improved quality of life in cancer patients [3]. NOT as standalone cancer treatment. Immune function: some trials show enhanced NK cell activity [2]. Sleep quality: traditional use supported by a small Australian RCT showing improved sleep quality in neurasthenia patients [2]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Absolute contraindications
✕ Known mushroom hypersensitivity
Relative
⚠ Bleeding disorders or anticoagulant/antiplatelet therapy — antiplatelet effect
⚠ Low blood pressure — may lower it further
⚠ Discontinue ~2 weeks before surgery
⚠ Rare hepatotoxicity reported with powdered preparations
⚠ Pregnancy and lactation — insufficient safety data
🚩 Red flags
● Patient using reishi as sole cancer treatment — redirect to evidence-based oncology [3]
● Transplant patient on reishi — immunostimulation risk [2]
● Prolonged use + liver symptoms — check LFTs [2]
6 Interactions
Drug interactions
Anticoagulants/antiplatelets Moderate
Mechanism: Triterpenes inhibit platelet aggregation. [2]
Effect: Additive bleeding risk. [2]
Action: Monitor for bleeding. Discontinue 2 weeks pre-surgery [2].
Immunosuppressants Major
Mechanism: Beta-glucans stimulate innate immune function via Dectin-1. [2]
Effect: May reduce immunosuppression efficacy. [2]
Action: Avoid in transplant patients [2].
Supplement synergies
Turkey Tail (Trametes versicolor) · 1,000–3,000 mg Turkey Tail
Complementary mushroom polysaccharides (PSK/PSP from Turkey Tail + beta-glucans from Reishi) for comprehensive immune support [2].
Complementary mushroom polysaccharides (PSK/PSP from Turkey Tail + beta-glucans from Reishi) for comprehensive immune support [2].
Vitamin C · 500–1,000 mg
May enhance beta-glucan immune effects [2].
May enhance beta-glucan immune effects [2].
7 Regulatory
China: Official Chinese Pharmacopoeia ingredient. 2,000+ year medicinal history [1].
Japan: Kampo medicine ingredient. Available as supplement [1].
United States (FDA): Dietary supplement. No health claims [1].
South Korea: Official Korean Pharmacopoeia ingredient. Popular supplement [1].
8 US supplement products
19
on-market products containing Reishi (NIH DSLD)
Brands carrying Reishi (13)
Click a brand to see its Reishi products.
9 Frequently paired with
10 Cite this page
Vancouver: Pkhakadze G. Reishi — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Oct 17]. Available from: https://supplement.ge/ingredients/reishi/
APA 7th: Pkhakadze, G. (2026). Reishi — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/reishi/
📋 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: April 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. "Reishi — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/reishi/ 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