✓ No active regulatory warningsFDA MedWatch, EMA EudraVigilance, WHO VigiBase, WADA Prohibited List · 2026-05-29
📰Read the full Chaga evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ ZERO human clinical trials — all benefits are from in vitro/animal studies [1]
⚠ Oxalate nephropathy risk from daily raw chaga tea consumption [1]
⚠ Patient with kidney stone history — avoid raw chaga tea [1]
⚠ ORAC score is meaningless for health outcomes (USDA abandoned it in 2012) [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 standard monitoring
No standard monitoring
Reference range / target
N/A
N/A
Monitor creatinine/GFR if regular raw chaga tea consumption [1].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Chaga has the highest ORAC score and impressive preclinical data (betulinic acid, beta-glucans, melanin) — but essentially ZERO human clinical trials. It is the most hyped mushroom relative to its evidence base. High oxalate content poses kidney stone risk with raw tea consumption. All human health claims are extrapolated from lab studies [1] [2].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
No data. Avoid [1].
👦 Pediatric: See guidance
No data [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: Any time [1].
💊 With food: With or without food [1].
🚫 Avoid: Raw chaga tea in large volumes (oxalate). Kidney stone patients. Immunosuppressants [1].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Hot water extract', 'common', 'Extracts water-soluble polysaccharides (beta-glucans). Most common preparation [1].'] | Standard | Check label | |
| ['Dual extract (water + alcohol)', 'preferred', 'Also captures betulinic acid and other triterpenes. More complete profile [1].'] | Standard | Check label | |
| ['Raw chaga chunks/powder', '', 'For tea decoction. Traditional Russian preparation [1].'] | Standard | Check label |
3 Common questions
Is chaga the most powerful antioxidant? ▼
It has the highest ORAC score measured, but ORAC is an in vitro assay that does not predict in vivo benefit [2]. ORAC was abandoned as a measure by the USDA in 2012 because it didn't correlate with health outcomes. Chaga's antioxidant potential is real but unproven in humans.
Are there any human studies on chaga? ▼
Essentially none. Despite enormous popularity and impressive preclinical data, chaga lacks human clinical trials [1]. This is a major gap — claims of human health benefits are based entirely on extrapolation from in vitro and animal studies.
Is chaga safe to drink daily? ▼
The major concern is oxalate content — chaga tea from raw chunks can provide very high oxalate loads, contributing to kidney stone risk. One case report described chaga-induced oxalate nephropathy [1]. Extracts with reduced oxalate are preferable for regular use.
Why does chaga grow on birch? ▼
Chaga is a parasitic fungus specific to birch trees. It incorporates betulinic acid from birch bark — this compound has anti-cancer and anti-viral properties. Only birch-grown chaga contains significant betulinic acid [1].
4 Clinical evidence
Strong
Highest ORAC score measured: extraordinary in vitro antioxidant capacity [2]. Betulinic acid has validated anti-cancer, anti-inflammatory, and antiviral properties in preclinical models [1]. Beta-glucan immunostimulation [1]. HIGH
Moderate
Anti-inflammatory: reduced markers in animal models [1]. Anti-tumor: betulinic acid induces apoptosis in cancer cell lines [1]. Antiviral: activity against influenza, HIV, HSV in vitro [1]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Relative
⚠ Kidney stones or oxalate nephropathy — chaga is very high in oxalate (important)
⚠ Bleeding disorders/anticoagulants — possible antiplatelet effect
⚠ Diabetes — may lower blood glucose
⚠ Pregnancy and lactation — insufficient safety data
🚩 Red flags
● Daily raw chaga tea drinker with rising creatinine — oxalate nephropathy [1]
● Patient citing ORAC score as evidence — ORAC doesn't predict health outcomes [2]
● Patient using chaga for cancer treatment — no human evidence [1]
6 Interactions
Drug interactions
Anticoagulants Moderate
Mechanism: Possible antiplatelet effects. [1]
Effect: Theoretical bleeding risk. [1]
Action: Monitor [1].
Insulin/diabetes medications Moderate
Mechanism: Blood glucose lowering in animal studies. [1]
Effect: Theoretical hypoglycemia. [1]
Action: Monitor glucose [1].
Supplement synergies
Other medicinal mushrooms (Reishi, Turkey Tail) · Standard doses of each
Different bioactive profiles; comprehensive mushroom stack [1].
Different bioactive profiles; comprehensive mushroom stack [1].
7 Regulatory
Russia: Traditional medicine. Listed in Russian State Pharmacopoeia [1].
United States (FDA): Dietary supplement. No health claims [1].
Finland/Scandinavia: Traditional wild-harvested product. Growing commercial cultivation [1].
South Korea: Available as supplement.
8 US supplement products
29
on-market products containing Chaga (NIH DSLD)
Brands carrying Chaga (19)
Click a brand to see its Chaga products.
9 Frequently paired with
10 Cite this page
Vancouver: Pkhakadze G. Chaga — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Aug 15]. Available from: https://supplement.ge/ingredients/chaga/
APA 7th: Pkhakadze, G. (2026). Chaga — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/chaga/
📋 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: 2 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. "Chaga — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/chaga/ 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