Green Tea Extract
Camellia sinensis
Also known as: Camellia sinensis extract, GTE, Green Tea Polyphenols, EGCG, Tea Catechins
Evidence Strength: MODERATE
This ingredient receives a unclassified risk score due to safety concerns identified by health authorities in USA. Scientific evidence indicates green Tea Extract exerts its effects primarily through its high content of…. Reported adverse effects include nausea and headache.
Safety Profile
Common Adverse Effects
- Nausea
- headache
- dizziness
- insomnia
- gastrointestinal upset
Serious Adverse Effects
- Hepatotoxicity
- tachycardia
- hypertension
- allergic reactions
Contraindications
- Liver disease
- cardiovascular disorders
- anxiety disorders
- insomnia
- People taking Warfarin
Interactions
| Drug / Nutrient | Interaction Mechanism | Warning |
|---|---|---|
| Warfarin | may increase bleeding risk — monitor INR closely. Beta | blockers: may reduce efficacy — adjust dose as needed. Antidepressants: may increase stimulant effects — use with caution. Statins: may enhance lipid-lowering effects — monitor lipid levels. Anticoagulants: increased bleeding risk — consider alternative therapies. |
Evidence and Scientific Findings
Ingredient Overview
Biological and Chemical Classification
- Chemical Class
- Polyphenol
- Biological Class
- Antioxidant
- Natural Source
- Camellia sinensis leaves
- Scientific Name
- Camellia sinensis
- Chemical Formula
- C22H18O11
- CAS Number
- 84650-60-2
Mechanism of Action
Clinical Evidence of Effectiveness
| Indication | Evidence Level | Summary |
|---|---|---|
| General | Moderate | Clinical studies on Green Tea Extract have shown mixed results. Some randomized controlled trials suggest benefits in weight management and cardiovascular health, particularly in reducing LDL cholesterol levels. However, the evidence is inconsistent, with some studies showing minimal or no effect. The quality of studies varies, with some lacking rigorous design or having small sample sizes, leading to moderate confidence in the overall conclusions. |
Pharmacokinetics
Recommended Dosage
| Condition / Use | Typical Dose |
|---|---|
| Weight management | 300-600 mg per day. Cardiovascular health: 250-500 mg per day. Antioxidant support: 200-400 mg per day. |
Dosage ranges are based on clinical studies and commonly used supplement formulations. Individual requirements may vary.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Green Tea Extract is derived from the leaves of the Camellia sinensis plant.
- Evidence consistency: High consistency across studies (100%)
- Green Tea Extract is generally considered safe for most adults when used at recommended dosages. However, there are reports of liver toxicity, particularly at high doses or with concentrated extracts. Caution is advised in individuals with liver disease, and it is not recommended for use during pregnancy or breastfeeding. Regulatory agencies have issued warnings about potential liver damage, urging consumers to adhere to dosage guidelines.
- USA/FDA — Approved
The available scientific evidence for Green Tea Extract indicates notable safety signals that warrant caution. Use should be considered carefully and monitored, particularly in sensitive populations or alongside other medications.
Total SETI Score
High risk| Evidence quality | 10/40 |
| Evidence consistency | 20/20 |
| Safety signals | 0/20 |
| Study recency | 10/10 |
| Evidence transparency | 10/10 |
Evidence Summary
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or systematic review)
- 0 studies identified benefits or no safety concern (GREEN)
- 10 studies reported limited or advisory safety evidence (YELLOW)
Evidence Policy
Only peer-reviewed scientific literature indexed in PubMed or comparable databases is included in this evaluation. Commercial websites, blogs, and marketing materials are excluded. All references include direct traceable links to source documents.
Last updated: 06 მარ 2026, 12:01
Evidence Distribution
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Observational / other LOW evidence YELLOWTea Quality Alterations Arising from Plant Diseases: Molecular Pathogenesis and Noncoding Ribonucleic Acid-Driven Host-Pathogen Communication. ↗Naz M et al.. Tea Quality Alterations Arising from Plant Diseases: Molecular Pathogenesis and Noncoding Ribonucleic Acid-Driven Host-Pathogen Communication.. J Agric Food Chem. 2026. PMID:41774081.PMID 41774081 ↗Journal J Agric Food ChemYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41774081/
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Observational / other LOW evidence YELLOWMineral infusion and in-vitro bioaccessibility in Camellia sinensis and herbal tea: influence of matrix and brewing format. ↗Apaydu0131n H. Mineral infusion and in-vitro bioaccessibility in Camellia sinensis and herbal tea: influence of matrix and brewing format.. Front Nutr. 2026. PMID:41769663.PMID 41769663 ↗Journal Front NutrYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41769663/
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Observational / other LOW evidence YELLOWUnveiling the potential of apigenin and kaempferol against colon cancer: an integrated network pharmacology and docking approach. ↗Selvakumar A et al.. Unveiling the potential of apigenin and kaempferol against colon cancer: an integrated network pharmacology and docking approach.. Front Bioinform. 2026. PMID:41768980.PMID 41768980 ↗Journal Front BioinformYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41768980/
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Observational / other LOW evidence YELLOWEffects of Photoperiod on Anthocyanin Biosynthesis-Related Gene Expression and Enzymatic Activity in Purple-Leaf Tea Plants (Camellia sinensis). ↗Li W et al.. Effects of Photoperiod on Anthocyanin Biosynthesis-Related Gene Expression and Enzymatic Activity in Purple-Leaf Tea Plants (Camellia sinensis).. Int J Mol Sci. 2026. PMID:41752001.PMID 41752001 ↗Journal Int J Mol SciYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41752001/
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Observational / other LOW evidence YELLOWOak (Quercus petraea) Leaf-Based Kombucha: A Sustainable Approach to Fermented Beverages. ↗Pencak T et al.. Oak (Quercus petraea) Leaf-Based Kombucha: A Sustainable Approach to Fermented Beverages.. Foods. 2026. PMID:41750899.PMID 41750899 ↗Journal FoodsYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41750899/
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Observational / other LOW evidence YELLOWIntercropping tea plants with different leguminous green manures enhances soil nutrient availability, thereby reshaping the structure and functional potential of soil microbial… ↗Liu Q et al.. Intercropping tea plants with different leguminous green manures enhances soil nutrient availability, thereby reshaping the structure and functional potential of soil microbial communities.. Front Microbiol. 2026. PMID:41743141.PMID 41743141 ↗Journal Front MicrobiolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41743141/
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Observational / other LOW evidence YELLOWIntegrative analysis of endogenous phytohormones and transcriptomics reveals mechanism of light-induced callus formation in tea (Camellia sinensis) cuttings. ↗Gao Y et al.. Integrative analysis of endogenous phytohormones and transcriptomics reveals mechanism of light-induced callus formation in tea (Camellia sinensis) cuttings.. BMC Plant Biol. 2026. PMID:41742034.PMID 41742034 ↗Journal BMC Plant BiolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41742034/
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Observational / other LOW evidence YELLOWLong non-coding RNA Cslnc256 regulates tea plant resistance to anthracnose by suppressing CsmiR395-mediated sulfate metabolism. ↗Jiang T et al.. Long non-coding RNA Cslnc256 regulates tea plant resistance to anthracnose by suppressing CsmiR395-mediated sulfate metabolism.. Plant J. 2026. PMID:41723861.PMID 41723861 ↗Journal Plant JYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41723861/
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Observational / other LOW evidence YELLOWFluoride detoxification in tea plants depends on aluminium and localization in the epidermis. ↗Zhang C et al.. Fluoride detoxification in tea plants depends on aluminium and localization in the epidermis.. Plant Physiol. 2026. PMID:41722032.PMID 41722032 ↗Journal Plant PhysiolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41722032/
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Observational / other LOW evidence YELLOWCamellia sinensis-synthesized silver nanoparticles and meropenem combination against extensively drug-resistant Klebsiella pneumoniae. ↗Elmasry EM et al.. Camellia sinensis-synthesized silver nanoparticles and meropenem combination against extensively drug-resistant Klebsiella pneumoniae.. Sci Rep. 2026. PMID:41720838.PMID 41720838 ↗Journal Sci RepYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41720838/
Score Transparency
0 of 10 approved references (score saturates at 10). More peer-reviewed studies = stronger evidence base.
Method: Q = number of approved references ÷ 10 (capped at 1.0)
Limited — mostly case reports or animal studies
Method: L = mean study-level weight across approved references. Level 1 (meta-analysis / systematic review) = 1.0; Level 2 (RCT) = 0.8; Level 3 (cohort/case-control) = 0.6; Level 4 (case report) = 0.4; Level 5 (animal / in-vitro) = 0.2.
Mixed or neutral — roughly equal benefit and risk signals
Method: D = (sum of risk-scored references − sum of benefit-scored references) ÷ total evidence score, then scaled from [−1, 1] to [0, 1]. 0.0 = pure benefit; 0.5 = neutral; 1.0 = pure risk.
Multiple active safety or regulatory signals
Method: S = 0.5 (neutral baseline) + sum of active signal severity deltas ÷ 10. Severity deltas: Critical = +2.0, High = +1.5, Moderate = +1.0, Low = +0.5. Capped at 1.0.
Final GIRI Score for Green Tea Extract. Risk level thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
Full methodology & data sources
The GIRI Score is computed entirely from structured data — no editorial scoring or subjective weighting is applied at any step.
- References: Only approved references are counted. Each reference is assigned an evidence level (L1–L5) and a direction (risk / neutral / benefit) by the reference manager or AI classifier.
- Safety Signals: Sourced from regulatory agencies (FDA, EMA, Health Canada, TGA, and others) and pharmacovigilance databases. Only active signals count toward the score.
- Formula version: GIRI Score v3.7.0 — Q × L × D × S × 10.
- Limitations: The score reflects published evidence and recorded signals as of the last update date. It is not a clinical risk assessment and should not replace advice from a qualified healthcare professional.
Risk Level Classification
Based on available regulatory signals and scientific evidence, this ingredient presents a moderate safety concern. Caution is advised, particularly at high doses or in sensitive populations.
0–3.0
3.0–5.5
5.5–7.5
7.5–10
The score pin shows exactly where this ingredient falls on the fixed risk scale.
What drove the Moderate classification for Green Tea Extract
A score of 5.0 places this ingredient in the Moderate band. Thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
0 approved references.
Limited — mostly case reports or animal studies (Level 4–5).
Neutral or mixed — benefit and risk signals roughly balanced.
1 active signal (highest severity: High). Each active signal raises S above the neutral baseline of 0.5.
1 jurisdiction has active restrictions or advisories. Regulatory signals are recorded as Safety Signals and raise the S component.
How are the Low / Moderate / High / Critical thresholds defined?
The four risk levels are fixed score bands. A score is assigned to exactly one level based on where it falls:
| Level | Score | Meaning |
|---|---|---|
| LOW | 0.0 – 2.9 | Sparse or predominantly beneficial evidence. No active safety alerts. |
| MODERATE | 3.0 – 5.4 | Mixed signals — some risk alongside benefit. Caution at high doses or in sensitive groups. |
| HIGH | 5.5 – 7.4 | Multiple studies or regulatory alerts documenting adverse effects. Professional oversight recommended. |
| CRITICAL | 7.5 – 10 | Regulatory restrictions in one or more major jurisdictions. Serious documented harm. Avoid without specialist supervision. |
Thresholds are fixed constants (GIRI_Score_Utils::LEVEL_THRESHOLDS). They do not change per ingredient and are never subject to editorial adjustment.


