EGCG (GREEN TEA EXTRACT)
What Is EGCG (GREEN TEA EXTRACT)?
EGCG (Epigallocatechin-3-gallate) is the primary bioactive catechin polyphenol found in green tea extract, comprising approximately 50-80% of total catechins. It functions as a potent antioxidant, iron chelator, and has demonstrated effects on metabolism, cellular signaling pathways, and mitochondrial function. EGCG is primarily used for weight management, metabolic health, antioxidant support, and potential cognitive and cardiovascular benefits.
EGCG (GREEN TEA EXTRACT) Research & Studies
01 Therapeutic effect of high-dose green tea extract on weight reduction: A randomized, double-blind, placebo-controlled clinical trial ▸
High-dose EGCG (856.8 mg daily) demonstrated significant effects on weight reduction and metabolic parameters in women with central obesity over 12 weeks in a controlled clinical trial.
View Study (PubMed)02 Anti-Fatigue Effect of Green Tea Polyphenols (-)-Epigallocatechin-3-Gallate (EGCG) ▸
EGCG supplementation (50-200 mg/kg) significantly prolonged exhaustive swimming time in mice, decreased lactate and oxidative stress markers, and increased glycogen stores and antioxidant enzyme activities.
View Study (PubMed)03 Hepatotoxicity with High-Dose Green Tea Extract: Effect of Catechol-O-Methyltransferase and Uridine 5'-Diphospho-glucuronosyltransferase 1A4 Genotypes ▸
Long-term high-dose GTE supplementation (843 mg/day EGCG) showed genotype-dependent effects on liver enzyme markers, with certain COMT and UGT1A4 variants associated with increased liver injury risk.
View Study (PubMed)04 Investigating the Immune Basis of Green Tea Extract Induced Liver Injury in Healthy Donors Expressing HLA-B*35:01 ▸
EGCG was shown to activate T-cells in vitro, suggesting immune-mediated mechanisms may contribute to rare cases of green tea extract-induced liver injury, particularly in individuals with specific HLA variants.
View Study (PubMed)05 Safety assessment of green tea based beverages and dried green tea extracts as nutritional supplements ▸
Green tea beverages providing up to 450mg EGCG daily are considered safe based on historical use, but concentrated extracts in supplement form require caution due to potential hepatotoxicity at doses exceeding 800mg EGCG daily.
View Study (PubMed)06 Green tea extract modulates oxidative tissue injury in beta-thalassemic mice by chelation of redox iron and inhibition of lipid peroxidation ▸
GTE rich in EGCG demonstrated iron-chelating properties and reduced oxidative stress markers in iron-overloaded mice, suggesting potential therapeutic applications in conditions involving iron overload.
View Study (PubMed)07 Decaffeinated green tea extract rich in epigallocatechin-3-gallate improves insulin resistance and metabolic profiles in normolipidic diet--but not high-fat diet-fed mice ▸
EGCG-rich green tea extract improved insulin sensitivity and metabolic markers in normal-weight mice but was ineffective in high-fat diet-fed obese mice, suggesting context-dependent efficacy.
View Study (PubMed)08 Modified (-)-gallocatechin gallate-enriched green tea extract rescues age-related cognitive deficits by restoring hippocampal synaptic plasticity ▸
Modified GCG-enriched green tea extract improved age-related cognitive impairments and restored long-term synaptic plasticity in aged mice, suggesting potential neuroprotective benefits.
View Study (PubMed)EGCG (GREEN TEA EXTRACT) User Reviews & Experiences
*Based on large scale analysis of publicly available user experiences
User experiences with EGCG are genuinely divided. While some users report benefits for weight management, antioxidant support, and metabolic health, many express significant concerns about liver toxicity, dosing uncertainty, and minimal noticeable effects. The hepatotoxicity warnings and conflicting dosage information create considerable anxiety among users.
EGCG (GREEN TEA EXTRACT) Benefits, Dosage & Side Effects
- Weight Management Support: Users report incorporating EGCG primarily for appetite control and metabolic enhancement during cutting phases, though effectiveness varies significantly between individuals
- Antioxidant Activity: Commonly used as part of longevity and anti-aging protocols, particularly in comprehensive biohacking stacks for cellular health and oxidative stress reduction
- Zinc/Quercetin Synergy: Frequently mentioned as an ionophore for zinc absorption, particularly during viral illness protocols alongside quercetin for immune support
- Serotonin Regulation: Often paired with 5-HTP to prevent peripheral serotonin conversion, allowing more effective blood-brain barrier crossing for mood enhancement
- Context-Dependent Results: EGCG appears more effective for metabolic support in lean individuals rather than those with significant obesity, with minimal noticeable effects reported by many users taking it in isolation
- Stacking Requirements: Most positive reports involve EGCG as part of larger supplement protocols rather than standalone use, suggesting synergistic effects are important for perceivable benefits
- Individual Variation: Genetic factors (COMT, UGT1A4) significantly influence both efficacy and safety, with some users experiencing benefits while others report no effects or adverse reactions
- Dosage Sensitivity: Effectiveness appears highly dose-dependent, with a narrow window between ineffective low doses and potentially hepatotoxic high doses creating challenges for optimal use
- Standard Daily Dose: Most users report taking 100-400mg EGCG daily from standardized extracts (typically 45-98% EGCG concentration), often split into multiple doses
- High-Dose Protocols: Research-backed weight loss protocols use 800-850mg daily, though users express significant concern about liver toxicity at these levels
- Safety Threshold: Community consensus suggests staying below 400mg EGCG daily for long-term use, with many recommending 200-300mg as optimal risk-benefit balance
- Cycling Recommendations: Some experienced users suggest cycling EGCG rather than continuous daily use to minimize hepatotoxicity risk, though specific protocols vary
- Liver Toxicity Concerns: Hepatotoxicity is the most frequently mentioned concern, with users reporting elevated liver enzymes, pain in liver area, and anxiety about long-term damage, especially at doses above 400mg daily
- Digestive Issues: Reports of stomach discomfort, bloating, and gastrointestinal distress when taken on empty stomach or in high doses
- Sleep Disturbances: Some users report vivid dreams, night terrors, or disrupted sleep patterns when taking EGCG, particularly in evening doses
- Anxiety and Mood Effects: Reports of increased anxiety, depressive crashes 2-3 hours after dosing, and general mood instability in sensitive individuals
- Widely Available Brands: NOW Foods, Pure Encapsulations, Nootropics Depot, and Swanson frequently mentioned as trusted sources, with emphasis on third-party testing and standardized EGCG content
- Powder vs Capsules: Bulk powder from vendors like Powder City offers significantly lower cost (2-3 cents per dose for 45% EGCG powder) compared to branded capsules, though dosing accuracy requires precision
- Quality Concerns: Users emphasize importance of decaffeinated extracts, standardized EGCG percentage, and avoiding products with maltodextrin or excessive fillers to minimize side effects
Community Reviews
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