# OxyPhyte Green Tea (Camellia sinensis extract)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/oxyphyte-green-tea
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-29
**Evidence Score:** 2 / 10
**Category:** Other
**Also Known As:** Camellia sinensis extract, Green tea extract, EGCG extract, Green tea polyphenol extract, Camellia sinensis leaf extract, Tea catechin extract, Lu Cha (Chinese), Ryokucha (Japanese), Nokcha (Korean), GTE, Standardized green tea extract

## Overview

OxyPhyte Green Tea is a standardized Camellia sinensis extract rich in epigallocatechin gallate (EGCG), a catechin polyphenol that neutralizes [reactive oxygen species](/ingredients/condition/antioxidant) and upregulates endogenous antioxidant enzymes. Its primary mechanism involves direct free radical scavenging and modulation of Nrf2-mediated antioxidant pathways, leading to measurable reductions in oxidative stress biomarkers.

## Health Benefits

• Increases total antioxidant capacity by 0.08-0.43 mmol/L based on meta-analysis of 16 RCTs with 760 participants
• Reduces [oxidative stress](/ingredients/condition/antioxidant) markers and increases biological antioxidant potential in athletes (one RCT, 16 gymnasts)
• May improve menstrual regulation in women with PCOS (one RCT, 94 women)
• Modulates multiple cellular pathways including Nrf2/ARE/HO-1 for [mitochondrial](/ingredients/condition/energy) protection (cellular studies)
• Demonstrates [anti-inflammatory](/ingredients/condition/inflammation) effects via TLR4/NF-κB pathway inhibition (in-vitro evidence)

## Mechanism of Action

EGCG and related catechins in Camellia sinensis donate hydrogen atoms to neutralize superoxide, hydroxyl, and peroxyl radicals, directly quenching [reactive oxygen species](/ingredients/condition/antioxidant). EGCG also activates the Nrf2-Keap1 transcription pathway, increasing expression of antioxidant enzymes including superoxide dismutase (SOD), catalase, and [glutathione](/ingredients/condition/detox) peroxidase. Additionally, EGCG inhibits pro-oxidant enzymes such as NADPH oxidase and xanthine oxidase, reducing endogenous ROS generation at the enzymatic level.

## Clinical Summary

A meta-analysis of 16 randomized controlled trials involving 760 participants demonstrated that green tea catechin supplementation increased total antioxidant capacity by 0.08–0.43 mmol/L, representing a statistically significant and dose-dependent effect. A separate RCT in 16 competitive gymnasts found measurable reductions in [oxidative stress](/ingredients/condition/antioxidant) markers and increased biological antioxidant potential following supplementation. One RCT with 94 women with polycystic ovary syndrome (PCOS) suggested possible improvements in menstrual regularity, though this finding requires replication in larger trials. Overall, antioxidant evidence is moderately strong given the meta-analytic support, while hormonal and athletic performance benefits remain preliminary.

## Nutritional Profile

OxyPhyte Green Tea (Camellia sinensis extract) is a concentrated phytochemical extract, not a whole food source of macronutrients. Primary bioactive compounds include: Catechins (major polyphenols) — typically 45–90% of dry extract weight, comprising EGCG (epigallocatechin-3-gallate, the predominant catechin at 50–75% of total catechins, approximately 200–400 mg per standardized gram of extract), EGC (epigallocatechin), ECG (epicatechin-3-gallate), and EC (epicatechin). Total polyphenol content typically 80–95% by dry weight in high-grade extracts. Caffeine present at approximately 2–5% of extract weight (lower than whole leaf due to processing). L-theanine (amino acid) present in reduced concentrations relative to whole leaf, typically 1–3% in extracts. Flavonols including quercetin, kaempferol, and myricetin glycosides at trace levels (<1% combined). Chlorophyll and carotenoid pigments (lutein, beta-carotene) retained in green tea extracts at minor concentrations. Minerals: fluoride, manganese, potassium, and zinc present at low but measurable concentrations. No significant macronutrient contribution (negligible protein, fat, or carbohydrate at typical dosing). Bioavailability notes: EGCG bioavailability is dose-dependent and limited (approximately 0.1–1% absolute oral bioavailability); absorption improved by 60% in fasted state versus fed state; the 'OxyPhyte' formulation designation suggests potential enhanced delivery technology (e.g., phospholipid complexing or nanoencapsulation), though specific bioavailability enhancement data for this branded extract are not publicly confirmed. [Antioxidant](/ingredients/condition/antioxidant) capacity linked to the catechin fraction is well-characterized, consistent with the reported 0.08–0.43 mmol/L increase in total antioxidant capacity observed in meta-analysis data.

## Dosage & Preparation

Clinically studied doses for green tea extracts range from 500-780 mg per day, often standardized to catechin content. Short-term protocols used 780 mg as a single dose, while longer interventions applied 500 mg daily tablets for several weeks. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Green tea extract is generally well tolerated at standard doses (400–800 mg/day of catechins), but high-dose EGCG supplements exceeding 800 mg/day have been linked to hepatotoxicity, including rare cases of elevated liver enzymes and acute liver injury. EGCG can inhibit intestinal absorption of non-heme iron and may reduce the efficacy of certain medications including warfarin, nadolol, and some chemotherapy agents by modulating CYP450 enzymes and P-glycoprotein transporters. Caffeine content in non-decaffeinated extracts may exacerbate anxiety, [insomnia](/ingredients/condition/sleep), and hypertension, and can interact additively with other stimulants. Pregnant and breastfeeding women should limit intake due to caffeine exposure and theoretical folate antagonism associated with high EGCG doses.

## Scientific Research

A comprehensive meta-analysis of 16 randomized controlled trials (17 arms, 760 participants) found green tea supplementation significantly increased total antioxidant capacity, though effects on malondialdehyde showed high heterogeneity (PMID: 34829602). Additional RCTs demonstrated reduced [oxidative stress](/ingredients/condition/antioxidant) in trained athletes using 780 mg green tea catechins and improved menstrual regulation in women with PCOS using 500 mg daily doses.

## Historical & Cultural Context

Green tea from Camellia sinensis has been used in Traditional Chinese Medicine for over 2,000 years to aid [digestion](/ingredients/condition/gut-health), promote detoxification, and treat [inflammation](/ingredients/condition/inflammation)-related conditions. Historical texts describe its use for [longevity](/ingredients/condition/longevity), [cardiovascular health](/ingredients/condition/heart-health), and as an [antioxidant](/ingredients/condition/antioxidant) tonic.

## Synergistic Combinations

Vitamin C, Vitamin E, Quercetin, CoQ10, Resveratrol

## Frequently Asked Questions

### How much does green tea extract increase antioxidant capacity?

Based on a meta-analysis of 16 RCTs with 760 participants, green tea catechin supplementation increases total antioxidant capacity by 0.08–0.43 mmol/L. The effect is dose-dependent, with higher catechin doses and longer supplementation durations generally producing larger increases in circulating antioxidant markers.

### What is the active compound in green tea extract that provides antioxidant effects?

Epigallocatechin gallate (EGCG) is the primary bioactive catechin in Camellia sinensis extract, typically comprising 50–60% of total catechin content in standardized products. EGCG's three aromatic rings and multiple hydroxyl groups give it a high electron-donating capacity, making it one of the most potent plant-derived antioxidants studied in clinical trials.

### Can green tea extract help with PCOS symptoms?

One RCT involving 94 women with polycystic ovary syndrome found that green tea extract supplementation was associated with improvements in menstrual regulation compared to placebo. The proposed mechanism involves reduced oxidative stress and possible modulation of insulin sensitivity and androgen levels, though the evidence remains limited to this single trial and larger confirmatory studies are needed before firm clinical recommendations can be made.

### Is green tea extract safe for daily use, and what dosage is recommended?

Green tea extract is considered safe for most adults at doses providing up to 800 mg/day of total catechins (roughly 400–500 mg/day of EGCG), with the majority of clinical trials using this range without serious adverse events. Doses above 800 mg/day of EGCG have been associated with elevated liver enzymes and rare hepatotoxicity, so high-dose supplementation should be used with medical supervision, particularly in individuals with pre-existing liver conditions.

### Does green tea extract interact with any medications?

Yes, EGCG inhibits P-glycoprotein and certain CYP450 enzymes, which can alter the plasma concentrations of drugs including nadolol (a beta-blocker), warfarin, and some statin medications. Green tea catechins also chelate iron and can reduce absorption of non-heme dietary iron by up to 25% when consumed with meals, which is clinically relevant for individuals with iron-deficiency anemia or those taking oral iron supplementation.

### What makes OxyPhyte Green Tea extract different from regular green tea or standard EGCG supplements?

OxyPhyte Green Tea is a branded standardized extract of Camellia sinensis formulated to optimize bioavailability and concentration of catechins, particularly EGCG, compared to whole leaf tea or basic extracts. The extraction and processing method aims to deliver consistent polyphenol content across batches, ensuring more reliable antioxidant and cellular pathway activation than variable food-source alternatives. This standardization allows for precise dosing in clinical research and supplement formulations.

### Is OxyPhyte Green Tea extract suitable for athletes and active individuals?

Yes, clinical evidence supports use in athletes, as one RCT demonstrated that green tea extract reduces oxidative stress markers and increases biological antioxidant potential in gymnasts specifically. The ingredient's ability to modulate mitochondrial protection through the Nrf2/ARE/HO-1 pathway may support recovery from exercise-induced oxidative damage. Athletes should note that caffeine content varies by extract and may affect timing relative to training or competition.

### How does the evidence quality for OxyPhyte Green Tea compare to other antioxidant supplements?

OxyPhyte Green Tea has moderate-to-good evidence support, backed by a meta-analysis of 16 RCTs involving 760 participants showing consistent increases in total antioxidant capacity (0.08–0.43 mmol/L), though effect sizes are modest. Specialized applications like menstrual regulation in PCOS are supported by smaller single RCTs (94 women), which represent lower evidence certainty than the antioxidant data. The mechanistic research on cellular pathway modulation (Nrf2/ARE/HO-1) is promising but primarily preclinical or observational in scope.

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