Epicatechin gallate
Epicatechin gallate (ECG) is one of four major green-tea catechins, making up ~10–15% of total green-tea catechin content (behind EGCG, the dominant catechin). Stand-alone human ECG research is sparse — almost all the meaningful clinical data are for either whole green tea or EGCG specifically. ECG's mechanisms (antioxidant activity, enzyme inhibition, NF-κB modulation) parallel the other catechins but are individually less validated. For evidence-based use, see whole green tea (/nutrients/camellia-sinensis) or EGCG.
Quick decision guide
May help most
There is no specific clinical indication for stand-alone ECG. People wanting catechin exposure get a balanced dose from brewed green tea (3–4 cups/day delivers ~30–60 mg ECG).
Common dosing range
Brewed green tea: 3–4 cups/day delivers ~30–60 mg ECG plus the other catechins. Standardised green tea extract supplements list total catechin content; ECG fraction is rarely disclosed individually.
When to expect effects
Not established for stand-alone ECG. Green tea extract bioavailability data show catechins reach peak plasma at ~1–2 hours and are cleared within ~6 hours.
Watch out for
Gallated catechins (ECG, EGCG) at high supplement doses on an empty stomach have been linked to idiosyncratic hepatotoxicity. Take with food and don't mega-dose green tea extract.
Evidence snapshot
What is it
Epicatechin gallate (ECG) is one of the major catechins in green tea (Camellia sinensis), structurally related to EGCG and contributing to green tea's polyphenol activity.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
Cardiovascular biomarkers (green tea as a whole) Limited Evidence | Small LDL and BP reductions in green tea meta-analyses; effect size not isolated for ECG | Adults willing to drink 3–5 cups of green tea daily as part of an overall heart-healthy diet | Weeks to months |
Antioxidant capacity (biomarker) Mixed Evidence | Short-term rise in plasma antioxidant capacity after green tea / catechin intake; clinical relevance uncertain | Adults choosing green tea for the broader polyphenol package | Hours for plasma marker changes |
Antimicrobial activity (in vitro) Weak Evidence | Antimicrobial activity in vitro at concentrations not achievable from oral intake | None established clinically | Not established clinically |
Cardiovascular biomarkers (green tea as a whole)
- Effect
- Small LDL and BP reductions in green tea meta-analyses; effect size not isolated for ECG
- Best fit
- Adults willing to drink 3–5 cups of green tea daily as part of an overall heart-healthy diet
- Time
- Weeks to months
Antioxidant capacity (biomarker)
- Effect
- Short-term rise in plasma antioxidant capacity after green tea / catechin intake; clinical relevance uncertain
- Best fit
- Adults choosing green tea for the broader polyphenol package
- Time
- Hours for plasma marker changes
Antimicrobial activity (in vitro)
- Effect
- Antimicrobial activity in vitro at concentrations not achievable from oral intake
- Best fit
- None established clinically
- Time
- Not established clinically
Evidence for 3 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
Cardiovascular biomarkers (green tea as a whole)
Biomarker supportModest meta-analytic evidence supports green tea consumption (3–5 cups/day) for small reductions in LDL-cholesterol, blood pressure, and improved endothelial function. Effects are attributable to total catechin content, with EGCG typically credited as the primary driver; ECG contributes incrementally. The cardiovascular benefit is for green tea drinking, not for taking ECG capsules.
Bottom line: Drink the tea. Don't expect a stand-alone ECG capsule to deliver cardiovascular benefits.
Antioxidant capacity (biomarker)
Biomarker supportGreen tea catechins as a class — including ECG — increase plasma antioxidant capacity in short-term human trials. ECG itself has higher in vitro radical-scavenging capacity than the non-gallated catechins (EC, EGC). Translating this to clinical disease prevention has been inconsistent across hard endpoint trials. Most of the clinical signal in green tea trials is attributable to total catechin content rather than ECG specifically.
Bottom line: Worth getting from green tea, not from an isolated ECG capsule.
Antimicrobial activity (in vitro)
Mechanism onlyECG, like EGCG, inhibits growth of several pathogens (Streptococcus mutans, MRSA, influenza virus) in cell-culture and biofilm assays. It also potentiates β-lactam antibiotics against MRSA in vitro. None of this has translated into human clinical evidence at supplemental doses. The plasma concentrations required to reproduce in-vitro effects are well above what green tea or catechin supplements achieve.
Bottom line: Interesting test-tube biology; don't substitute for evidence-based antimicrobial treatment.
How it works
How to take it
What to track
Bottom line: Get ECG from brewed green tea, not as a standalone supplement. If using a green tea extract, take with food and don't mega-dose.
4 commercial forms
Compare the main delivery options and what they’re best suited for.
Brewed green tea (Camellia sinensis)
Food-form (preferred)Standard whole-leaf or bagged green tea. Delivers a balanced mix of all four major catechins (EGCG, EGC, ECG, EC) plus caffeine, L-theanine, and other minor polyphenols. See /nutrients/camellia-sinensis for the full whole-tea evidence review.
Standard dietary exposure; well-characterised catechin profile.
Green tea extract capsule (mixed catechins)
ConcentratedStandardised extracts deliver 200–400 mg total catechins per serving. ECG component is rarely itemised on the label. Hepatotoxicity case reports motivate taking with food and keeping the total EGCG dose ≤500–700 mg/day.
Higher dose-per-pill than tea; greater hepatotoxicity risk if mega-dosed empty-stomach.
Decaffeinated green tea extract
For caffeine-sensitive adultsSame catechin profile minus most of the caffeine. Useful if you want the catechin exposure without afternoon jitters or insomnia.
Similar catechin profile; caffeine removed.
Isolated epicatechin gallate (research-only)
Not a consumer productPurified ECG is sold to research laboratories for in vitro and mechanistic study. Not a meaningful consumer-supplement category — no clinical-trial evidence supports stand-alone ECG dosing.
Research-grade material; no clinical use case established.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Idiosyncratic hepatotoxicity from high-dose green tea extract — most case reports involve concentrated extracts (often combined with EGCG ≥800 mg/day) taken on an empty stomach. Symptoms include fatigue, nausea, dark urine, jaundice — stop the supplement and check liver enzymes.
Iron-absorption inhibition — high catechin intakes with meals reduce non-heme iron absorption. Important for adults with iron deficiency or pregnant women; separate green tea from iron-rich meals or iron supplements by ~1 hour.
Caffeine effects (jitteriness, palpitations, insomnia) at higher daily green tea intakes — especially in caffeine-sensitive adults.
Who should avoid it
- Anyone with known liver disease or unexplained transaminitis — avoid concentrated green tea extract.
- People taking acetaminophen at high cumulative doses or other potentially hepatotoxic medications — additive risk.
- Pregnant women consuming large amounts of green tea — caffeine intake should stay <200 mg/day in pregnancy, and high catechin intake may interfere with folate.
- People with iron deficiency anaemia — separate green tea from iron-rich meals.
Pregnancy & breastfeeding
Brewed green tea in modest amounts (1–2 cups/day) is generally compatible with pregnancy if total caffeine intake stays under ~200 mg/day. Avoid concentrated green tea extract supplements in pregnancy — catechins may interfere with folate, and hepatotoxicity risk is unwelcome during pregnancy.
Bottom line: Brewed green tea is low-risk for most adults. Concentrated extracts on empty stomach are the main hepatotoxicity setup — take with food, don't mega-dose.
Interactions
Catechins (including ECG) reduce non-heme iron absorption when consumed with the meal. Separate by ~1 hour.
Additive hepatotoxicity potential — particularly with concentrated green tea extracts plus high-dose acetaminophen.
Green tea catechins reduce nadolol absorption (clinically demonstrated). Take green tea ≥3 hours apart from nadolol.
Green tea contains modest vitamin K. Large daily intakes shift INR; keep intake consistent.
Additive caffeine effects (jitteriness, palpitations, BP rise) from green tea's natural caffeine content.
Theoretical additive bleeding risk via mild antiplatelet effect of catechins; rarely clinically meaningful at dietary intakes.
Food sources
| Food | Amount | %DV |
|---|---|---|
| Brewed green tea (Camellia sinensis) | 1 cup / 240 g (~10–15 mg ECG, ~80–100 mg total catechins) | — |
| Matcha (powdered green tea) | 1 tsp (~2 g; ~15–25 mg ECG, ~150–250 mg total catechins — higher than brewed) | — |
| White tea (Camellia sinensis) | 1 cup (~5–10 mg ECG) | — |
| Brewed oolong tea | 1 cup (~3–7 mg ECG — less than green tea due to partial oxidation) | — |
| Brewed black tea | 1 cup (~1–3 mg ECG — most catechins converted to theaflavins / thearubigins during oxidation) | — |
Brewed green tea (Camellia sinensis)
- Amount
- 1 cup / 240 g (~10–15 mg ECG, ~80–100 mg total catechins)
- %DV
- —
Matcha (powdered green tea)
- Amount
- 1 tsp (~2 g; ~15–25 mg ECG, ~150–250 mg total catechins — higher than brewed)
- %DV
- —
White tea (Camellia sinensis)
- Amount
- 1 cup (~5–10 mg ECG)
- %DV
- —
Brewed oolong tea
- Amount
- 1 cup (~3–7 mg ECG — less than green tea due to partial oxidation)
- %DV
- —
Brewed black tea
- Amount
- 1 cup (~1–3 mg ECG — most catechins converted to theaflavins / thearubigins during oxidation)
- %DV
- —
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
Is ECG the same as EGCG?⌄
They are related catechins but distinct molecules. EGCG is more abundant in green tea and more studied.
References by claim
Antioxidant capacity (biomarker)
Safety
Other references
Epicatechin gallate on Wikidata — Wikidata link
Track Epicatechin gallate with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.