What kind of interaction is it?

Caution: an interaction that may reduce efficacy or raise side-effect risk and warrants monitoring.

Is this interaction backed by published research?

Yes. NutriStack lists 1 citation row for the EGCG (Epigallocatechin Gallate) + Green Tea Extract pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Supplement × Supplement·a caution·Moderate evidence

EGCG (Epigallocatechin Gallate) + Green Tea Extract

Q: Can I take EGCG (Epigallocatechin Gallate) and Green Tea Extract together?

Possibly, but with caution. EGCG (Epigallocatechin Gallate) and Green Tea Extract have a documented caution-tier interaction. EGCG is the principal catechin in green tea extract, so combining a standalone EGCG product with green tea extract stacks the same compound and substantially raises total EGCG exposure.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored caution row.

Caution Moderate evidence

EGCG is the principal catechin in green tea extract, so combining a standalone EGCG product with green tea extract stacks the same compound and substantially raises total EGCG exposure.

Supplement × Supplement

Open the interaction checker → Read the methodology

From the database

What the row says.

Every entry follows the same shape: what is happening, the mechanism, and the recommendation.

Substances

EGCG (Epigallocatechin Gallate) and Green Tea Extract

Pair type

Caution

Evidence

Moderate

Source citations

Scope

Supplement × Supplement

Last verified

June 4, 2026

CautionModerate evidence

What is happening. EGCG is the principal catechin in green tea extract, so combining a standalone EGCG product with green tea extract stacks the same compound and substantially raises total EGCG exposure.

Mechanism. Additive exposure to the same active catechol polyphenol; high-dose EGCG, especially fasted, is associated with idiosyncratic hepatotoxicity.

Recommendation. Do not stack standalone EGCG with green tea extract. Count both toward total daily EGCG and keep the combined dose well below roughly 800 mg/day, taken with food.

Stack Score

How it moves the number.

Effect on the composite score

If both EGCG (Epigallocatechin Gallate) and Green Tea Extract are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).

The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.

Sources

Sources, by evidence tier.

Every claim on this page is cited. PMIDs link straight to PubMed.

Reference material

1Hu J, Webster D, Cao J, Shao A. The safety of green tea and green tea extract consumption in adults - results of a systematic review. Regulatory Toxicology and Pharmacology. 2018.Needs sourceNo link

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