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 Green Tea Extract + Oligonol (Lychee Polyphenol) pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Supplement × Supplement·a caution·Moderate evidence

Green Tea Extract + Oligonol (Lychee Polyphenol)

Q: Can I take Green Tea Extract and Oligonol (Lychee Polyphenol) together?

Possibly, but with caution. Green Tea Extract and Oligonol (Lychee Polyphenol) have a documented caution-tier interaction. Both Oligonol and green tea extract are concentrated polyphenol products; stacking high doses adds to total polyphenol and, with green tea, catechin load, which can compound gut iron binding and theoretical hepatic burden from very high catechin intake.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored caution row.

Caution Moderate evidence

Both Oligonol and green tea extract are concentrated polyphenol products; stacking high doses adds to total polyphenol and, with green tea, catechin load, which can compound gut iron binding and theoretical hepatic burden from very high catechin intake.

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

Green Tea Extract and Oligonol (Lychee Polyphenol)

Pair type

Caution

Evidence

Moderate

Source citations

Scope

Supplement × Supplement

Last verified

June 4, 2026

CautionModerate evidence

What is happening. Both Oligonol and green tea extract are concentrated polyphenol products; stacking high doses adds to total polyphenol and, with green tea, catechin load, which can compound gut iron binding and theoretical hepatic burden from very high catechin intake.

Mechanism. Additive proanthocyanidin and catechin exposure increases non-heme iron chelation; high-dose green tea catechins (EGCG) carry a separate, dose-related hepatotoxicity signal that is not offset by Oligonol.

Recommendation. Use moderate, label-recommended doses of each rather than stacking multiple high-dose polyphenol concentrates. Take both away from iron supplements, and avoid high-dose green tea extract on an empty stomach.

Stack Score

How it moves the number.

Effect on the composite score

If both Green Tea Extract and Oligonol (Lychee Polyphenol) 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

1Oketch-Rabah HA, et al. United States Pharmacopeia safety review of green tea extract and hepatotoxicity. Toxicology Reports. 2020.Needs sourceNo link

Check your full routine

One pair was the worked example.

Drop your supplements and prescriptions into NutriStack and it runs every pair at once: every interaction, synergy, timing rule, and contraindication, each linked to its primary source.

Open the interaction checker → Browse the research index