Botanicals

Green Tea Extract — timing, dose & interactions

Concentrated catechins (EGCG) from green tea, often with caffeine. Rare but serious liver injury has been reported with extract capsules.

Also known as EGCG

Timing

When to take it

Always with food — liver injury has mostly been linked to concentrated extracts on an empty stomach.

Dose note. EFSA found liver risk from ≥800 mg EGCG/day in supplements. Check EGCG and caffeine per serving.

Interactions

Green Tea Extract with other supplements

Safety

Medications & health conditions

NoteBlood pressure medication

Green tea reduces nadolol levels. High doses of green tea lowered blood levels of the beta-blocker nadolol.

Strong evidence
CautionCancer treatment

Green tea extract and bortezomib. EGCG blocked the cancer drug bortezomib in lab studies. Avoid during treatment unless your oncologist agrees.

Animal / lab only
CautionPregnant or breastfeeding

Concentrated green tea in pregnancy. Catechins may reduce folate availability, and extracts add caffeine. Avoid concentrated extracts.

Human data
CriticalLiver disease

Green tea extract has caused liver injury. Liver injury, sometimes severe, has been reported mainly with extract capsules. Avoid with liver disease.

Human data

Buying guide

What to look for on the label

  • Green Tea Extract

    • Label states EGCG and caffeine per serving
    • Decaffeinated if stacking with coffee

FAQ

Common questions

When is the best time to take Green Tea Extract?

Breakfast or Lunch. Always with food — liver injury has mostly been linked to concentrated extracts on an empty stomach.

Should Green Tea Extract be taken with food?

Yes. Taking it with a meal reduces stomach upset.

Can you take Green Tea Extract with Iron?

Separate them by at least 2 hours. Keep green tea extract at least 2 hours away from iron supplements.

Can you take Green Tea Extract with Caffeine?

Yes, but count the caffeine in the extract toward your daily total. Check the label; choose a decaffeinated extract if you already drink coffee.

Sources

References

  1. 01NIH NCCIH — Green Tea