Does Grapefruit Affect Green Tea Extract (EGCG)?

May affect absorption or how you feel

The short answer

EGCG is a CYP3A4 substrate. Grapefruit may increase EGCG blood levels, potentially increasing the risk of liver stress at high doses.

How to arrange timing

Separate green tea extract from grapefruit by 2 hours, especially at high doses.

Reference

Reference noted for this food and supplement combination: Mazzanti et al., Eur J Clin Pharmacol 2009; Examine.com

Important context

The effect can also change with food amount, supplement dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.