Does Grapefruit Affect Grape Seed Extract?

May affect absorption or how you feel

The short answer

Grape seed proanthocyanidins inhibit CYP3A4 and P-glycoprotein. Combined with grapefruit, additive enzyme inhibition may occur.

How to arrange timing

Separate grape seed extract from grapefruit by 2 hours.

Reference

Reference noted for this food and supplement combination: Examine.com; Wanwimolruk et al., Clin Exp Pharmacol Physiol 2006

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.