Does Grapefruit Affect Caffeine?

May affect absorption or how you feel

The short answer

Caffeine is metabolized by CYP1A2. Grapefruit's naringin mildly inhibits CYP1A2, potentially slowing caffeine clearance and increasing jitteriness.

How to arrange timing

If sensitive to caffeine, separate from grapefruit by 2 hours.

Reference

Reference noted for this food and supplement combination: Fuhr & Kummert, Clin Pharmacol Ther 1995

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.