Does Grapefruit Affect Kava?

Use extra care with this combination

The short answer

Kavalactones are CYP3A4 and CYP2E1 substrates. Grapefruit inhibition increases kava blood levels, compounding the risk of severe hepatotoxicity.

How to arrange timing

Do not consume grapefruit while taking kava. Both carry hepatotoxicity risk; combining amplifies danger.

Reference

Reference noted for this food and supplement combination: Teschke et al., Ann Hepatol 2009; FDA

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.