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Does Grapefruit Affect Quercetin?
May affect absorption or how you feel
The short answer
Quercetin inhibits CYP3A4 and P-glycoprotein similar to grapefruit. Combined intake may cause additive enzyme/transporter inhibition.
How to arrange timing
Separate quercetin from grapefruit by 2 hours if taking other CYP3A4-metabolized supplements.
Reference
Reference noted for this food and supplement combination: Choi et al., Arch Pharm Res 2011; 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.