NutriDex

The Supplement Research Compendium

Supplement–drug interactions

Supplements That Interact with CYP3A4 drugs (some statins, CCBs, immunosuppressants)

5 supplements in NutriDex have a known or theoretical interaction with cyp3a4 drugs (some statins, ccbs, immunosuppressants), including 1 best avoided entirely. Grouped by severity below; each links to its full evidence, dosing & mechanism. This is educational and not exhaustive — always tell your doctor or pharmacist about every supplement you take before combining it with medication.

Avoid — do not combine 1

Grapefruit

Grapefruit can sharply raise levels of simvastatin/atorvastatin and other CYP3A4 drugs — toxicity risk.

Caution — use only with medical guidance 2

Pomelo

Pomelo, a grapefruit relative, can similarly raise levels of CYP3A4 drugs; treat like grapefruit.

St. John's Wort

Can reduce blood levels and effectiveness of a wide range of CYP3A4-metabolized medicines.

Monitor — watch for effects 2

Citrus Bergamot

As a citrus product, bergamot may mildly affect CYP3A4-metabolized drug levels; monitor for side effects.

Quercetin

May alter blood levels of CYP3A4/P-gp drugs such as cyclosporine; monitor levels and effects.

Each supplement links to its full evidence, dosing, mechanism & citations. See also all medication interaction guides →