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Copyright © 2018 Natural Medicines (www.naturalmedicines.com)
August 2018

Statins + St. John’s wort: a big concern?

Most patients taking a statin know that grapefruit can affect how well their statin works. But they might not know that St. John's wort, a popular supplement for depression, can also affect statins. St. John’s wort can affect both the absorption and clearance of some statins.

St. John’s wort is a potent inducer of cytochrome P450 3A4 (CYP3A4) enzyme and of P-glycoprotein. CYP3A4 induction increases how quickly the liver breaks down certain statins. P-glycoprotein induction decreases how well the body absorbs certain statins. Both of these factors can decrease blood levels of statins, including simvastatin, atorvastatin (Lipitor), lovastatin (Mevacor), and rosuvastatin (Crestor). This will likely make these statins less effective, requiring a higher dose. But St. John’s wort doesn’t affect all statins. Statins that aren’t CYP3A4 or P-glycoprotein substrates, including fluvastatin and pravastatin, are unlikely to be affected by St. John’s wort.

For details about other potential statin-supplement interactions, check out our interactions checker.

The information in this brief report is intended for informational purposes only, and is meant to help users better understand health concerns. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions. Copyright © 2018 Natural Medicines Inc. Commercial distribution or reproduction prohibited. Natural Medicines is the leading provider of high-quality, evidence-based, clinically-relevant information on natural medicine, dietary supplements, herbs, vitamins, minerals, functional foods, diets, complementary practices, CAM modalities, exercises and medical conditions. Monograph sections include interactions with herbs, drugs, foods and labs, contraindications, depletions, dosing, toxicology, adverse effects, pregnancy and lactation data, synonyms, safety and effectiveness.