Quercetin and CYP Enzymes: How This Flavonoid Affects Drug Metabolism

When you take quercetin, a natural flavonoid found in apples, onions, and berries that’s often used as a supplement for inflammation and allergies. It’s known for its antioxidant properties, but it also interacts with your body’s drug-processing system in ways most people don’t realize. That system? The CYP enzymes, a family of liver proteins, mainly cytochrome P450, that break down over 70% of all prescription drugs. Also known as cytochrome P450 enzymes, they’re the reason some medications work faster, slower, or not at all when mixed with certain foods or supplements. Quercetin doesn’t just sit there—it can block or boost these enzymes, changing how your body handles drugs like blood thinners, statins, and even some antibiotics.

Think of CYP enzymes as traffic cops for your meds. If quercetin slows down CYP3A4, one of the most common enzymes, drugs like simvastatin or cyclosporine can build up in your system and cause side effects. On the flip side, if it speeds up CYP1A2, medications like caffeine or clozapine might get cleared too fast, making them less effective. This isn’t theory—it’s why people on warfarin or thyroid meds need to be careful with high-dose quercetin supplements. You won’t see it on the label, but studies show quercetin can alter drug levels by 20% to 40% in some cases. That’s enough to cause a fall, a bleed, or a seizure if you’re already on a tight dose.

What you’ll find in the posts below isn’t just a list of articles—it’s a practical map of how everyday supplements and medications collide. You’ll see how calcium and iron mess with thyroid drugs, how alcohol changes INR levels, and why generic pills look different but still work the same. These aren’t random topics. They’re all part of the same puzzle: how your body processes what you put in it. Whether you’re managing a chronic condition, taking multiple meds, or just wondering if that berry supplement is safe, this collection gives you real, no-fluff answers.