When you're on warfarin, a blood thinner used to prevent dangerous clots, even small changes in your diet or supplements can have big consequences. Dong Quai, a traditional Chinese herb often used for menstrual and menopausal symptoms is one of those changes that can slip under the radar—but it’s not harmless. This herb has natural blood-thinning properties that can amplify warfarin’s effect, pushing your INR levels into dangerous territory. Many people assume herbal means safe, but that’s not true when it comes to blood thinners. The combination can lead to uncontrolled bleeding, even from minor cuts or bruises.
What makes this interaction especially tricky is that you won’t always feel it coming. Unlike some drug interactions that cause nausea or dizziness, Dong Quai and warfarin work silently in your bloodstream. Your INR—the test that measures how long it takes your blood to clot—can spike without warning. A normal INR for someone on warfarin is usually between 2 and 3. If it climbs above 4, your risk of internal bleeding, brain hemorrhage, or life-threatening bruising goes up sharply. Studies have shown cases where people taking Dong Quai alongside warfarin needed emergency treatment just because they didn’t realize the herb was affecting their meds. Other herbs like ginseng, garlic, and ginger can also interfere, but Dong Quai is one of the most potent and commonly used ones. If you’re on warfarin, you need to treat herbal supplements like prescription drugs: ask your doctor before starting, stopping, or changing anything.
It’s not just about avoiding Dong Quai—it’s about knowing what else might be hiding in your supplements. Some multivitamins, women’s health blends, or "blood-cleansing" formulas contain Dong Quai without clearly listing it. Always check the ingredient list. And if you’ve been taking it for years without issues, don’t assume it’s safe now. Your body changes. Your warfarin dose might change. Your liver function might shift. All of that affects how the two interact. If you’ve ever noticed unusual bruising, nosebleeds that won’t stop, dark stools, or sudden headaches while taking Dong Quai and warfarin together, that’s not normal. It’s a red flag. Call your doctor or go to urgent care. Your safety isn’t about avoiding herbs altogether—it’s about being informed, tested, and in control. Below, you’ll find real cases and clear guidance on how to navigate these risks without guessing.
Dong Quai and warfarin can dangerously increase bleeding risk when taken together. Learn why this herbal supplement is not safe for people on blood thinners, what the evidence shows, and what to do instead.
