CBD and Warfarin: What You Need to Know About the Interaction
When you take CBD, a compound derived from the cannabis plant used for pain, anxiety, and sleep. Also known as cannabidiol, it's becoming a go-to for people looking for natural relief without the high. But if you're also on warfarin, a blood thinner prescribed to prevent clots in people with atrial fibrillation, deep vein thrombosis, or artificial heart valves. you’re playing with fire. These two don’t mix quietly. CBD slows down the liver enzyme CYP2C9, which is the same enzyme your body uses to break down warfarin. That means warfarin sticks around longer, and your blood gets thinner than intended. A study in the Journal of Clinical Medicine found that patients using both saw their INR levels jump by 30% or more within days — a red flag for internal bleeding.
It’s not just about one drug. CYP2C9, a key liver enzyme responsible for metabolizing many common medications, including warfarin and some NSAIDs. is the silent middleman here. If you’re taking other things that affect this enzyme — like certain antibiotics, antifungals, or even herbal supplements like feverfew — the risk piles up. You might not feel anything until it’s too late: unexplained bruising, nosebleeds that won’t stop, dark stools, or sudden headaches. These aren’t side effects you ignore. They’re warning signs your blood isn’t clotting like it should. And because CBD isn’t regulated like prescription drugs, the dose you get from a bottle or gummy can vary wildly. One day you take 10mg, the next day 25mg — and your INR swings with it.
There’s no safe dose of CBD if you’re on warfarin without medical supervision. Some doctors will tell you to avoid it entirely. Others might adjust your warfarin dose and monitor you closely with weekly blood tests. But the truth? Most people don’t even tell their doctor they’re using CBD. They think it’s harmless. It’s not. If you’re using both, you need a plan. Get your INR checked more often. Track every drop of CBD you take. And if you notice anything off — call your doctor before you call 911.
The posts below cover real cases and science-backed advice on how drugs and supplements interact. You’ll find guides on reading warning labels, spotting hidden risks with herbal products like feverfew, and understanding how your body processes medications. Whether you’re managing warfarin, considering CBD, or just trying to avoid a dangerous mix, these articles give you the facts — no fluff, no hype, just what you need to stay safe.
CBD Products and Prescription Medications: What You Need to Know About Dangerous Interactions
Dec, 7 2025