Ginkgo Biloba and Blood Thinners: What You Need to Know Before Taking Both

Millions of people take Ginkgo Biloba every day - not because it’s trendy, but because they believe it helps their memory, focus, or circulation. It’s one of the most popular herbal supplements in the U.S. and Europe. But here’s the problem: if you’re also on a blood thinner, you might be putting yourself at risk without even knowing it.

What Exactly Is Ginkgo Biloba?

Ginkgo Biloba comes from the leaves of the Ginkgo tree - one of the oldest living tree species on Earth, unchanged for over 270 million years. The extract used in supplements is standardized, meaning it’s processed to contain consistent levels of active compounds: 24% flavonol glycosides and 6% terpene lactones. This specific formula, known as EGb 761, is what most clinical studies use and what you’ll find in reputable brands.

It’s been used in traditional Chinese medicine for centuries, but only became widely available in the West in the 1980s. Today, it’s sold as capsules, tablets, teas, and liquid extracts. People take it for brain health, tinnitus, and poor circulation. But none of those benefits matter if it’s interacting dangerously with your medication.

How Ginkgo Biloba Might Affect Blood Thinners

Blood thinners - whether they’re aspirin, warfarin, clopidogrel, or newer drugs like apixaban - work by stopping your blood from clotting too easily. That’s critical for people with atrial fibrillation, history of stroke, or after stent placement. But Ginkgo Biloba doesn’t just sit quietly in your system. It has properties that can interfere with how your blood clots.

Research shows Ginkgo may reduce platelet aggregation - meaning it makes your platelets less likely to stick together and form clots. That sounds helpful, right? But if you’re already on a blood thinner, that’s like adding another layer of protection your body doesn’t need. It’s stacking effects.

Some lab studies suggest Ginkgo might also affect the liver enzyme CYP2C9, which breaks down warfarin. If that enzyme slows down, warfarin builds up in your blood, increasing your risk of bleeding. That’s not just a theory - it’s been seen in real cases. The FDA has logged 18 reports of bleeding events linked to Ginkgo use between 2008 and 2020. No one proved Ginkgo caused them directly, but in every case, the person was also taking blood thinners.

What the Experts Say - And Why They Disagree

Here’s where it gets messy. Some top medical sources say Ginkgo is safe with blood thinners. A 2008 review in PubMed concluded that well-designed studies showed no significant interaction. They pointed out that most bleeding cases involved low-quality, non-standardized Ginkgo products - the kind you might buy from a street vendor or unregulated online store.

But other equally respected sources say the opposite. The Mayo Clinic, Cleveland Clinic, and GoodRx all warn against combining Ginkgo with blood thinners. They list warfarin as a "high-risk" interaction and aspirin or clopidogrel as "moderate-risk." The American Society of Health-System Pharmacists calls the risk "theoretical," but still advises caution.

Why the gap? Because science doesn’t always give clear answers. Controlled trials often use pure, standardized extracts like EGb 761. Real-world users? They’re taking whatever’s on the shelf - different doses, different brands, sometimes mixed with other herbs like garlic or ginseng, which also affect bleeding.

Which Blood Thinners Are Most Concerning?

Not all blood thinners are the same. Here’s how Ginkgo interacts with the most common ones:

• Warfarin (Coumadin, Jantoven): Highest concern. Ginkgo may slow its breakdown, leading to dangerously high levels in your blood. Case reports show increased INR levels and serious bleeding.
• Aspirin: Both reduce platelet function. Together, they may increase bruising or nosebleeds. Not life-threatening for most, but risky if you’re prone to bleeding.
• Clopidogrel (Plavix): Used after heart attacks or stents. Ginkgo may amplify its antiplatelet effect. A 2020 study found 2.6% of clopidogrel prescriptions were taken with Ginkgo - a risky combo.
• DOACs (Apixaban, Rivaroxaban, Dabigatran): Newer drugs with fewer interactions, but still not risk-free. A 2020 study found 18% of DOAC users taking Ginkgo - and 48.7% of those were at high risk of interaction.

The bottom line? If you’re on any of these, Ginkgo isn’t worth the gamble.

What About Surgery or Dental Work?

This is where the stakes get highest. If you’re scheduled for surgery - even a simple tooth extraction - your surgeon or dentist needs to know if you’re taking Ginkgo. Bleeding during or after the procedure can be serious, even deadly.

Most experts agree: stop Ginkgo before any procedure. But how long?

• The American Society of Anesthesiologists recommends stopping 36 hours before surgery.
• Dr. Michael Murray and others suggest 36-48 hours.
• Dr. Tieraona Low Dog and some integrative medicine centers recommend 2 weeks - just to be safe.

Why the range? Because Ginkgo’s effects on platelets can linger longer than its presence in your bloodstream. If you’re having major surgery, err on the side of caution. Tell your doctor. Write it down. Don’t assume they’ll ask.

What Other Supplements Can Make This Worse?

Ginkgo doesn’t work alone. Many people take multiple supplements thinking they’re harmless. But combining Ginkgo with other blood-thinning herbs multiplies the risk.

Watch out for:

• Garlic - even raw cloves or supplements can thin blood.
• Danshen - a Chinese herb used for heart health, known to interact with warfarin.
• Evening primrose oil - may increase bleeding time.
• Fish oil - high doses (over 3,000 mg EPA/DHA daily) can affect clotting.
• Curcumin (turmeric) - has antiplatelet effects.

If you’re on a blood thinner, avoid stacking these. One might be okay. Two or three? That’s a recipe for trouble.

What Should You Do?

Here’s the practical advice - no fluff, no guesswork:

1. Don’t start Ginkgo if you’re already on a blood thinner. Period.
2. If you’re already taking it, talk to your doctor or pharmacist before stopping. Abruptly quitting isn’t always safe either.
3. Always disclose every supplement you take - even if you think it’s "just herbal."
4. Ask your pharmacist to run a full interaction check. Most pharmacies do this for free.
5. Read labels. If your Ginkgo bottle doesn’t warn about blood thinners, consider switching brands. 42% of manufacturers now include this warning - the others haven’t caught up.
6. Before any medical procedure, stop Ginkgo at least 36 hours ahead. For major surgery, go with 2 weeks.

What If You’ve Already Had a Bleeding Episode?

If you’ve had unexplained bruising, nosebleeds, blood in your urine or stool, or a headache that won’t quit - and you’re taking Ginkgo and a blood thinner - stop the supplement immediately. Call your doctor. Get your INR checked if you’re on warfarin. Don’t wait.

One case report from 2019 described a 72-year-old woman on warfarin who developed a brain hemorrhage after taking Ginkgo for 6 months. She had no other risk factors. She survived - but barely. Her doctors called it "a textbook example of a preventable interaction."

That could be you. Or your parent. Or your neighbor.

Bottom Line

There’s no perfect answer. Science hasn’t proven Ginkgo always causes bleeding with blood thinners. But it’s shown enough red flags to warrant extreme caution. The risks aren’t theoretical - they’re documented in real people. And the consequences? They can be fatal.

Herbal doesn’t mean safe. Natural doesn’t mean harmless. If you’re on a blood thinner, Ginkgo Biloba isn’t worth the risk. There are safer ways to support brain health - exercise, sleep, omega-3s, and managing blood pressure. Skip the supplement. Talk to your doctor. Protect your health - not just your memory, but your life.

What to Do Next

Don’t wait for a bleeding event to happen. If you’re taking Ginkgo and a blood thinner, schedule a quick appointment with your pharmacist or doctor. Bring your supplement bottles. Ask: "Is this safe with what I’m on?" Most will check for free.

And if you’re thinking of starting Ginkgo for memory or circulation - pause. Ask yourself: Is this worth the risk? There are proven, safer ways to support brain health. You don’t need a supplement to do it.