Ginkgo Biloba and Blood Thinners: What You Need to Know About Bleeding Risk

If you're taking blood thinners and thinking about trying Ginkgo Biloba for memory or circulation, stop. This isn't a harmless herb. It could put you in the hospital.

Why Ginkgo Biloba Is Riskier Than You Think

Ginkgo Biloba comes from the leaves of an ancient tree native to China. For decades, people have taken it hoping to improve memory, reduce dizziness, or boost blood flow. It’s sold everywhere - drugstores, health food shops, even online marketplaces. The standard dose? 120 to 240 mg per day. That’s what most studies use. But here’s the problem: Ginkgo doesn’t just affect your brain. It affects your blood.

Researchers have found that Ginkgo contains compounds that interfere with blood clotting. That sounds good if you’re trying to prevent clots - until you’re already on a blood thinner. Then it becomes dangerous. The American Society of Anesthesiologists says to stop Ginkgo 2 to 3 weeks before any surgery. Why? Because even minor cuts or internal bleeding can become life-threatening.

Case reports confirm this isn’t theoretical. One man developed spontaneous bleeding in his right eye after just one week of taking Ginkgo with low-dose aspirin. Another woman suffered a brain hemorrhage after years of daily Ginkgo - no other blood thinners involved. These aren’t rare accidents. They’re predictable outcomes.

Which Blood Thinners Are Most Dangerous to Mix With Ginkgo?

Not all blood thinners are the same. And not all combinations with Ginkgo carry the same risk. Some are far more dangerous than others.

Warfarin (Coumadin, Jantoven) is the biggest red flag. Studies show Ginkgo can raise your INR - a key test that measures how long your blood takes to clot. A higher INR means thinner blood. Too high, and you risk internal bleeding. There are documented cases of INR levels spiking into dangerous ranges after people started taking Ginkgo.

Clopidogrel (Plavix), an antiplatelet drug, also pairs dangerously with Ginkgo. Both stop platelets from clumping. Together, they can cause bleeding in the stomach, brain, or eyes. The same goes for aspirin - even the low 80 mg dose used for heart protection. Add Ginkgo, and your bleeding risk jumps by nearly 10% according to a 2023 PLOS ONE study.

Even common painkillers like ibuprofen (Advil, Motrin IB) and celecoxib (Celebrex) can become risky when mixed with Ginkgo. These drugs already irritate the stomach lining. Add Ginkgo’s anti-clotting effect, and ulcers or internal bleeding become more likely.

And it’s not just prescription meds. Over-the-counter supplements like garlic, ginger, and ginseng also thin the blood. Taking them with Ginkgo? You’re stacking the odds. One person taking all four had a major gastrointestinal bleed.

The Science Is Mixed - But That Doesn’t Mean It’s Safe

You might have heard that some studies say Ginkgo doesn’t affect blood clotting. That’s true - but misleading.

A 2023 PLOS ONE study tested a standardized Ginkgo extract called EGb 761 on 29 different blood clotting markers. None changed. Sounds reassuring, right? But here’s the catch: that study didn’t look at real-world bleeding events. It looked at lab tests. Real people bleed. And in other studies, when researchers tracked actual bleeding incidents - not just lab numbers - they found clear links.

Another study from the NIH found that while Ginkgo didn’t make people bleed more often, it did mess with coagulation test results. That means your doctor might see abnormal numbers and think you’re at higher risk - even if you’re not bleeding yet. It’s like a smoke alarm going off because someone burned toast. The alarm isn’t wrong. The toast just shouldn’t have been in there.

The truth? We don’t have perfect data. But we have enough warning signs to treat Ginkgo like a drug - because it acts like one.

Who Should Never Take Ginkgo Biloba?

Some people should avoid Ginkgo entirely - no exceptions.

• Anyone on blood thinners - warfarin, aspirin, Plavix, Xarelto, Eliquis, or anything else that prevents clots.
• People with bleeding disorders - hemophilia, von Willebrand disease, or even a history of frequent nosebleeds or easy bruising.
• Pregnant or breastfeeding women - Ginkgo may affect fetal circulation and isn’t proven safe.
• People over 65 - aging blood vessels are more fragile. Even small increases in bleeding risk can lead to serious outcomes.
• Anyone scheduled for surgery - dental work, knee replacement, even a colonoscopy. Stop Ginkgo at least two weeks before.

Mayo Clinic says it plainly: if you have a bleeding condition, skip Ginkgo. Period.

What About Other Interactions?

Ginkgo doesn’t just play with blood thinners. It messes with other meds too.

Antidepressants like fluoxetine (Prozac) and sertraline (Zoloft) may become less effective when taken with Ginkgo. That’s not just a theory - it’s been seen in clinical reports.

Statins like Lipitor and Zocor? Ginkgo might lower their effectiveness. That’s bad news if you’re taking them to protect your heart.

Diabetes meds - Ginkgo can lower blood sugar. If you’re on insulin or metformin, you could end up with dangerously low glucose levels.

Seizure medications - Ginkgo may reduce their effect. That’s a serious risk for anyone with epilepsy.

And don’t forget decongestants. Products with phenylephrine (like Sudafed PE) can raise blood pressure. Ginkgo may block the body’s ability to regulate that spike, leading to hypertensive crisis.

What Should You Do Instead?

If you’re considering Ginkgo for memory or circulation, ask yourself: is the risk worth it?

There’s no solid proof Ginkgo improves memory in healthy people. Some studies show tiny, short-term benefits in older adults with mild cognitive decline - but nothing dramatic. And the risks? They’re real.

Instead of Ginkgo, try proven alternatives:

• Exercise - even 30 minutes of walking daily improves blood flow and brain function.
• Omega-3s from fish oil - proven to support circulation without the bleeding risk.
• Mediterranean diet - rich in antioxidants, linked to better brain health.
• Control blood pressure and cholesterol - these matter far more than any supplement.

If you’re already taking Ginkgo, don’t quit cold turkey. Talk to your doctor or pharmacist. They can help you taper safely if needed.

How to Stay Safe

Here’s what you need to do right now:

1. Check every supplement you take - even if it says “natural” or “herbal.”
2. Bring a list of all your meds and supplements to every doctor’s visit.
3. Ask your pharmacist: “Could this interact with my blood thinners?”
4. If you’re having surgery, tell your surgeon and anesthesiologist about every herb, vitamin, or tea you take.
5. Stop Ginkgo at least two weeks before any procedure - don’t gamble with 36 hours.

The supplement industry isn’t tightly regulated. Two bottles of Ginkgo from different brands can have wildly different strengths - or even contaminants. The FDA doesn’t test them before they hit shelves. You’re the only one watching out for you.

Final Reality Check

Ginkgo Biloba isn’t a miracle cure. It’s a potent substance with real, documented risks. If you’re on blood thinners, the choice is simple: skip it. There’s no safe middle ground. No “low dose” that’s risk-free. No “I’ve been taking it for years and nothing happened.” That’s luck - not safety.

Over 1.5 million Americans take Ginkgo. Millions more worldwide. But no one ever wakes up thinking, “I hope I bleed today.” Yet every year, people do - because they didn’t know the risk.

Knowledge isn’t just power. In this case, it’s the difference between walking out of the hospital - and not walking out at all.