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

Many people take Ginkgo Biloba to support memory, focus, or circulation. It’s one of the most popular herbal supplements in the U.S., with millions using it every year. But if you’re also on a blood thinner-whether it’s warfarin, aspirin, clopidogrel, or a newer drug like apixaban-you need to pause and ask: is this safe?

Why Ginkgo Biloba Raises Concerns

Ginkgo Biloba comes from the leaves of a tree that’s been around for over 270 million years. It’s been used in traditional Chinese medicine for centuries, but modern extracts like EGb 761 are standardized and sold globally. The most common form contains 24% flavonol glycosides and 6% terpene lactones-these are the compounds believed to affect blood flow.

The issue isn’t that Ginkgo makes your blood thick. It’s the opposite. Some research suggests it may interfere with platelet function, which are the cells in your blood that help clots form. If you’re already on a medication that thins your blood, adding something that might reduce clotting even further could increase your risk of bleeding.

The Evidence Is Mixed

Here’s where it gets confusing. Some studies say Ginkgo is fine. Others say it’s dangerous.

A 2008 review of clinical trials found no significant increase in bleeding when Ginkgo was taken with aspirin or warfarin. These were controlled studies using high-quality, standardized extracts. But then there are case reports-real people who had serious bleeding events after taking Ginkgo with blood thinners. One man had a brain bleed after combining Ginkgo with warfarin. Another had uncontrolled bleeding after surgery because he didn’t stop taking Ginkgo beforehand.

The key difference? The bad outcomes usually involved non-standardized supplements. That means the product didn’t have consistent levels of active ingredients. Some brands might have too much, some too little, and some might even be contaminated. That’s why experts say the problem isn’t Ginkgo itself-it’s the lack of quality control in the supplement market.

Which Blood Thinners Are Most Risky?

Not all blood thinners are the same. And not all interact with Ginkgo the same way.

• Warfarin (Coumadin): This is the big one. Ginkgo may interfere with how your body breaks down warfarin through the CYP2C9 enzyme. Even small changes can make your INR levels climb, increasing bleeding risk. The Mayo Clinic and GoodRx both list this as a high-risk interaction.
• Aspirin: Studies show mixed results. Some found no effect. Others saw a slight increase in bleeding time. The risk is lower than with warfarin, but still present.
• Clopidogrel (Plavix): This antiplatelet drug works similarly to how Ginkgo might. Combining them could theoretically reduce your blood’s ability to clot. The PLOS ONE study found a 2.6% interaction rate in prescriptions.
• DOACs (apixaban, rivaroxaban, dabigatran): These newer drugs don’t rely on the same liver enzymes as warfarin, so the interaction is less likely. But there’s still not enough data. Case reports exist. So caution is advised.

What Do Experts Actually Recommend?

There’s no universal rule. But here’s what major institutions say:

• Mayo Clinic: Says Ginkgo may raise bleeding risk with aspirin, clopidogrel, or warfarin. Advises talking to your doctor.
• Cleveland Clinic: Lists blood thinners as a direct contraindication-meaning don’t take Ginkgo if you’re on one.
• American Society of Anesthesiologists: Recommends stopping Ginkgo at least two weeks before any surgery.
• GoodRx (2024): Says avoid Ginkgo entirely with warfarin. Use caution with others.
• American College of Chest Physicians: Says routine discontinuation isn’t needed because evidence is weak.

So why the contradiction? Because some rely on case reports (real-world events), while others rely on clinical trials (controlled settings). The truth? Both matter. If you’re healthy and taking low-dose aspirin, the risk might be minimal. But if you’re elderly, on multiple blood thinners, or have a history of bleeding, the stakes are much higher.

What Should You Do?

Don’t guess. Don’t assume it’s safe because it’s "natural." Here’s what to do:

1. Check your meds. Make a list of everything you take-prescriptions, supplements, even over-the-counter pain relievers like ibuprofen. Many people don’t realize NSAIDs also increase bleeding risk.
2. Talk to your pharmacist. They see drug interactions every day. Ask: "Is Ginkgo safe with my current blood thinner?"
3. Be honest with your doctor. If you’re already taking Ginkgo, don’t hide it. Many patients don’t mention supplements because they think it’s "not medicine." But it can affect your treatment.
4. Stop before surgery. Whether it’s a dental extraction or heart surgery, stop Ginkgo at least 2 weeks before. That’s the safest window.
5. Choose quality. If you do take it, pick brands that say "EGb 761" on the label. That’s the standardized extract used in most clinical studies.

What About Other Supplements?

Ginkgo isn’t alone. Several other herbs and supplements can also thin your blood:

• Garlic (especially raw or in high doses)
• Danshen (Chinese herb used for heart health)
• Evening primrose oil
• Fish oil (in doses over 3,000 mg/day)
• Green tea extract (in concentrated forms)

If you’re on a blood thinner, treat all of these the same way: talk to your doctor before taking them. Just because something is sold as a "natural remedy" doesn’t mean it’s harmless.

The Bottom Line

Ginkgo Biloba isn’t inherently dangerous. But when paired with blood thinners, the risk isn’t theoretical-it’s real enough that hospitals now have electronic alerts for this combo. The FDA has received dozens of reports of possible bleeding events linked to Ginkgo over the last 15 years. While causality isn’t proven in every case, the pattern is clear enough to warrant caution.

If you’re considering Ginkgo for memory or circulation, ask yourself: is the benefit worth the risk? For most people on blood thinners, the answer is no. There are safer ways to support brain health-exercise, sleep, managing blood pressure, and eating a balanced diet. You don’t need a supplement to do that.

And if you’re already taking Ginkgo? Don’t quit cold turkey. Talk to your doctor. They can help you decide whether to stop, switch, or keep going-with eyes wide open.