Ginkgo biloba is generally well tolerated, but it carries one serious risk that deserves real attention. Its main danger is bleeding, especially when combined with blood thinners, and roughly 3 to 5 complaints account for most reported issues.
Quick Answer
Most ginkgo biloba side effects are mild, including headache, nausea, and stomach upset in under 5% of users. The serious concern is bleeding, because ginkgo reduces platelet clumping and can add to blood thinners like warfarin or aspirin. Avoid it if you are pregnant, have a seizure disorder, or face surgery within 2 weeks.
Key Takeaways
- Mild side effects like headache or nausea affect under 5% of users
- Bleeding risk is the top concern, especially with 2 or more thinners
- Stop ginkgo 1 to 2 weeks before any planned surgery
- Avoid ginkgo with warfarin, aspirin, and the 3 main antiplatelet drugs
- People with seizure disorders should avoid ginkgo in all 3 forms
- Pregnant women and children under 18 should not take ginkgo
Common Ginkgo Biloba Side Effects
Most ginkgo biloba side effects are mild, short-lived, and affect only a small share of users. In trials the most common complaints were headache, nausea, dizziness, and stomach upset, each reported by under 5% of people and usually fading within the first 1 to 2 weeks of use.[1]Ginkgo Biloba Chemistry and Uses — PubMed View source
These mild effects are not the reason ginkgo needs caution. For context on the plant and its active compounds, see our guide to what ginkgo biloba is and how it works.
- Headache is the most frequently reported effect, usually mild and passing
- Nausea or stomach upset is reduced by taking ginkgo with food
- Dizziness affects a small minority, especially at higher doses
- Allergic skin reactions are uncommon but possible in sensitive people
Bleeding Risk: The Most Serious Concern
The most important ginkgo biloba safety issue is bleeding. Ginkgo blocks platelet-activating factor and reduces platelet clumping, so it can add to the effect of anticoagulant and antiplatelet drugs, and case reports link it to rare but serious spontaneous bleeding events.[2]Spontaneous Bleeding With Ginkgo Biloba — PubMed View source
Stop ginkgo 1 to 2 weeks before surgery or any dental procedure, and never combine it with prescription blood thinners unless your doctor has specifically approved it.
| Drug Class | Mechanism | What to Do |
|---|---|---|
| Warfarin | Adds to anticoagulation, may affect INR | Avoid unless your doctor approves and monitors |
| Aspirin and NSAIDs | Combined antiplatelet effect | Avoid or use only with medical guidance |
| Clopidogrel, antiplatelets | Additive bleeding risk | Avoid |
| SSRIs and SNRIs | Possible additive bleeding effect | Ask your doctor before combining |
Who Should Avoid Ginkgo Biloba
Certain groups should not take ginkgo biloba at all, regardless of dose. The 5 clearest cases involve bleeding risk, seizures, pregnancy, and upcoming procedures, where the potential harm outweighs any modest benefit the herb might offer.[3]Warfarin and Herbal Supplement Interactions — PubMed View source
If you are cleared to take it, choosing clean, filler-free ginkgo biloba capsules avoids unnecessary additives and keeps a single, standardized ingredient in your routine.
| Group | Why to Avoid |
|---|---|
| Pregnant or breastfeeding | Safety not established; bleeding risk in labor |
| Seizure disorders | May lower seizure threshold; raw seeds are worse |
| Before surgery (2 weeks) | Increases bleeding risk during and after procedures |
| On blood thinners | Additive effect with warfarin, aspirin, antiplatelets |
| Children under 18 | Not studied for safety or dosing in minors |
What Not to Mix With Ginkgo
Beyond prescription blood thinners, several supplements and medications deserve caution with ginkgo. The common thread is anything that also affects bleeding, blood sugar, or the nervous system, since the effects can stack in ways that are hard to predict.[4]Ginkgo Antiplatelet and Anticoagulant Interaction — PubMed View source
- Blood-thinning supplements such as fish oil, vitamin E, garlic, and turmeric at high doses
- Diabetes medications because ginkgo may influence blood sugar in some people
- Seizure medications since ginkgo may reduce their effectiveness
- SSRIs or MAOIs where combined effects on mood chemistry are not well studied
Ginkgo, Kidneys, Liver and Raw Seeds
Ginkgo biloba leaf extract is not known to damage the kidneys or liver in healthy adults at normal doses of 120 to 240 mg per day. The real toxicity concern is raw or roasted ginkgo seeds, which contain ginkgotoxin and can cause seizures if eaten in quantity.[5]Ginkgo — National Center for Complementary and Integrative Health View source
- Kidneys: no clear evidence of harm from standardized leaf extract in healthy people
- Liver: rare reports exist, so avoid if you have active liver disease
- Raw seeds: contain ginkgotoxin; eating many can trigger seizures, unlike leaf extract
Frequently Asked Questions
What are the most common side effects of ginkgo biloba? +
The most common side effects are headache, nausea, dizziness, and mild stomach upset, each reported by under 5% of users. They are usually mild and fade within the first 1 to 2 weeks. Taking ginkgo with food reduces nausea. The serious concern is not these mild effects but the risk of bleeding.
What medications should you not mix with ginkgo biloba? +
Avoid ginkgo with blood thinners: warfarin, aspirin, NSAIDs, and antiplatelet drugs like clopidogrel top the list. It may also interact with SSRIs, seizure medications, and diabetes drugs. Because ginkgo affects platelets, combining it with any of these 4 drug classes can raise bleeding or other risks. Always check with your doctor first.
What vitamins or supplements should not be mixed with ginkgo? +
Be cautious combining ginkgo with other blood-thinning supplements. The main 4 are fish oil, vitamin E, garlic, and high-dose turmeric, since together they can raise bleeding risk. This is especially important in the 2 weeks before surgery. Spacing or avoiding these combinations is safer than stacking several platelet-affecting supplements at once.
Does ginkgo biloba affect the kidneys? +
Standardized ginkgo leaf extract is not known to harm the kidneys in healthy adults at 120 to 240 mg per day. There is no strong evidence of kidney damage from normal use. However, if you have chronic kidney disease, talk to your doctor first, since supplement safety data in that group is limited.
Is ginkgo biloba bad for the liver? +
For most people, no. Standardized leaf extract shows no clear liver toxicity at 120 to 240 mg per day. There are only a handful of case reports of liver issues, and cause is hard to confirm. If you have active liver disease or take medications processed by the liver, check with your doctor before starting ginkgo.
Can ginkgo biloba cause headaches? +
Yes, headache is the single most commonly reported side effect, though it affects under 5% of users. It is usually mild and tends to ease within the first 1 to 2 weeks. Starting at a lower 120 mg dose and taking it with food can help. If headaches persist past 2 weeks, stop and reassess.
Does ginkgo biloba raise blood pressure? +
Ginkgo does not reliably raise blood pressure. A few small studies even showed slight reductions, but effects are inconsistent and too small to matter clinically. It is not a blood pressure treatment. If you take antihypertensive drugs, tell your doctor before adding ginkgo, mainly because it can also thin the blood at 240 mg daily.
Can you be allergic to ginkgo biloba? +
Yes, though allergic reactions are uncommon. People allergic to poison ivy or cashews may react to ginkgo, which shares related compounds called alkylphenols. Reactions range from mild skin rash to, rarely, more serious responses. If you notice a rash, itching, or swelling within 1 to 2 days of starting, stop and seek medical advice.
Are raw ginkgo seeds or nuts dangerous? +
Yes, raw and roasted ginkgo seeds are the real toxicity risk, unlike leaf extract. They contain ginkgotoxin, which can trigger seizures if you eat many, and cases have involved 10 or more seeds. Standardized leaf supplements do not contain meaningful ginkgotoxin. Never eat raw ginkgo seeds, and keep them away from children and pets.
Can ginkgo biloba cause bleeding? +
Yes, this is the most serious ginkgo concern. It reduces platelet clumping, and case reports link it to rare spontaneous bleeding, including a few brain bleeds. Risk rises sharply when combined with blood thinners. Stop ginkgo 1 to 2 weeks before surgery, and seek care for unusual bruising, nosebleeds, or bleeding gums.
Can ginkgo biloba interact with anesthesia or surgery? +
Yes, which is why you should stop ginkgo 1 to 2 weeks before any surgery or dental procedure. Its antiplatelet effect can increase bleeding during and after operations. Tell your surgeon and anesthesiologist about every supplement you take. Most surgical guidelines recommend pausing ginkgo and similar blood-thinning herbs at least 2 weeks ahead.
Related Reading
Related Products
