Does Ginkgo Cause Harm? Side Effects and Real Risks

For most people, ginkgo is well tolerated at the amounts commonly used in supplements and for limited periods. The side effects reported in clinical trials are generally mild and comparable to placebo, but there are specific situations in which ginkgo can cause harm: when it interacts with medicines (especially anticoagulants and antiplatelet drugs), when it is taken in excess, or in groups for which safety data are lacking, such as pregnant and breastfeeding women and children.

The short answer is therefore: it is not dangerous for everyone, but it is not harmless for everyone either. What decides is your health profile, the medicines you take and the dose. In the following sections we explain what the research shows about adverse effects, who should take extra care and which signs justify stopping and seeking help.

Does ginkgo have side effects? What the trials say

In clinical trials with standardised ginkgo extract (usually EGb 761), the frequency of adverse effects has been similar to placebo. In a meta-analysis of four randomised, placebo-controlled trials including 782 patients with mild dementia, the frequency of adverse events was equivalent between the group treated with 240 mg daily of EGb 761 and the placebo group ¹. In an earlier meta-analysis of nine trials, with 2,561 patients with cognitive impairment and dementia and durations of 22 to 26 weeks, adverse effects also did not raise a relevant safety signal ².

This does not mean that nobody feels anything. The effects most often reported in the literature are gastrointestinal discomfort, headaches, dizziness and palpitations. They are usually mild and transient. A review on the indications, mechanisms and safety of ginkgo also describes possible interactions with monoamine oxidase inhibitors, alprazolam, haloperidol, warfarin and nifedipine, and stresses that the optimal dose and duration, dose-response characteristics and long-term effects remain unclear ³.

If you feel any of these symptoms, the first thing to do is not to panic: stop taking it for a day or two and see whether the symptoms disappear. If they do, you can try starting again at a lower dose; if they persist, or if they are intense, speak to a pharmacist or doctor. Strong and persistent headaches deserve special attention — they are not dangerous in themselves, but they may be a sign that ginkgo is affecting your blood pressure or interacting with another medicine.

Who should speak to a healthcare professional before taking ginkgo

There are groups in which caution should come before curiosity. In all of them, the recommendation is the same: speak to your doctor or pharmacist before starting.

• People taking anticoagulants or antiplatelet drugs (for example, warfarin, aspirin or clopidogrel): ginkgo is among the natural products associated with interactions with warfarin, with an increased risk of bleeding ⁴.
• Pregnant and breastfeeding women: there are no clinical trials that allow safety to be established in these groups, so the decision should be made with a healthcare professional.
• Children and adolescents: there are not enough data to recommend ginkgo to anyone under 18; TuttiBear's gummies, for example, are intended for adults and should not be consumed by children.
• People due to have surgery: because of the potential effect on clotting, you should tell your doctor and the surgical team that you take ginkgo.
• People with a chronic disease or taking regular medication (diabetes, hypertension, epilepsy, psychiatric illness): individual assessment is essential.

There are also situations in which caution means avoiding it or speaking to a healthcare professional first: anyone with a bleeding disorder, such as haemophilia, or on dialysis should not take ginkgo without medical supervision, and the same applies to anyone with epilepsy, since there are reports that ginkgo may increase the risk of seizures. Anyone due to undergo surgery should tell their doctor and the surgical team that they take ginkgo — many professionals recommend stopping at least two weeks before any procedure, as a precaution.

If you are looking for information on what research has studied in this ingredient, it is worth reading our article on how ginkgo works and the ingredient page for ginkgo.

Interactions with medicines: where the most real risk lies

The most documented interaction is with anticoagulants and antiplatelet drugs. A systematic review on interactions between warfarin and foods, plants or supplements identified ginkgo among the products associated with an increased risk of bleeding, including cases of minor and major bleeding events ⁴. If you take any of these medicines, do not start ginkgo on your own initiative.

The safety review of ginkgo also mentions possible interactions with monoamine oxidase inhibitors, alprazolam, haloperidol and nifedipine ³. This does not mean that all these interactions are well characterised — it means that reports exist and that case-by-case assessment is necessary. The practical rule is simple: if you take regular medication, take the supplement pack to your pharmacist before adding it to your routine.

Ginkgo in people with specific diseases: what the studies show

A large part of the research on ginkgo has been carried out in populations with clinical conditions, and it is important not to extrapolate those results to healthy adults. Some examples:

• In patients with mild dementia, a meta-analysis of four trials with 782 participants showed that 240 mg daily of EGb 761 was superior to placebo in cognition, global assessment, activities of daily living and quality of life, with a frequency of adverse effects similar to placebo ¹.
• In patients with cognitive impairment and dementia, a meta-analysis of nine trials with 2,561 patients found benefits that, in the analysis, were mainly associated with 240 mg daily of EGb 761 ².
• In patients with unstable angina, a network meta-analysis assessed different ginkgo extract preparations as an add-on to conventional treatment ⁵.
• In patients with type 2 diabetes, a meta-analysis of 13 studies with 1,573 participants analysed haemorheological parameters, lipid profile and glycaemic control, without finding consistent differences in markers of glycaemic control or in lipid profile ⁶.

These studies do not say that ginkgo prevents or treats these diseases — they say only what was observed in those specific populations, often alongside conventional treatment. For a healthy adult looking for a supplement, the evidence is much less robust.

Ginkgo and bleeding: what is known and what is not

Ginkgo has antiplatelet effects attributed to flavanones and terpene lactones ³. In practice, this means it may increase clotting time, which is relevant above all for people already taking blood-thinning medicines. The review on interactions with warfarin includes ginkgo among the products to monitor, with reports of minor (purpura, gum bleeding) and major bleeding ⁴.

If you notice bruises that appear for no reason, frequent nosebleeds, blood in the stool or any unusual bleeding, stop taking it and seek medical advice. It is not a sign to panic, but it is a sign not to ignore.

Doses: what the studies used and what a label says

In clinical trials in dementia, the benefits observed were associated with 240 mg per day of standardised EGb 761 extract ^{2 1}. In other contexts, the doses studied ranged from 80 to 720 mg per day, over durations of two weeks to two years ³. These values are research doses, not instructions for taking.

For comparison, TuttiBear's Focus and Concentration Gummies provide 120 mg of ginkgo extract per serving of 2 gummies, in a jar of 60 gummies, with the direction to chew 2 gummies per day, preferably after a meal. The amount of ginkgo extract on the label is lower than the dose of EGb 761 used in the dementia trials — which is normal, because it is a food supplement and not a medicine, and because the extract in the supplement is not necessarily the same standardised extract studied. If you want to understand the differences between doses better, see the article on ginkgo daily dose.

Ginkgo gummies: format-specific precautions

Gummies are easy to take and pleasant to taste, but that brings its own precautions. The first is the risk of accidental overdose, especially in children: keep the jar out of reach of younger children. The second is the composition — the Focus and Concentration Gummies contain polyols (maltitol), and excessive consumption may have a laxative effect. The label also states that the product is intended for adults, should not be consumed by children, is not recommended for pregnant or breastfeeding women and that, in case of illness or when taking medicines, a healthcare professional should be consulted before consuming.

In case of accidental ingestion by a child, do not wait and see: contact your doctor, pharmacist or poison information centre. And remember that chewing a gummy leaves sugar or sweeteners in contact with the teeth, so good oral hygiene remains important.

If you are deciding between formats, we have a comparison in ginkgo gummies vs tablets. And if your question is about when to take it, see ginkgo: when to take it.

Common myths about ginkgo safety

"It's natural, so it's always safe." Not true. Ginkgo has real biological effects, including an antiplatelet effect, and that is precisely why it can interact with medicines ³.

"If it does nothing to me, I can take double." Increasing the dose does not necessarily increase the benefit and may increase the risk of adverse effects. The safety review stresses that dose-response and long-term effects remain poorly characterised ³.

"Ginkgo doesn't interact with anything." It does interact, at least with anticoagulants and antiplatelet drugs, and there are reports of interactions with other medicines ^{4 3}.

"Since it has been used for centuries, its safety is proven." Traditional use is a starting point, not proof of safety. Risk assessment is done with trials and pharmacovigilance, and that is where the information is still incomplete.

Warning signs: when to stop and seek help

Most side effects are mild and resolve when the dose is reduced or the supplement is stopped. But there are signs that justify immediate medical contact:

• Unusual bleeding: bruises without a cause, frequent nosebleeds, blood in the stool or urine.
• Allergic reaction: swelling of the face, lips or tongue, difficulty breathing, generalised skin rash.
• Neurological symptoms: seizures, loss of consciousness, sudden confusion.
• Cardiovascular: persistent palpitations, chest pain, severe dizziness.

If any of these signs occur, stop the ginkgo and seek help. Do not try to guess at home whether or not the symptom is related to the supplement.

So, does ginkgo cause harm or not?

For most healthy adults, with no relevant medication and no health conditions that increase risk, ginkgo is well tolerated at the doses commonly used in supplements. It causes harm mainly in three scenarios: when it interacts with medicines (in particular anticoagulants and antiplatelet drugs), when it is taken in excess or for a long time without reassessment, and in groups for which safety data are lacking, such as pregnant and breastfeeding women and children.

It is also worth adjusting expectations. The evidence for cognitive benefit is more consistent in populations with cognitive decline than in healthy adults, and even there the effects are modest ^{2 1}. If you are looking for an overview of what the research shows, see ginkgo benefits.

If you have any health condition, take regular medication, are pregnant or breastfeeding, or are thinking of giving ginkgo to a child, speak to a healthcare professional first. If you decide to try it, start with the dose on the label, observe how you feel and reassess periodically. Ginkgo is neither a poison nor a panacea — it is an ingredient with real effects that deserves to be used with information.

Frequently asked questions

Does ginkgo harm the liver?

There is no consistent evidence that ginkgo, at the doses commonly used in supplements, causes liver damage. Even so, if you have liver disease or take medicines metabolised by the liver, speak to your doctor before starting, because the assessment has to be individual.

Can I take ginkgo with anticoagulants?

You should not start ginkgo on your own initiative if you take anticoagulants or antiplatelet drugs, such as warfarin, aspirin or clopidogrel. Ginkgo has an antiplatelet effect and is associated with an increased risk of bleeding when combined with these medicines. Speak first to the doctor who prescribed your medication.

How long can I take ginkgo without a break?

There is no established maximum duration. In clinical trials, durations ranged from two weeks to two years, but those are research settings. In practice, it makes sense to reassess periodically with a healthcare professional whether you are taking it and whether it makes sense to continue.

Does ginkgo cause headaches?

Headaches are among the most frequently reported side effects, although in clinical trials the frequency of adverse effects was similar to placebo. If strong and persistent headaches occur, stop taking it and speak to a pharmacist or doctor.

Are ginkgo gummies safe for children?

There are not enough data to recommend ginkgo to anyone under 18, and TuttiBear's gummies are intended for adults and should not be consumed by children. Always keep the jar out of reach of younger children, because of the risk of accidental ingestion.

Can ginkgo be taken on an empty stomach?

The label of the Focus and Concentration Gummies recommends chewing 2 gummies per day, preferably after a meal. If you feel gastrointestinal discomfort, taking it after a meal may help. If in doubt, follow the label directions of the product you choose.