Ginkgo Biloba Side Effects | Safety & What to Know

Ginkgo Biloba is one of the oldest living tree species on earth, traceable back more than 200 million years. Its leaves have been used in traditional Chinese medicine for millennia, and modern standardized extracts — concentrated to provide optimal levels of naturally occurring flavonglycosides and terpene lactones — are among the most widely studied herbal supplements in the world. Ginkgo Biloba is commonly used to support memory, circulation, focus, and concentration.

While Ginkgo Biloba is generally considered safe and well-tolerated, understanding Ginkgo Biloba side effects is essential for anyone considering this supplement. Systematic review data show that overall adverse events and serious adverse events with standardized Ginkgo Biloba extract were at the same level as placebo, with fewer adverse events observed in the subgroup of Alzheimer's disease patients and fewer incidences of vertigo, tinnitus, angina pectoris, and headache compared to placebo.

Even so, certain populations and medication combinations warrant extra caution. This guide covers the known side effects, safety considerations, and drug interactions drawn from the scientific literature so you can make an informed decision.

Research suggests that Ginkgo Biloba side effects are typically mild when they do occur. The most commonly reported mild adverse effects include gastrointestinal upset, headaches, and dizziness.

One factor that can influence side effects is ginkgolic acid content. Ginkgolic acids are structurally similar to the irritants in poison ivy and are responsible for some toxic effects of lower-quality ginkgo preparations, including gastrointestinal disturbances, headaches, skin irritation, dermatitis, and edema. This is why standardization matters: the pharmaceutical-grade extract EGb 761, for example, contains less than 5 parts per million (ppm) of ginkgolic acids, significantly reducing this risk.

Choosing a Ginkgo Biloba product that has been standardized under strict quality guidelines — comparable to over-the-counter drug standards — helps ensure that ginkgolic acid levels are minimized and that you receive consistent, safe levels of the beneficial active compounds.

The interaction between Ginkgo Biloba and anticoagulant or antiplatelet drugs is one of the most clinically discussed Ginkgo Biloba side effects. The evidence is notably mixed. Initial concerns were based on case reports describing a temporal association between ginkgo use and bleeding events, though some evaluations of randomized controlled trials have not found a higher bleeding risk.

A systematic review and meta-analysis of 18 randomized controlled trials found a significant reduction in blood viscosity with ginkgo use; however, there were no effects on ADP-induced platelet aggregation, fibrinogen concentration, activated partial thromboplastin time, or prothrombin time.

Nonetheless, institutional bodies flag this interaction. The NCCIH notes that taking Ginkgo Biloba with warfarin is associated with increased risk for major bleeding events compared to warfarin alone. A large hospital-based observational study found that Ginkgo Biloba extract frequently interacts with antiplatelets, anticoagulants, and nonsteroidal anti-inflammatory drugs, with significant correlations between ginkgo drug interactions and bleeding risk (OR: 1.08, p < 0.001) and abnormal coagulation (OR: 1.49, p < 0.001).

Ginkgo may also increase the risk of bleeding in people taking anticoagulant drugs such as warfarin. Additionally, concomitant use of Ginkgo Biloba preparations and efavirenz (a non-nucleoside reverse transcriptase inhibitor) is not recommended, as ginkgo's induction of cytochrome P450 enzymes — particularly CYP3A4 — can reduce plasma concentrations of co-administered drugs that rely on this metabolic pathway.

Ginkgo Seeds vs. Leaf Extract: A Critical Distinction

It is important to distinguish between ginkgo leaf extract supplements and ginkgo seeds. Fresh ginkgo seeds are toxic when consumed orally, and serious side effects — including seizures and death — have occurred in people who consumed raw ginkgo seeds or the crude ginkgo plant. Roasted ginkgo seeds can also cause adverse reactions. The neurotoxic compound in ginkgo seeds primarily responsible for seizures is ginkgotoxin (4-O-methylpyridoxine), which acts as an antagonist of vitamin B6 and can precipitate seizures, particularly in children and with large quantities. This is a distinct hazard from standardized ginkgo leaf extract supplements.

Pregnancy

Ginkgo may be unsafe for use during pregnancy. It might cause early labor or extra bleeding during delivery if used near that time. Little is known about whether it's safe to use ginkgo while breastfeeding.

While Ginkgo Biloba is generally safe for most adults, certain groups should exercise particular caution regarding Ginkgo Biloba side effects:

• People taking anticoagulant or antiplatelet medications — including warfarin, clopidogrel, aspirin, or nonsteroidal anti-inflammatory drugs — should consult their healthcare provider before using ginkgo, due to the potential for increased bleeding risk.
• People taking efavirenz or other medications metabolized by CYP3A4 enzymes should avoid concurrent ginkgo use, as it may reduce the effectiveness of these medications.
• Pregnant or breastfeeding women should avoid Ginkgo Biloba, as it may cause early labor or extra bleeding during delivery.
• Anyone scheduled for surgery should inform their healthcare provider about ginkgo use, given its potential effects on blood viscosity and platelet function.

For the general population seeking to support memory, circulation, and focus, research suggests that standardized Ginkgo Biloba leaf extract has an acceptable safety profile, with most reported adverse reactions constituting rare occurrences.

Take one (1) vegetarian capsule, two (2) times daily with meals.

This product is gluten free, dairy free, soy free, and grain free. To minimize potential Ginkgo Biloba side effects, always take ginkgo with food as directed. If you are taking any medications — particularly anticoagulants, antiplatelet drugs, or medications metabolized by CYP3A4 — consult your healthcare provider before beginning supplementation.