Gingko biloba, often referred to as simply gingko, is an herbal extract prepared from the leaves of the gingko biloba tree. Many people take gingko supplements to treat a wide range of diseases, including dementia and cardiovascular disease. Gingko is usually safe, and no maximum dose as been established by health authorities. However, the risk of side effects may increase with larger doses. As with any health supplement, ask your doctor before taking gingko.
General Side Effects
Gingko supplements may cause side effects, most of which are mild. Commonly reported side effects include nausea, upset stomach and diarrhea, reports the National Center for Complementary and Alternative Medicine. Constipation, dizziness and headache are also possible. In certain people, gingko may cause a sensation of a pounding or forceful heartbeat.
Severe Bleeding
Another possible side effect of gingko supplements is thinning of the blood, which may increase the risk of excess bleeding. Cases of bleeding in the eye and in the brain have been linked to gingko, according to MedlinePlus. The risk of severe bleeding may increase if other blood-thinning medications, such as cilostazol, are taken at the same time. However, warfarin, another common blood thinner, does not appear to interact with gingko to increase the risk of bleeding, the University of Maryland explains. If you are taking blood-thinners, ask your doctor before taking gingko.
Allergic Reaction
In certain individuals, ginkgo may cause an allergic reaction. People who are allergic to poison oak, poison ivy, poison sumac, cashew shells and mango rind are more likely to be allergic to gingko, reports MedlinePlus. Raw gingko fruit and pulp is likely to cause allergic reactions when placed directly on the skin. Symptoms of an allergic reaction include itching, rash and swelling. In rare cases, a severe allergic reaction can lead to swelling of the airways, resulting in difficulty breathing.
Gingko Seeds
Raw or roasted gingko seeds contain high levels of a toxin called ginkgotoxin. Eating the whole seeds can result in severe adverse reactions, including weak pulse, seizures, difficulty breathing, unconsciousness and possibly death, warns the National Center for Complementary and Alternative Medicine. The raw seeds are more dangerous than roasted seeds. The gingko extracts used to make health supplements are typically made from the leaves, not the seeds of the tree, and contain very little gingkotoxin.
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