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Avoid in people with a known allergy or sensitivity to Ginkgo biloba, its parts, or members of the Ginkgoaceae family. There is possible cross-sensitivity in people allergic to urushiols (mango rind, sumac, poison ivy, poison oak, cashews).

Side Effects and Warnings

Ginkgo appears to be safe when taken by healthy adults by mouth in suggested doses for up to six months. The most concerning potential complication is bleeding, which has been life threatening in a small number of reports.

Ginkgo may cause higher or lower blood pressure. Caution is advised in people taking drugs or herbs and supplements that alter blood pressure.

Drowsiness or sedation may occur. Use caution if driving or operating heavy machinery.

Ginkgo may lower blood sugar levels. Caution is advised in people with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.

Use cautiously in people with a history of or at risk of stomach or intestine disorders, musculoskeletal disorders, nervous system disorders, psychiatric disorders, seizures, or skin disorders. Use cautiously in people at risk of Stevens-Johnson syndrome. Use cautiously in children, women trying to conceive, and pregnant or breastfeeding women.

Use cautiously in people taking agents for heart disease or seizures, anticholinergic agents, antidepressants, CYP450-metabolized agents, or St. John's wort. Use cautiously in people undergoing electroconvulsive therapy (ECT).

Ginkgo may increase the risk of bleeding. Avoid in people with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.

Avoid ingesting ginkgo seeds or pulp, due to potential adverse effects. Avoid 2-3 weeks prior to some surgical and dental procedures. Avoid in people with heart disease. Avoid ginkgo injected in the blood. Avoid consuming or handling with known allergy or hypersensitivity to Ginkgo biloba, its constituents, members of the Ginkgoaceae family, or urushiols (mango rind, sumac, poison ivy, poison oak, cashews), due to cross-reactivity potential.

Ginkgo may also cause altered insulin levels, anal sphincter spasms, behavioral changes, bleeding after surgery, bleeding of the eye, blood in urine, blurred vision, bruising, cardiac arrest, coma, constipation, death, diarrhea, distortion of taste, dizziness, dry mouth, edema, fertility reduction, gastrointestinal pain or irritation, headache, heart palpitations, hemorrhage, hypomania, increased appetite, increased bleeding, inflammation of the anus and rectum, internal bleeding in the skull or brain, irregular heartbeat, ischemia (reduced blood supply), loss of consciousness, mild gastrointestinal discomfort, mouth or lip inflammation, muscle tone loss, muscle weakness, nausea, negative interactions with St. John's Wort (muscle stiffness, rapid heartbeats, fever, restlessness, and sweating), nervousness, neurologic adverse affects, palpitations, priapism (prolonged erection), psychiatric adverse effects, rash, rectal burning, restlessness, sadness, sedation, seizures, serotonin syndrome via additive effects with MAOIs, skin reactions such as inflammation, numbness, rash or stinging, sleepiness, Stevens-Johnson syndrome, stroke, upset stomach, vomiting, weight loss, widened blood vessels, withdrawal syndrome and dependency.

Pregnancy and Breastfeeding

Ginkgo should be used with caution during pregnancy, due to the potential for increased bleeding risk. Ginkgo should be avoided during breastfeeding, due to a lack of sufficient data.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration