Ginkgo
Ginkgo
This information describes the common uses of Ginkgo, how it works, and its possible side effects.

Common Name

Fossil tree, Maidenhair tree; kew tree, Bai guo ye, Yinhsing

How It Works

Ginkgo does not improve memory or brain function, and does not prevent or decrease the occurrence of dementia or Alzheimer’s disease in elderly individuals.

Ginkgo biloba, one of the oldest living tree species, is used in traditional Chinese medicine and is also a popular supplement marketed to improve memory and circulation. Although some scientific studies have observed these properties, large clinical trials do not support the use of ginkgo to improve memory or prevent memory loss. In addition, one study suggests ginkgo supplementation may increase stroke risk, while other studies suggest it may have protective effects or did not see a significant increase in strokes. Therefore, more studies are needed to determine risks and any benefits with ginkgo supplementation.

Ginkgo inhibits platelet-activating factor, which is important for blood clotting, and therefore has blood-thinning qualities.

Purported Uses

  • To prevent memory loss or decline
    In several large studies among elderly patients, ginkgo did not improve memory. It also did not prevent Alzheimer’s disease or dementia, and did not prevent what is commonly known as “brain fog” among cancer patients.
  • To manage cardiovascular disease
    A large analysis did not find any benefit with ginkgo for heart disease.
  • To treat tinnitus
    Several studies indicate that ginkgo is not beneficial for tinnitus.

Do Not Take If

  • You have a blood clotting disorder.
  • You have a history of seizures.
  • You are at risk for stroke: Ginkgo may increase this risk.
  • You are taking warfarin or other blood thinners: Ginkgo may have additive effects, increasing the risk of spontaneous bleeding.
  • You are taking antipsychotic medications or prochlorperazine: Ginkgo may cause seizures when combined with these medications.
  • You are taking insulin: Ginkgo can alter insulin secretion and affect blood glucose levels.
  • You are taking trazodone: In one case, ginkgo extract was associated with coma in a woman with Alzheimer’s disease who was also taking trazodone. Use with caution and ask your doctor.
  • You are taking an antiretroviral such as efavirenz: Ginkgo may reduce its effectiveness.
  • You are taking nonsteroidal anti-inflammatory drugs (NSAIDs): Ginkgo can increase adverse effects.
  • You are taking amlodipine: Ginkgo may increase the risk of side effects of this drug.
  • You are taking a cytochrome P450 3A4 substrate drug: Ginkgo may increase the risk of side effects of these drugs.
  • You are taking a P-glycoprotein substrate drug: Ginkgo may increase the risk of side effects of these drugs.
  • You are taking a UGT substrate drug: Ginkgo may increase the risk of side effects of these drugs.

Side Effects

Case reports

Spontaneous bleeding: In a few cases, including in the eye and brain, related to ginkgo supplementation.

Prolonged bleeding: Among some healthy volunteers in a study that evaluated the interaction of gingko with antiplatelet drugs.

Seizures: In a few patients who were prone to seizures or on medications that lower the seizure threshold (e.g. prochlorperazine, chlorpromazine, perphenazine, etc.), ginkgo may have induced seizures.

Rash and itching: In a man after repeatedly ingesting a natural product containing ginkgo and vinpocetine.

Acute hemolytic anemia: In a patient after receiving an injection of G. biloba for dementia. Her symptoms resolved following intravenous fluid infusion and discontinuation of G. biloba.