Overview

Ginkgo, also called Ginkgo biloba, is one of the oldest living types of trees. Most ginkgo products use extract from ginkgo’s fan-shaped leaves.

Ginkgo has two main substances that are good for health. Ginkgo has flavonoids, which are antioxidants that help protect the body’s cells from damage. And it has a type of terpenoid. Terpenoids help keep blood moving by widening blood vessels.

Ginkgo most often comes as a tablet, extract, capsule, or tea taken by mouth. Don’t eat raw or roasted ginkgo seeds, which can poison you.

Much of the research on ginkgo focuses on its effect on dementia, memory, and pain caused by peripheral artery disease blocking blood flow to the arms and legs. The lack of blood flow is called claudication.

What the research says

Most research on the use of ginkgo for certain conditions shows that it helps little to none. More study is needed. Conditions include:

• Dementia. Some research shows that ginkgo may ease symptoms of dementia. But it doesn’t prevent or slow the progress of dementia.
• Claudication. Some small studies show that ginkgo may help people walk longer without pain. But large studies haven’t shown that ginkgo helps.

Some studies on ginkgo’s effect on memory suggest that ginkgo extract might improve memory slightly in healthy adults. But most studies show that ginkgo doesn’t improve memory, attention, or how the brain works.

Our take

Caution

Ginkgo seems to be safe to take for a short time. Research doesn’t support taking ginkgo to prevent or slow dementia or cognitive decline.

Safety and side effects

When taken by mouth in typical amounts, ginkgo seems to be safe for most healthy adults.

Ginkgo can cause:

• Headache.
• Low salt levels.
• Bleeding.
• Dizziness.
• The feeling of the heart pounding or racing, called palpitations.
• Upset stomach.
• Trouble passing stool, called constipation.
• Skin allergies.

Don’t eat raw or roasted ginkgo seeds. They can poison you.

For people who have epilepsy or any type of seizure, large amounts of ginkgo may raise the risk of seizures.

If you are older, have a bleeding condition, or are pregnant, don’t take ginkgo. The supplement might raise the risk of bleeding. If you’re having surgery, stop taking ginkgo two weeks before the surgery.

Ginkgo might get in the way of managing diabetes. If you take ginkgo and have diabetes, closely watch your blood sugar levels.

Some research has shown that giving rodents ginkgo raises their risk of getting liver and thyroid cancers.

Interactions

Ginkgo may react with many medicines. Check with your pharmacist before taking ginkgo with any medicine.

Possible interactions include:

• Alprazolam (Xanax). This medicine relieves symptoms of anxiety. Taking ginkgo with it might keep the medicine from working as well.
• Anticoagulants and antiplatelet drugs, herbs and supplements. These types of medicines, herbs and supplements lessen blood clotting. Taking ginkgo with them might raise the risk of bleeding.
• Anticonvulsants and seizure threshold-lowering medicines, herbs and supplements. Large amounts of ginkgo can cause seizures. Taking ginkgo could keep an anticonvulsant medicine from working as well.
• Antidepressants. Taking ginkgo with certain antidepressants, such as fluoxetine (Prozac), might keep them from working as well.
• Some statins. Taking ginkgo with simvastatin (Zocor, Flolipid) might keep the medicine from working as well. Ginkgo also appears to lower the effects of atorvastatin (Lipitor, Atorvaliq).
• Diabetes medicines. Ginkgo might change how people with diabetes respond to these medicines.
• Ibuprofen. Using ginkgo with ibuprofen (Advil, Motrin IB, others) may increase bleeding risk.