What is Ginkgo?
Ginkgo is one of the oldest living tree species. The extract of ginkgo leaves is used medicinally in North America, where it's one of the most popular medicinal herbs, and many other countries around the world. In traditional Chinese medicine, the seeds of the ginkgo tree are used.
Other names for ginkgo include Maidenhair tree, Kew tree, and Japanese silver apricot.
Why Do People Use Ginkgo?
- To improve memory
- Alzheimer's disease
- Peripheral artery disease
- Macular degeneration
- Alzheimer's disease
- Sexual dysfunction
- To enhance blood circulation
Ginkgo leaves are believed to contain compounds that thin blood and help to improve muscle tone in the walls of blood vessels. This may enhance blood flow.
What are the Safety Concerns?
Constituents in ginkgo leaves may affect blood clotting, so ginkgo leaf extracts shouldn't be used by people with bleeding disorders. People with epilepsy (or anyone with a history of seizures) should avoid ginkgo, because it may increase the frequency of seizures.
Ginkgo leaf products may affect blood sugar levels, so people with diabetes should only be used under the supervision of a health care provider.
The safety of ginkgo in pregnant or nursing women and children isn't known.
What are the Side Effects of Ginkgo?
Side effects of ginkgo leaf include excessive bleeding. Rarely, seizures have been reported in people using either the ginkgo leaf or seed. Other side effects include digestive problems, headaches, allergic skin reactions, or muscle weakness.
People should not consume fresh ginkgo seeds. Roasted ginkgo seeds may cause diarrhea, nausea, indigestion, vomiting, or allergic skin reactions. Side effects of fresh ginkgo seeds or over 10 roasted ginkgo seeds may include difficulty breathing, seizures, unconsciousness and death.
Possible Drug Interactions
Ginkgo can increase the effect of blood-thinners (antiplatelet or anti-clotting drugs), such as clopidogrel, ticlopidine (Ticlid), warfarin (Coumadin), heparin, and aspirin, which may result in uncontrolled bleeding or hemorrhage. Certain herbs, such as danshen, devil's claw, eleuthero, garlic, ginger, horse chestnut, papain, red clover, and saw palmetto, can also increase the risk of bleeding if combined with ginkgo.
Ginkgo has been found to interfere with the metabolism of drugs processed by an enzyme called cyp3A4. Ask your doctor to check if you are taking medications of this type.
Ginkgo may increase the risk of seizures if combined with other drugs or herbs that do the same, such as antidepressants, bupropion (Wellbutrin, Zyban), certain antibiotics such as penicillin and cephalosporins, Corticosteroids, fentanyl (Actiq, Duragesic), theophylline, methylphenidate (e.g. Concerta, Ritalin), drugs that suppress the immune system, such as azathioprine and cyclosporine, borage, evening primrose, and wormwood.
Ginkgo shouldn't be used with the drug cyclosporine (used to suppress the immune system), because it has been found to decrease the effect of that drug. Theoretically, ginkgo may have the same effect with other immunosuppressant drugs.
Ginkgo may interact with insulin and other drugs for diabetes, such as metformin (Glucophage), glyburide (Glynase), glimepiride (Amaryl), and glipizide (Glucotrol XL). It shouldn't be used with medications to prevent seizures.
There have been some cases of high blood pressure in people taking ginkgo and thiazide diuretics, such as chlorothiazide, chlorthalidone, hydrochlorothiazide, metolazone, and polythiazide.