Herbs & Botanicals
What is ginkgo biloba? What is it used for?
Ginkgo is one of the oldest and adaptable species of trees in existence.
Ginkgo biloba trees existed before the Ice Age; some trees even
survived the atomic blast at Hiroshima in 1945.
A single ginkgo biloba tree can live as long as 1,000 years and
grow to a height of 120 feet. It has short branches with fan-shaped
lives and produces an inedible fruit (but an edible inner seed).
Ginkgo biloba extract (GBE) is produced from the tree's leaves.
It is one of the best researched herbal medicines on record, with
more than 400 published studies conducted on GBE. It is the most
frequently prescribed herbal medicine in Germany and France and
is rapidly becoming one of the most used herbal medicines in the
Ginkgo biloba extract increases circulation to the brain and the
extremities. It makes platelets less sticky, which helps prevent
embolisms and artherosclerosis. By increasing blood flow to the
brain, ginkgo biloba may prevent mental deterioration and dementia
in elderly patients; some small studies have shown that GBE may
slow (or even stop) the progression of Alzheimer's disease.
Because of its ability to improve circulation, GBE has been used
for a variety of vascular conditions, including Raynaud's syndrome,
impotence caused by impaired blood flow, and claudication in the
legs. There is some evidence that GBE may also reduce some symptoms
of PMS, including fluid retention, congestion and breast tenderness.
How much ginkgo biloba should I take?
Most practitioners recommend taking 120 milligrams daily, in two
or three divided doses of 50:1 extract standardized to 24% flavone
glycosides. For more serious cases of dementia of Alzheimer's,
up to 240 milligrams may be taken.
What forms of ginkgo biloba are available?
Dried ginkgo biloba is available in capsule form. GBE is also found
in tinctures and fluid extracts. Make sure that ginkgo biloba products
are standardiced to contain 24% flavone glycosides and 6% terpene
What can happen if I take too much ginkgo
biloba? Are there any interactions I should be aware of? What precautions
should I take?
When taken in recommended doses, ginkgo biloba is very safe; however,
there have been isolated cases of gastrointestinal disorders, headaches
and dizziness in patients taking excess amounts. Because it decreases
the effectiveness of platelet aggregation, it should not be taken
with blood-thinning agents such as coumadin or warfarin.
Because there is a lack of data concerning GBE's effects during
pregnancy, it should be used with caution by pregnant and lactating
women. Ginkgo biloba should not be given to children and infants.
As with all supplements, patients should consult with a health care
provider before taking ginkgo biloba.
- Bauer U. Six-month double-blind randomized clinical
trial of ginkgo biloba extract versus placebo in two parallel
groups of patients suffering from peripheral arterial insufficiency.
- Castelli D, Colin L, Camel E, et al. Pretreatment
of skin with a ginkgo biloba extract/sodium carboxymethyl-b-1,3-glucan
formulation appears to inhibit the elicitation of allergic contact
dermatitis in man. Contact Dermatitis 1998;38(3):123126.
- Chung KF, McCusker M, Page CP, et al. Effect
of a ginkgoloide mixture (BN52063) in antagonizing skin and platelet
responses to platelet-activating factor in man. Lancet 1987;1(1):248250.
- Le Bars PL, Katz MM, Berman N, Itil TM, Freedman
AM, Schatzberg AF. A placebo-controlled, double-blind, randomized
trial of an extract of ginkgo biloba for dementia. JAMA 1997;278:13271332.
- Ramassamy C, Christen Y, Clostre F, et al. The
ginkgo biloba extract, EGB761, increases synaptosomal uptake of
5-hydroxytryptamine in-vitro and ex-vivo studies. J Pharm Pharmacol 1992;44:943945.