Q&A : ADVICE FROM EXPERTS SOME TOUT GINKGO LEAVES AS FOUNTAIN OF YOUTH.

If you haven't heard about the healthful benefits of ginkgo biloba leaves recently, where have you been? The pharmaceutical industry is touting the leaves as a virtual fountain of youth, able to tackle a myriad of ailments from memory loss to depression. Ginkgo biloba is available in many forms without a prescription. Physicians are recommending it.

Bessie Smith, a fourth-generation herbalist who works at Capitol Drugs in West Hollywood; and Parris Kidd, a nutrition educator and biomedical consultant based in Albany, Calif., provided the following information.

What is ginkgo?

It's a dietary supplement extracted from ginkgo biloba tree leaves. The trees are common in Asian countries, including China and Japan. The Chinese like to eat ginkgo nuts and pulverize them into a porridge. Private companies now are cultivating their own ginkgo trees in the United States.

How does ginkgo work?

It affects the body, after digestion, in two primary ways. First, its chemical makeup speeds blood circulation through the body so it gets more oxygen to function at its peak. Second, ginkgo is an anti-oxidant, so it slows the progress of disease and aging.

What are ginkgo's other purported benefits?

It can improve alertness, fight vertigo and depression, and stave off hearing loss. It's particularly effective for people who have poor circulation. But, ginkgo doesn't work in isolation. A healthy lifestyle that includes no alcohol or smoking is crucial.

Are there any side effects?

Yes. There can be occasional dizziness, headaches and upset stomachs.

How much does it cost?

When visiting a pharmacy, expect to pay between $14 and $25 for roughly 45 to 100 tablets. Ginkgo biloba also is available as tea, soft gels and ground-up powder in health-food stores. Labels recommend taking several tablets daily and/or consulting your physician for an appropriate dosage.