I watched a TV series of ethnobotanist James Wong who investigates tree-based remedies for everyday ailments. He says Ginkgo tea is for memory. Just crush a few leaves and steep in hot water. http://christianhoughonline.com/blog/natural-remedies-by-james-wong/
when leaves sink to bottom, you can drink it.
Caution, if you are a Haemophiliacs, you should never take ginkgo, as its blood thinning properties are potentially very dangerous for people suffering from this condition. Similarly, individuals taking anti-coagulant medication should avoid ginkgo.
Ginkgo is an herb. The leaves are generally used to make “extracts” that are used as medicine. However, a few medicines are made from the seed, but these are not well studied.
Ginkgo is often used for memory disorders including Alzheimer’s disease. It is also used for conditions that seem to be due to reduced blood flow in the brain, especially in older people. These conditions include memory loss, headache, ringing in the ears, vertigo, difficulty concentrating, mood disturbances, and hearing disorders. Some people use it for other problems related to poor blood flow in the body, including leg pain when walking (claudication), and Raynaud’s syndrome (a painful response to cold, especially in the fingers and toes).
Ginkgo leaf is also used for thinking disorders related to Lyme disease and depression.