There is little reason to use unprocessed ginkgo leaf in healthcare. There is no medicinal tradition for it and almost all modern research has been based on a highly refined and very concentrated proprietary extract patented in the 1960s and official only in one national pharmacopoeia. The extract and leaf are so different that it is unsafe to assume the leaf has any effect, unless it is assured to have comparable constituents by manufacturing process. Ginkgo biloba itself is described as a 150 million year old living fossil, planted around temples in China for centuries. In the 1960’s German scientists, pursuing their search for new remedies that might affect the circulation (a key healthcare focus in that country), found that the leaves of Ginkgo were particularly active in the laboratory. A special, highly concentrated extract in 60% acetone standardized for flavonoid and terpene lactone content was patented soon after as 'EGb761' and other similar commercial products followed. These standardized extracts became widely used in continental Europe, in the early 1990's becoming the most widely prescribed drugs of all in Germany and almost as widely prescribed in France. By contrast Ginkgo remains unlicensed as a medicine in the UK and is marketed as a dietary supplement there and in the USA. The evidence for the extract is mixed. This may be linked to the difficulty in defining, and achieving consensus on, the particular outcomes used in clinical research; of the many claims for ginkgo those relating to relieving dementia and peripheral symptoms of hardening arteries such as intermittent claudication (severe muscle pain on walking) are the strongest. Ginkgo has an unfortunate reputation in medical circles as a remedy that is most likely to affect bleeding problems or to interact with warfarin or aspirin: the evidence actually suggests that this may be a story that gets stronger in the telling and that ginkgo shoud be treated only as cautiously as any other plant medicine or food in issues of blood clotting.