17 publications reporting nine individual studies, all using the standardized extract EGb 761®, met our inclusion criteria (Figure (Figure1).1). EGb 761® is a dry extract from Ginkgo biloba leaves, extraction solvent: acetone 60% (w/w). The extract is adjusted to 22.0-27.0% ginkgo flavonoids, calculated as ginkgo flavone glycosides and 5.0-7.0% terpene lactones consisting of 2.8-3.4% ginkgolides A, B, C and 2.6-3.2% bilobalid. It contains less than 5 ppm ginkgolic acids. There was no study with other ginkgo product that met our inclusion criteria.