There are no concrete studies that has determine the actual dose of Ginkgo extract to achieve an actual benefit. The components of ginkgo ( flovanol glycoside, terpenes) do not significantly inhibit human cytochrome P450 isoforms in vitro liver microsomal studies, and the clinical important of this information is unknown. Absorption has been through the small intestine. Studies have shown half-life of ginkgolides A and B, bilobalide are 4.5, 10.6, and 3.2 hours with peak levels at 2-3 hours. Most studies of ginkgo extract used the standardized extract of EGb 761, with standardized contain of 24% flavonoid glycoside and 6% terpenoids. The typical dosage is as follows EGb761 used, containing 40mg three times per day, or 80mg twice daily
