NOW® Ginkgo Biloba is grown and extracted under the highest quality standards and is standardized to 24% ginkgoflavonglycosides and minimum 6% terpene lactones, including Ginkgolide B, the most significant fraction and Ginkgolides A, C and Blobatide. Our Ginkgo Biloba Extract is the finest quality available worldwide. Scientific research has demonstrated that Ginkgo Biloba Extract has antioxidant activity in in vitro studies.