Cognitive Health With Ginkgo Biloba Extract GMP Quality Assured A Dietary Supplement General Health Family Owned Since 1968 NOW Phosphatidyl Serine with Ginkgo Biloba combines two ingredients that can help to support healthy mental activity. Phosphatidyl Serine (PS) is a naturally occurring phospholipid derived from soy that plays a critical role in proper cellular membrane function. It is especially important in the brain and nervous system where PS is critical for mental functions such as memory, attentiveness, and reaction time. Ginkgo biloba may support brain health through its powerful free radical scavenging activity, as well as through other biological mechanisms.