The use of Ginkgo complexed with phosphatidylserine for the manufacture of a medicament or a dietary supplement for the enhancement of cognitive function and alleviation of mental fatigue, i.e. to improve the speed of memory and memory quality, to increase accuracy and attention in activities in normal healthy subjects, to prevent deterioration of the speed and quality of memory in people with decreased cognitive functions, to counteract cognitive fatigue, and also having an influence on the mood, particularly in healthy children, young adults, middle-aged and/or old people. It is further provided the use of the Ginkgo-phosphatidylserine complex for the treatment and prevention of disease related with decreased cognitive function and increased mental fatigue such as Dementia, and Alzheimer's Disease.