A nutritional supplement composition for enhancing cognitive function includes Ginkgo biloba, rhodiola, acetyl-L-carnitine and huperzine A. The Ginkgo biloba, rhodiola and acetyl-L-carnitine are in a ratio a:b:c respectively such that a as the Ginkgo biloba is between about 690 and 1030, b as the rhodiola is between about 1,700 and 2,600 and c as the acetyl-L-carnitine is between about 8,000 and 12,000. The composition is formulated for oral administration and the Ginkgo biloba, rhodiola, acetyl-L-carnitine and huperzine A together account for at least 80 wt % of a dosage unit of the nutritional supplement composition.