Abstract: At least one of alertness, attention, focus and concentration may be enhanced in a person in need thereof, by a method including a step of administering a composition to the person, where the composition includes: a) between 20 mg and 5 g per dose of mangiferin, norathyriol, or an extract comprising mangiferin or norathyriol sufficient to provide between 20 mg and 5 g mangiferin or norathyriol per dose, wherein said extract comprising mangiferin or norathyriol is a mangiferin-containing extract of a plant species in a genus selected from the group consisting of Mangifera, Salacia, Cyclopia, Hypericum, Canscora, Fagraea, Gentiana, Hoppea, Swertia, Hypericum, Polygala, Zizyphus, and mixtures thereof; and b) caffeine.

Abstract: A method for enhancing at least one of alertness, attention, concentration and memory in a person in need thereof, comprising co-administering an effective amount of mangiferin, norathyriol, or an extract comprising mangiferin or norathyriol; and caffeine to the person. The components may be co-administered in a single composition, or administered in separate compositions. The mangiferin and/or norathyriol exhibit synergistic effects on brain wave activity when co-administered with caffeine.

Abstract: A method for enhancing at least one of alertness, attention, concentration and memory in a person in need thereof, comprising administering a composition to said person, said composition comprising: a) an effective amount of an extract of Cyperus esculentus peel, Cyperus esculentus rhizomes, or a combination thereof; b) an effective amount of mangiferin, norathyriol, or an extract comprising mangiferin or norathyriol; or c) a synergistic combination of (a) and (b).