Compositions for improving sexual function

Method of improving sexual function of a sexually healthy human subject on demand, comprising:

• administering a composition or unit dosage comprising L-arginine and L-citrulline or a physiologically acceptable salt or hydrate of any one thereof, wherein the content of L-arginine or a physiologically acceptable salt or hydrate thereof is at least 4.0 g and the content of L-citrulline or a physiologically acceptable salt or hydrate thereof is at least 1.0 g, wherein sexual function is improved for a time period of up to 6 hours.