A composition for recovery from or prevention of central nervous system fatigue (brain fatigue), comprising as active ingredients at least any amino acid selected from the group consisting of tyrosine, methionine, phenylalanine and glutamine, especially methionine and phenylalanine together with a branched chain amino acid of L-valine, L-leucine or L-isoleucine. This composition is provided as an injection agent or fluid infusion, or as, through addition of an appropriate vehicle such as starch or lactose, a solid dosable form (pharmaceutical application) such as tablets, granules or powder, or as any of various drinking water forms (food application) such as those known as health drink.