PROBLEM TO BE SOLVED: To provide an oral agent effective for improvement of brain fatigue, such as decrease of concentration, impaired attention, impaired ability of memory learning, stress, and depression.SOLUTION: The oral agent for increasing arginine concentration in brains is provided, which contains citrulline or a salt thereof as an active constituent. As the citrulline, L-citrulline and D-citrulline are included, however, L-citrulline is preferable. As the salt of citrulline, an acid addition salt, a metal salt, an ammonium salt, an organic amine addition salt, an amino acid addition salt, and the like are included.COPYRIGHT: (C)2013,JPO&INPIT【課題】脳の疲労(集中力低下、注意力低下、記憶学習能力低下、ストレス、うつ症状など)の改善に有効な経口剤を提供する。【解決手段】シトルリンまたはその塩を有効成分として含有する脳内アルギニン濃度上昇用経口剤。該シトルリンとしては、L-シトルリンおよびD-シトルリンがあげられるが、L-シトルリンが好ましい。該シトルリンの塩としては、酸付加塩、金属塩、アンモニウム塩、有機アミン付加塩、アミノ酸付加塩等があげられる。【選択図】図1
