PROBLEM TO BE SOLVED: To provide a means for improving bad lifestyle due to failure in biological clock and preventing, treating or improving (alleviating) symptom or disease due to failure in biological clock, such as sleep, body temperature, blood pressure, hormone secretion, feeding and the like, with oral feeding.SOLUTION: There are provided an oral biological clock adjusting agent comprising one or more selected form a group consisting of myoinositol, pinitol, acnegia, bupleurum root, yokukansan, Bu Zhong Yi Qi Wan, Meridian-Warming Decoction, conditioned Guipi Wan, ergothioneine, and TAHEEBO, and a composition for improving symptom or disease due to failure in biological clock comprising it, as well as a screening method for the oral biological clock adjusting agent in which increment in amplitude in biological clock is used as an indicator.COPYRIGHT: (C)2015,JPO&INPIT【課題】体内時計の不調による生活リズムの乱れを改善し、睡眠、体温、血圧、ホルモン分泌、摂食その他、体内時計の不調に起因する症状又は疾患を、経口摂取により、予防、治療、又は改善(緩和)するための手段を提供すること。【解決手段】ミオイノシトール、ピニトール、acnegia、柴胡、抑肝散、補中液気湯、温経湯、加味帰脾湯、エルゴチオネイン、及びTAHEEBOからなる群より選ばれるいずれか1又は2以上を含む、経口摂取可能な体内時計調節剤及びこれを含む体内時計の不調に起因した症状又は疾患を改善するための組成物、並びに、体内時計の振幅上昇を指標とした経口摂取可能な体内時計調節剤のスクリーニング方法。【選択図】なし