Ethnopharmacological relevenceThe ginseng root has been traditionally used as a sedative in oriental countries. However, the condition “ginseng abuse syndrome” (GAS), defined as hypertension, nervousness, sleeplessness, skin eruption, and morning diarrhea, was coined as a result of a study of people who had been using a variety of ginseng preparations. However, we reported that administration of RGE increased rapid eye movement (REM) and non rapid eye movement (NREM) sleep via GABAergic systems in animals. Therefore, this study was performed to investigate how red ginseng extract (RGE) affects sleeping behaviors in human volunteers. Materials and methodsRGE (1500mg) was orally administered to young male healthy volunteers (from 15 to 37 years old ages, n=15) three times a day for 7 days. Overnight polysomnographic (PSG) studies were performed two times, 1 day before and 7 days after RGE administration. We investigated differences in sleep architecture parameters such as total sleep time (TST), sleep efficacy (SE: total sleep time/time in bed), proportion of each sleep stage, and wakefulness after sleep onset (WASO) between baseline PSG and PSG after RGE administration. ResultsTotal wake time (TWT) was significantly reduced (P<0.05) and SE was increased (P<0.05), although slow wave sleep stage 1 (N1) was reduced (P<0.01) and non-rapid eye movement (REM) sleep was increased (P<0.03) after administration. ConclusionFrom these results, it is presumed that RGE intake would improve the quality of sleep, thus having beneficial effects on sleep disturbed subjects.