Study Title:

Theanine and Sleep

Study Abstract

From press release:

Taking a pure L-theanine supplement (as Suntheanine from Taiyo International Inc., distributed by Fairfield, Conn.- based NutriScience Innovations LLC) may help improve sleep, according to the company. The results of the study will be presented at the 17th European Sleep Research Society Congress this October in Prague.

After a three-day acclimation period, 22 young men (with an average age of 27) were supplemented with 200 mg/d of Suntheanine or placebo one hour before bedtime for six consecutive days; subjects were then crossed over and received the opposite treatment. Sleep performance was assessed by interviews upon waking, questionnaires and a wrist actigraph, which records bodily movement during sleep. During administration of Suntheanine, all subjects reported a statistically significant absence of feeling exhausted and a reduced need for sleep compared to when receiving placebo, according to Taiyo International. Sleep efficiencyan index of actual sleep time enjoyed between the time of falling asleep and final morning awakeningalso improved in several subjects; these same subjects also reported a superior mental state prior to falling asleep and a decreased occurrence of nightmares during the Suntheanine phase, but not the placebo phase. The total time from falling asleep to awakening was unchanged during both phases of the study.

Study Information


Suntheanine May Support Sleep

2004 April

Full Study