The Green Tea Ingredient That Could Help You Drift Off More Quickly

If a natural supplement could improve sleep without leaving you groggy the next day, would you try it?

Scientists tested L-theanine, the amino acid found in green tea that is linked to its soothing effect. In the study, 30 people took either 200 mg of L-theanine or a placebo before bed for four weeks. After a two-week washout period, they switched to the other treatment. In other words, every participant eventually completed both parts of the trial.

The study was double-blind, so neither the researchers nor the participants knew who was receiving which treatment. Compared with placebo, L-theanine shortened the time it took to fall asleep, reduced overall sleep disruptions, and lowered the need for sleep medication. It also improved daytime dysfunction, which can include difficulty staying awake during the day and a lack of motivation for productive tasks.

The findings line up with how L-theanine is thought to work. Even though it may improve sleep quality, it is not considered sedating. Instead, it tends to promote a calm, balanced feeling. It is even added to some energy drinks to soften the effects of caffeine. L-theanine products are usually promoted as stress-reducing supplements rather than sleep aids.

There were signs of improvement in depression as well, but the results were not statistically significant compared with placebo. The study was small and did not take other lifestyle factors, such as diet, into account. It was also funded by a company that produces L-theanine products. Even so, the results are encouraging. Because L-theanine is relatively inexpensive and generally considered safe, it may be a low-risk option for people hoping to sleep better.