L-Theanine Benefits

L-Theanine (also called theanine) is an amino acid found in green and black tea. In recent years, L-Theanine effects on anti-stress effects and sleep quality improvement have attracted more attention, it has been used in many food and beverage products.

L-Theanine Benefits

So what is L-Theanine benefits? Why it is more and more popular?

L-Theanine benefits

Inhibits the stimulant effects of caffeine

Tea gives people a “warm body and mind”, “peace of mind” feeling. Previous studies have shown that L-theanine can act on the human brain and exert an effect that inhibits the stimulation of tea caffeine.

It is well known that the caffeine contained in tea and coffee has the effect of causing nerve excitement and awakening the brain. While theanine in tea can relieve the stimulant effect of caffeine, it has been confirmed that the beta waves (brain waves that occur in the excited state) that occur when caffeine is consumed are inhibited by L-theanine.


Human sympathetic nerves are stimulated when drinking water, which in turn produces a relaxing effect. However, when drinking water, the relaxation effect is short-lived, but when drinking water contains theanine, the relaxation effect can last for nearly one hour.

A research on relaxation effect from Aichi Shukutoku University provided us proof. This study involved eight volunteers, which was randomly divided into a water drinking group containing 50mg of theanine and a water drinking group containing 200mg of theanine. The results showed that alpha waves appeared in the head rear and top area of the subjects who are in the drinking group of theanine 200mg. In the drinking group of theanine 50mg, the power value of the alpha band in the high anxiety domain increased. From this study, it can be concluded that theanine has a relaxing effect.

Alpha waves are brain waves that occur when people relax, taking theanine caused alpha waves appear and increase, thereby indicating that theanine has a relaxation effect.


Improving sleep quality

Theanine has a certain effect on sleeping difficulties and waking up in the middle of the night. About the effects of theanine on sleep, research results released by the Institute of Mental Health of the National Mental Neurological Center of Japan.Although the difference is not particularly significant, it shows a better tendency to fall asleep under L-theanine conditions, which means that L-theanine is likely to have an effect on sleep. From the point of view of sleep efficiency, the L-theanine condition was significantly improved to 96.6 % compared to 93.8 % in the placebo group. This result shows that L-theanine not only extends sleep time, but also shows the potential to improve sleep quality.

theanine improves sleep quality

Stress Reduction

L-theanine may help reduce stress. A study subjected twelve male college students to arithmetic problems for twenty minutes. The participants rated this activity as causing an increase in stress. The participants taking 200 mg of L-theanine reported a reduced stress response from the stress test (performing arithmetic problems) and showed a reduced physiological stress response compared to those taking a placebo.

L-Theanine side effects

No health damage or side effects of L- theanine have been reported so far. Also, L-Theanine can be used as a dietary supplement and has been granted GRAS (generally recognized as safe) status by the Food and Drug Administration (FDA).

L- Theanine recommended dose is 200 mg daily .

Purelife bio supply L-Theanine with all kinds of specs (purity), this raw material is also stocked in our USA warehouse, we are willing to serve global customers at any time.