L-Theanine
- A kind of primary amino acid found in
green tea leaf
- Functional effect : Can help relieve
stress
- Daily Intake : 200~250mg as L-Theanine
What is Theanine?
Theanine is a kind of natural amino acid
contained in green tea leaf, as a taste component that provides flavor, sweet
and savory taste of green tea leaf. From old times, green tea leaf has been
known as having effect of mental stabilization. It was found that the effect is
caused by the component named Theanine. Normally, it accounts for about 1~2% of
dried leaf, having the structure of gamma-glutamilethylamide.

ㅣL-Theanine contained in green tea leaf
Effect of Theanine
1. Relieving
tension, stress and anxiety
Theanine helps increase α wave created when one feels convenient and stable.
This has the effects of relieving tension and anxiety caused by stress.
2. Improving premenstrual syndrome
According to a Japanese university and a lab, the intake of 200mg of L-Theanine
results in improving mental problems such as lethargy, anxiety, restlessness
and difficult concentration caused by premenstrual syndrome, as well as PMS
including headache, fatigue and cold feet/hands.
3. Increasing serotonin and dopamine value
Theanine is known as influencing on substances such as dopamine or serotonin
working on brain nerve cells.
4. Effects of relieving insomnia and
improving quality of sleeping
As Theanine has the effects of suppressing brain excitability and relieving
nerves, it ensures pleasant sleeping. The intake of Theanine before sleeping
will remove tension and stress to smoothly switch over to sound sleep.
5. Increasing the brain activity and
helping increase cognitive ability.
Studies on Theanine
1. Time for tea: mood, blood pressure and cognitive performance effects of
caffeine and theanine administered alone and together.(Rogers PJ1, Smith JE.
Psychopharmacology (Berl). 2008 Jan;195(4):569-77. Epub 2007 Sep 23)
: The results of a study on subjective perception, activity and blood
pressure, showed that the intake of L-Theanine and caffeine has the effects of
suppressing the increase in blood pressure caused by caffeine which is
L-Theanine.
2. The deployment of intersensory selective attention: a high-density
electrical mapping study of the effects of theanine. (Gomez-Ramirez M1, Higgins
BA, Rycroft JA. Clin Neuropharmacol. 2007 Jan-Feb;30(1):25-38)
: It was revealed that the intake of L-Theanine resulted in the increase in
α wave to relieve stress.
3. L-Theanine reduces psychological and
physiological stress responses.(Biol Psychol. 2007 Jan;74(1):39-45. Epub 2006
Aug 22)
: It was found that the intake of
L-Theanine has the stress relieving effect by suppressing the stimulation of
nerve cells of cerebral cortex.
4. L-theanine and caffeine improve task
switching but not intersensory attention or subjective alertness. (Einher SJ1, Martens VE. Appetite. 2010 Apr;54(2):406-9. doi:
10.1016/j.appet.2010.01.003. Epub 2010 Jan 15.)
: It was found that the intake of L-Theanine and caffeine together has the
effect on improved attention.