L-Theanine is a non-protein amino acid exclusively found in tea plants. It is the major amino acid found in green tea leaves and the one responsible for the signature umami taste of the world’s most consumed beverage. Despite containing caffeine, tea is known to give calming and relaxing effect which is also attributed to having high levels of natural l-theanine. Approximately, 1-2% of the weight of tea leaves is purely this neurologically-active amino acid.
The medicinal and nutritional value of L-theanine is due to its ability to regulate the levels of three important neurotransmitters (brain chemicals) namely: GABA (gamma-aminobutyric acid), Serotonin, and Norephinephrine. L-theanine increases the production of GABA, a major inhibitory neurotransmitter that naturally generates a feeling of calmness and relaxation. L-theanine affects serotonin just like GABA. Serotonin is responsible for controlling emotions like happiness and anger. When there is more serotonin made and distributed in the bloodstream, the better you will be at controlling your emotions. Opposite to the first two neurotransmitters, l-theanine decreases norepinephrine levels in the body. When released, norephinephrine occurs a “fight-or-flight” status in which the body becomes extremely alert. Decreased norepinephrine reduces anxiety, hypertension, and stress which are results of the “fight-or-flight” state.
L-Theanine Side Effects
According to l-theanine reviews, there are only few possible known l-theanine side effects including headache, upset stomach, and dizziness.