L-Theanine is a naturally occurring amino acid found in green tea, with the ability to cross the blood-brain barrier.
Theanine has been shown to be responsible for the calmative effects of Green Tea, that are known to induce a relaxed but alert state. This resulting calmative state without sedation is what makes L-Theanine such a popular nootropic to combine with stimulants due to the "flow-state" that results.
L-Theanine has been shown to assist with the following:
Not only does L-theanine also has positive effects on stress levels but has also been shown to have effects on the levels of both dopamine and serotonin in the brain.