L-theanine is considered an non-essential amino acid, which the body does not naturally produce. It is known to promote relaxation without the effects of drowsiness.
L-theanine can be found abundantly in green and black tea. Studies have suggested that L-theanine has certain effects on the brain chemicals which helps reduce one's stress and anxiety, thus promoting restful sleep but without any drowsiness. Therefore, this nutrient is ideal in today's fast-paced, stressful society to relax without compromising alertness to meet the day-to-day demands.