Source Naturals l-Theanine is an amino acid that preliminary evidence suggests may help ease some psychological and physical aspects of normal everyday stress, including occasional anxiety and tension. Human studies have shown that taking l-theanine affects the emission of alpha waves in the brain associated with states of relaxation and focused attention.L-theanine, a natural constituent in tea, and its effect on mental state. Nobre AC(1), Rao A, Owen GN. Author information: (1)Unilever Food and Health Research Institute, Olivier van Noortlaan 120, Postbus 114, 3130 AC Vlaardingen, The Netherlands. Tea is the most widely consumed beverage in the world after water.L-Theanine, a unique amino acid commonly found in green tea, provides a natural form of stress relief and is known to reduce anxiety and improve concentration. L-theanine naturally stimulates Alpha wave generation in the brain, to help you achieve an awake, alert and relaxed physical and mental state.The best natural way to obtain L-theanine is to drink several cups of quality green tea and others teas every day. L-theanine is safe when taken in supplement form but will reduce effects of blood pressure medications and stimulants. The typical dosage is between 100–400 milligrams per day.Suntheanine contains pure L-theanine, a unique amino acid found in green tea that supports mental calmness and relaxation. Suntheanine is produced via a proprietary enzymatic process guaranteeing essentially pure and natural L-theanine for maximum effectiveness.Available as a dietary supplement, theanine is used to boost focus and concentration as well as to promote relaxation. The amino acid is found in rich amounts exclusively in tea. Research suggests it may enhance brain function and help your body deal with stress. While consuming theanine from tea is …L-theanine’s effect on the brain can be visualized on an EEG. Brain waves are actually smoothed out—but not flattened out—by supplemental L-theanine. 16 The body is relaxed, the mind is calmed, but no drowsiness occurs. 5 This is exactly the type of relaxation prescribed by sleep therapists.L-theanine has positive effects on both the mental and physical symptoms of stress, including lowering heart rate and blood pressure. Research suggests that L-theanine can help reduce anxiety in …