L-theanine is an amino acid found in green and black tea and commonly used as a natural stress reliever. In addition, it can help to improve concentration and focus without making you feel sleepy. As a psychoactive substance, L-Theanine can easily cross the blood-brain barrier, directly working its magic on the central nervous system.L-theanine is especially beneficial for anxiety sufferers because it increases dopamine and GABA (gamma-aminobutyric acid) receptors in the brain. GABA is a chemical receptor that reduces the activity of neurons that it binds to. In other words, it helps slow down the feelings of fear and stress when neurons become over excited.CanPrev’s L-Theanine provides an impressive 250 mg of pure L-theanine along with 20 mg of magnesium bisglycinate to promote a state of relaxation so that you can stay focused and productive.