L-Theanine is an important substance in green tea. It is an amino acid that is related to nerve impulses. It helps with relaxation. It was discovered in Japan. It is safe and meets standards. It works in the brain. It was found that L-Theanine can increase serotonin, dopamine, and GABA.It increases learning and memory, helps the brain release alpha brain waves and reduces beta brain waves, resulting in relaxation and stress reduction, and promotes a calm mind, resulting in better work efficiency. Many Japanese and Chinese people, even monks, like to take L-Theanine because it makes the mind peaceful. L-Theanine is therefore a widely popular dietary supplement worldwide.