L-Theanine can have a direct influence on our brains, increasing so-called Alpha Brain Waves, which are only present when we are alert and relaxed. It helps regulate calming neurotransmitters, dopamine, serotonin and GABA – and simultaneously inhibits the effects of the “stress hormone” norepinephrine. All this allows it to help improve mood, sleep and learning capacity, while reducing the feeling of being stressed.