Theanine by Thorne Research

L-theanine is a unique amino acid that is found almost exclusively in the tea plant (Camellia sinensis) and which has been used safely in Japan for decades. L-theanine has been shown to positively modify brain waves and the key neurotransmitters involved in mood, focus, and memory. L-theanine enhances the production of the neurotransmitters dopamine and serotonin, and also appears to play a role in the formation of GABA – a neurotransmitter that acts like a "brake" during times of runaway stress. L-theanine also enhances brain alpha-wave activity, a marker of relaxation. This effect has been observed to be most pronounced in individuals subjectively feeling the highest levels of stress.A Japanese study of university students found that 200 mg of L-theanine led to increased brain alpha-waves and a subjective sense of relaxation. In the same study, L-theanine administration also caused a dose-dependent relaxed, yet alert, state of mind without sedation, beginning approximately 40 minutes