Theanine 100 mg 60 caps by Jarrow Formulas is a beneficial dietary supplement for anyone who is a multi-tasking. type A personality and needs a natural way to relax. The unique amino acid found in Theanine 100 mg 60 caps works to increase the level of both dopamine and serotonin in the brain. promoting a feeling of relaxation without the negative side effect of feeling drowsy. This action also helps improve the ability to learn.