Ingredient Description

L-theanine is a non-essential amino acid that occurs primarily in leaves of the plant Camellia sinensis, which is used to produce black, oolong and green tea. People have used L-theanine and green tea historically as a way to reduce stress while remaining alert and avoiding drowsiness. A study published in the January 2007 issue of "Biological Psychology" found that L-theanine intake resulted in reduced heart rate and salivary responses to a stressful task when compared with a placebo. Drugs.com cites a Japanese study showing that L-theanine promotes alpha brain waves, an indicator of alert relaxation.