Theanine Serene (Source Naturals) Each bottle, 120 tablets. Each TWO tablets contain:
GABA (gamma-amino-butyric acid) - 500 mg
Taurine - 500 mg
L-Theanine - 200 mg
Holy Basil Leaf Extract - 100 mg

Theanine is an amino acid found in green tea, also known as N-ethyl-L-glutamine. It has been shown in the test tube to protect neurons against damage caused by glutamic acid (by blocking the receptors in the brain where glutamic acid would bind) and oxidation of low density lipoprotein (LDL or bad cholesterol). A recent study showed it to be very safe with a no-observed-adverse-effect-level (NOAEL) of 4000 mg per kilogram of body weight per day, the highest dose tested (Food Chem Toxicol, 2006 Jul;44(7):1158-1166).

It acts as a relaxing agent by increasing levels of various brain chemicals (neurotransmitters) including serotonin, dopamine and GABA (gamma amino butyric acid). Behavioral studies in animals suggest it may improve learning and memory. Human studies are largely lacking, so far. One small study, placebo controlled but only among 7 participants, showed a decrease in heart rate as well as a reduction in salivary sIg-A production, indicating a calming of the sympathetic nervous system activation, underscoring a potential mechanism for its anti-stress activity (Biol Psychol, 2007 Jan;74(1):39-45. Epub 2006 Aug 22.). Interestingly, a mouse study suggested that the use of theanine may enhance the tumor-suppressive effects of chemotherapy drugs like doxorubicin (Biochim Biophys Acta, 2003 Dec 5;1653(2):47-59).

Taurine is also an essential amino acid that may protect against oxidative stress, neurodegenerative diseases or atherosclerosis (Curr Opin Clin Nutr Metab Care, 2006 Nov;9(6):728-733). Like N-aceytlcysteine (NAC), taurine is a sulfur-containing amino acid. It may also have some benefits for liver function.

Contains wheat. Do not use if pregnant or if using other MAO or serotonin-reuptake inhibitors.