L-Theanine is also said to increase mental awareness, cognition, and concentration.

L-Theanine may contain mast cell-stabilizing properties in an animal model.

L-Theanine - a unique amino acid of green tea and its relaxation effect in humans.

The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans.

Research suggests that tea's combination of caffeine and the amino acid L-theanine can improve alertness, reaction time, and memory.

In addition black tea, which contains L-theanine, is credited in one study with mobilizing the immune system's disease-fighting T-cells.

Tea may be consumed early in the day to heighten calm alertness; it contains L-theanine, theophylline, and bound caffeine (sometimes called theine).

Like many other energy drinks, NOS contains high levels of taurine, and caffeine, but differs via its inclusion of large amounts L-Theanine.

Michael Lyon, head of the Canadian Centre for Functional Medicine in Vancouver, believes that L-Theanine "is the best-kept secret in natural medicine".

The amino acid L-theanine, found almost exclusively in the tea plant, actively alters the attention networks of the brain, according to results of human trials announced in September 2007 .

Certain Other Supplements: Hypericum perforatum ("St John's Wort"), Inositol, Rhodiola rosea, S-Adenosyl-L-Methionine (SAMe), L-Theanine.

Common ingredients in relaxation drinks may contain kava root, melatonin, valerian root, gamma-aminobutyric acid (GABA), Chamomile, Melissa officinalis, L-Theanine, L-Threonine, 5-Hydroxytryptophan or Passiflora.

In addition to caffeine, guayusa also contains theobromine, a stimulant commonly found in chocolate, and L-theanine, a glutamic acid analog found in green tea that has been shown to reduce physical and mental stress.