Theanine is an amino acid found naturally in tea. Besides caffeine, theanine has been identified as a major component of tea. While younger and fresher tea leaves tend to be richer in caffeine, older leaves tend to have higher theanine levels; furthermore, the withering process of tea production also increases theanine content.
Some evidence suggests that theanine affects mental performance and reduces blood pressure. Research has examined the cognitive effects of this substance alone and when combined with caffeine.
2-Amino-4-(ethylcarbamoyl)butyric acid, 2,4-dinitrophenyltheanine derivative (DNP-theanine), 5-N-ethylglutamine, amino acid theanine (5-N-ethylglutamine), black tea (Camellia sinensis), D/L-theanine, D-theanine, epitheaflavic acids, gamma-glutamylethylamide, green tea (Camellia sinensis), L-N-ethylglutamine, L-theanine, oolong tea, Suntheanine®, theaflavins, thearubigins.
Select combination products: Theanine Serene™ (theanine, valerian, taurine).
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Theanine has historically been used as a relaxing agent. Limited research suggests that theanine may have a slight relaxing effect but not significantly reduce anxiety. Additional research is needed in this area.
Blood pressure control
Limited research suggests that theanine may counteract the effect of caffeine on blood pressure. Additional research is needed in this area.
The mood effect of theanine has been examined when combined with caffeine. Theanine alone had few effects on mood. The combination of theanine and caffeine had improved mood effects not seen with either treatment alone. Additional research is needed in this area.
The effect of theanine on cognition (mental performance) has been examined when combined with caffeine. Theanine alone slowed overall reaction time. The combination of theanine and caffeine had improved mood effects not seen with either treatment alone. Additional research is needed in this area.