What Is L Theanine Used for?

L Theanine is an amino acid. It is found in tea and in particularly high concentrations in Gyokura (a type of green tea). L Theanine has been the subject of considerable study in Japan, though its introduction to the United States has been relatively recent. It is believed that L Theanine plays a role in increased production of GABA, serotonin and dopamine. It is commercially available in the US as a nutritional supplement, though it is not FDA-approved to treat any condition.

Relaxation

• L Theanine is reported to encourage a relaxation state by helping to induce alpha wave brain states (a brain wave state associated with relaxation).

Blood Pressure

• L Theanine helps to lower levels of noradrenaline (norepinephrine), a hormone that stimulates the nervous system. Lowering the levels of noradrenaline may help to lower blood pressure.

Cognitive Function

• There is some evidence that suggests that L Theanine may help to protect brain cells from damage. The potential increase in neurotransmitters (serotonin and dopamine) may also contribute to improved cognitive function.

Immune Support

• L Theanine is also reputed to help improve immune function though increased T cell function and anti-bacterial actions.

Safety

• L Theanine is considered to be non-toxic--even in high dosages--and has no known adverse reactions. Generally, it is not recommended for use by children.

Theories/Speculation

• There is some speculation that L Theanine might work as an alternative treatment for ADHD, but the research remains limited.