How Does L-Theanine Work?
It is not exactly clear how the amino acid works. It might work for anxiety by increasing levels of
gamma-aminobutyric acid (
GABA), a brain chemical that is naturally calming. It may also increase serotonin levels in the brain. It is thought that the substance may also protect nerves in the brain from damage seen with
Alzheimer's disease. In animals, it lowers norepinephrine levels, which may help
lower blood pressure.
There is not yet enough scientific evidence to evaluate the effectiveness of L-theanine for any use.
A safe and effective dose of this supplement has not been established.
Be sure to follow the specific instructions on your particular product.