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.
There are no known side effects of this product. However, this probably reflects a lack of clinical studies with L-
theanine (not a real absence of side effects).
(Click L-Theanine Side Effects to learn more, including what to do if you develop a potentially serious side effect.)
Drug Interactions With L-Theanine
Some people may be more likely to experience problems due to this supplement. Therefore, you should talk with your healthcare provider before taking it if you have:
- Kidney disease, such as kidney failure (renal failure)
- Liver disease, such as liver failure, cirrhosis, or hepatitis
- Any other serious or chronic health condition
- Any allergies, including allergies to food, dyes, or preservatives.
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click L-Theanine Safety for more information, including any available warnings and precautions.)
What If I Take an Overdose?
It is not known exactly what to expect from an overdose of this product. If you think you may have taken too much, seek medical attention immediately.
Storage Methods for L-Theanine
Refer to the label of your individual product for information on how to best store L-
theanine. Keep L-theanine and all other medications or supplements out of the reach of children.