L-theanine is a unique, water-soluble amino acid found in green and black tea leaves. It’s also found in limited amounts in certain types of mushrooms.1,2 Research has shown that L-theanine works on several different brain functions. By conducting electroencephalographs (EEG), researchers have found that L-theanine increases alpha frequency band activity in the brain. This means that it relaxes the brain without causing drowsiness.1
L-theanine can be consumed for many reasons. You can take doses of L-theanine by drinking green or black tea. However, L-theanine is also widely available as a supplement in tablet form.
L-Theanine Health Uses and Health Benefits
L-theanine benefits largely have to do with calming down brain activity. When a person takes L-theanine, it sends them into a state of relaxation. L-theanine is also believed to generate a state of wakeful relaxation, which is beneficial for improving cognitive function.2 This means that L-theanine is often considered a better alternative to caffeine because it provides the benefit of feeling awake without the jitters and nerves caused by caffeine.
Research has actually shown that L-theanine, when taken in high enough doses, has a great effect on the general state of mental alertness.1 L-theanine has also shown to have an effect on the brain by increasing dopamine and GABA levels. These are two neurotransmitters responsible for several body functions, including regulating emotions and the nervous system.2
L-theanine benefits include:
L-theanine uses include being a natural remedy for the following conditions:
L-Theanine Side Effects and Precautions
Possible L-theanine side effects include increasing the activity of chemotherapy medications. It’s also not advised to take L-theanine supplements with cholesterol-lowering medications. 2