Theanine is a common amino acid found in green tea, and the particular molecule we’re interested in is commonly referred to as L-Theanine (chemists in the group will understand what the “L” stands for). It was first extracted and isolated from green tea leaves in the 1950’s, and is generally regarded as safe and approved for general population consumption (it’s basically tea!).
Theanine is able to cross the blood-brain barrier, and acts similarly to coffee in many respects. It has been shown to reduce mental and physical stress, as well as increasing focus and cognition.
L-Theanine is one of the premiere active components in green tea (this is partly why green tea is so good for you), and when extracted from tea leaves is now a popular, safe supplement found in both aids to focus and concentration, as well as relaxation and mild tranquilization (ie: natural antidepressants).
It’s these relaxation and tranquilization characteristics that have made L-Theanine a popular addition to many “natural” sleep aids. The one that I use occasionally has a mixture of melatonin (1.5mg), 5-HTP (15mg), and L-Theanine (100mg).
It’s basically harmless, and it could have an impact on your relaxation for sleep, or your concentration for study!