Can You Use L-theanine for Anxiety?

Q.  Can you use theanine (aka L-theanine) for anxiety? A young woman recently told me she was using it, and said it helped, but I wasn’t sure what it was, and if it really worked. 

A. L-theanine is a common amino acid found in tea leaves and some types of mushrooms. Green teas usually contain 1 to 3 percent of L-theanine. This amino acid may help ease anxiety by increasing levels of certain relaxation promoting neurotransmitters including dopamine and serotonin, which are so-called “happy chemicals” your brain uses to elevate your mood.

There is only one study that I am aware of, which specifically evaluated L theanine for its ability to help people with anxiety, published in Human Psychopharmacology in 2004. This study split 16 healthy people into three groups. One-third of the participants received alprazolam, a common medication prescribed to reduce anxiety and panic attacks; one-third of the people took L-theanine; and the last one-third took a placebo. The participants self-reported their anxiety levels during a relaxing situation and during a scenario created to make the participants anxious. None of the participants were able to relax during the experimentally induced anxiety section of the study. Both the people taking L-theanine and those taking alprazolam felt more tranquil overall during the relaxing portion, in comparison to the placebo group.

This is a very small, preliminary study, and it really only evaluates the short term effects of both alprazolam and L-theanine in a fairly artificial setting - acute, short term experimentally produced anxiety. I find it interesting that in this study even alprazolam, which is a well-known anti-anxiety medication, did not help the participants during the experimentally induced anxiety situation. What this study does point out is that L-theanine probably does help with promoting relaxation, but there are no studies to date looking at L-theanine for more chronic anxiety conditions.  However, if your anxiety is mild, by all means, sit down, take some deep breaths, and enjoy a cup of green tea.