I have been taking L-Theanine twice a day, 200 mgs am and pm for about a month. Just ordered 2 month's worth from Amazon. I do not take GABA. Most GABA in supplements is not bio-available. The L-Theanine helps the body with GABA. L-Theanine, L-Tryptophan and even a small amount of caffeine ( a single serving in the am) can help the three most important neurotransmitters needed for good brain function. (serotonin, dopamine, and norepinephrine) Acetylcoline is also important.

Can't say if it is helping because I also started another med at the same time. We'll see when I try to go off the med in a few months after a major stressor in my life is resolved.

My sister swears by the improvements she sees from taking L-Theanine.