L-Theanine is an amino acid that preliminary evidence suggests may help ease some psychological and physical aspects of normal everyday stress, including occasional anxiety and tension. Human studies have shown that taking L-theanine affects the emission of alpha waves in the brain associated with states of relaxation and focused attention. Preliminary research has shown that L-theanine crosses the blood brain barrier, and suggests that it may support healthy neurotransmitter levels in the brain, and inhibit the stimulatory properties of caffeine.

Works well in calming me when I need it. Good product.

Helps me too sleep. I combine with Gaba. Good Brand.

Cant say enough about this pill. With someone who has high cortisol and adrenaline it has really helped me.

Easy to swallow. Works fast. Suntheanine is supposed to be better.

I like these tablets from Source Naturals because they are 200mg, so 60 tablets go a long way. They are ideal to either combine with a cup or coffee for the synergistic effect, or standalone to induce a calming reaction, especially when you are feeling panicky; having racing thoughts, ...

Source Naturals Brand L-Theanine may have a slight edge in terms of effectiveness when compared to other brands of L-Theanine. Most likely I'll try this brand again.

I've used this product for several years and am satisfied with it. However, it is the first time I've ordered from iHerb and the quick delivery was remarkable.

This supplement has proved itself. I no longer have to take blood pressure tablets. I have been on this supplement for many months and continue to have great blood pressure readings.

it works!! Take it for sleep!