L-Theanine is an amino acid found most commonly in tea leaves and in small amounts in Bay Bolete mushrooms. It can be founding in both green and black tea. It’s also available in capsule or tablet form.
Research indicates that L-theanine promotes relaxation without drowsiness.
A calming effect is usually noted within 30 to 40 minutes after L-theanine is taken at a dose of 50 to 200mg, and typically lasts from 8 to 10 hours. It is also suggested that moderate anxiety symptoms often improve with a regime of 200mg once or twice daily.
L-theanine crosses the blood-brain barrier, and has the ability to modulate inhibitory neurotransmitters, selective serotonin, and dopamine to bring about anxiolytic and calming effects. L-theanine can also improve cognition and select attention, perhaps due to the changes in alpha brain wave activity.
Known for it’s Alpha brain-boosting abilities. L-Theanine can help our brain and body enter the first stage of NREM sleep, where there is a high level of alpha brain waves.
There is also some suggestion that L-Theanine can provide support to your Liver - Ref - Published Paper from Anhui Agricultural University in China.