L-theanine is a unique amino acid found in the green tea plant. Just as adrenaline causes the release of cortisol, theanine acts as the precursor to dopamine in your brain. Dopamine is the second largest brain chemical, and plays a key role by preventing your brain from accessing adrenaline. Since the brain is unable to access adrenaline, cortisol release is restricted.
Not only does theanine have the potential to prevent the body from elevating cortisol, but it rewards you by stimulating relaxing alpha waves in your brain. This allows your brain to focus, prioritize thoughts, improve concentration, and increase learning
ability while you’re awake.
At night, theanine helps your brain shut down, and allows you to get a better night’s sleep instead of racking your brain with a slew of problems. Although theanine can’t repair its effects, the amino acid can help alleviate stress from adrenal exhaust.†