L-theanine is an amino acid with a purpose to help ease anxiety, stress, and reduce insomnia.

Research suggests that L-theanine may improve the function of the body’s immune system. With a study finding that L-theanine could help decrease upper respiratory tract infections, evidence also suggests that L-theanine could help improve inflammation in the intestinal tract.

Other benefits of L-theanine include:

  • May be beneficial for those who experience increased blood pressure in stressful situations
  • Researchers found that doses of 250 mg and 400 mg of L-theanine greatly improved sleep in animals and humans