L-theanine is an amino acid, a.k.a. a molecule that helps build protein in the body. It’s known for being found in green tea, but it's also in other herbal brews such as white, black and oolong teas.

The amino acid l-theanine found in green tea is widely used in China, Japan, and other Asian countries to treat anxiety and depressed mood. Animal studies confirm that l-theanine increases brain ...

L-theanine, a distinctive non‐protein amino acid predominantly found in green tea, has garnered significant attention for its multifaceted roles in modulating immune function and mitigating ...