what is theanine used for
L-theanine (also known as just theanine) is an amino acid found in tea. It is also used in dietary supplements and is claimed to be useful for a variety of different conditions such as anxiety, Alzheimer's disease, and high blood pressure (hypertension).-theanine (also known as just theanine) is an amino acid found in tea. It is also used in dietary supplements and is claimed to be useful for a variety of different conditions such as anxiety, Alzheimer's disease, and high blood pressure (hypertension).