Healthy Origins® American-Made L-Glutamine is an amino acid produced by the body to serve as a building block for proteins. It also helps supply fuel to the immune cells inside your GI tract. L-Glutamine is the most abundant amino acid found in your blood and muscle tissue. However, during times of stress or rigorous exercise, your natural levels of L-Glutamine may be reduced. For this reason, many athletes choose to add supplemental L-Glutamine to their diet and exercise regimen. L-Glutamine may help to optimize athletic performance, support muscle health, and support healthy immune cell function.*