Glutamine plays key roles in protein synthesis, providing energy to the cells, pH balance in the kidneys, and a part of several anabolic processes. Despite the fact that the body regularly produces glutamine, supplementing the diet with glutamine and L-glutamine can enhance the efficiency of these processes.

For bodybuilders, L-glutamine in particular appears to play an important role in maintaining muscle mass, as the higher levels through the body prevents the leaching of L-glutamine from muscle tissue for other processes. Because of its role in cellular energy and anabolic mechanisms, bodybuilders often use a great deal of their natural glutamine and L-glutamine while exercising.

The body can replenish this by breaking down muscle, and to prevent this, a glutamine or L-glutamine supplement can be used. The supplement may not only halt or slow down the rate of muscle deterioration, but may also increase the protein synthesis required to build muscles and also increases body immunity.