GNC fulfills its commitment of excellence to you by ensuring that only products of the highest quality reach you, the consumer. For us, each and every step matters to ensure that what you consume under the GNC brand enables you to live well. Glutamine, a non-essential amino acid, is one of the most abundant amino acids found in muscles. It plays an important role in muscle function during and after exercise. Each serving of GNC L-Glutamine powder supplies 5,000mg of L-Glutamine and blends easily with and beverage or sports drinks. It serves as fuel for the immune system and maintenance of proper intestinal function. Pro Performance L-Glutamin is tested and certified Banned Substance Free. GNC L-Glutamine powder is gluten and lactose-free. Supplementation with GNC L-Glutamine may help maintain the glutamine levels that have been depleted as a result of intense exercise. Glutamine, as an independent amino acids is involved in protein synthesis and plays a pivotal role in the body's nitrogen balance. It helps fuel immune system and maintenance of proper intestinal function.