ʟ‑Glutamine is the most common naturally occurring amino acid found in muscle tissue, populating in excess of 50% of skeletal muscle tissue. Glutamine is not an essential amino acid, as it is a derivative of glutamic acid, which can be synthesized from the amino acids arginine, ornithine, and proline; however, the body can easily exhaust its supply. This makes ʟ‑glutamine conditionally essential in certain disease states to support the gut-barrier and immune function as well as overall protein use. ʟ‑Glutamine is a precious precursor for glutathione synthesis, which serves as the body’s most powerful antioxidant compound.

Glutamine also decreases catabolism (the breakdown of muscle tissue), the process where glutamine leaves the muscle, causing muscle cells to become dehydrated.

ʟ‑Glutamine supplementation ensures that sufficient levels of glutamine are maintained within cells, minimizing dehydration and catabolism. Supplementation prevents glutamine depletion in muscle cells after workouts. Studies have shown that supplementing with ʟ‑glutamine is effective in the replacement of these declining levels.