What Is the Difference Between L-Lysine & L-Glutamine?

Lysine and glutamine are two of the 20 amino acids your body needs in order to make the proteins it uses to build and repair cellular tissue, support normal growth and development and break down food. Without enough of either amino acid, you may develop anemia, have trouble recovering from illnesses or experience reproductive and digestive problems, nausea, delayed growth, dizziness and fatigue. L-lysine and L-glutamine are the naturally occurring forms of each amino acid.

Type of Amino Acid

Lysine is one of the nine essential amino acids. Essential amino acids are those your body cannot make and that you must obtain either from food or dietary supplements. By contrast, glutamine is considered a conditional amino acid. These are amino acids that may become essential if you are sick or injured, undergo surgery or exercise heavily. In these instances, you'll need to consume glutamine to get enough.

Function in the Body

Your body needs adequate lysine to help synthesize the collagen that produces and maintains bones and connective tissue. Lysine is also required for the production of carnitine, a compound that takes part in the breakdown of dietary fats and the regulation of blood cholesterol levels. Glutamine supports the health and function of the nervous, digestive and immune systems and helps you eliminate excess ammonia. Your body can convert glutamine to glucose if your cells need energy.

Possible Health Benefits

Supplemental glutamine may help athletes recover after exercise, though more research is needed. As part of a high-protein diet, glutamine and lysine support new protein synthesis, which is essential for repairing microscopic muscle tears that occur during exercise. Lysine also helps your body process calcium properly, improving calcium absorption from your diet, notes the University of Maryland Medical Center. Because calcium is essential to bone health, lysine might help keep your skeleton strong, but more research is needed to know for sure.

Best Food Sources

Red meat, fish, poultry, soy, eggs, nuts and dairy products are good sources of lysine. Raw soybeans contain 5 grams of lysine per cup, while a fillet of beef rib-eye steak supplies 4.1 grams, and a 3-ounce serving of roasted turkey breast meat has about 2.6 grams. Like lysine, glutamine is found in high concentrations in most protein-rich foods. A study published in the "European Journal of Clinical Nutrition" in 2009 reported that beef contains 1.2 grams of glutamine in every 3.5-ounce serving and that an equivalent serving of tofu has 0.6 gram.