The extremely popular amino acid L-Glutamine can be found in protein powders, beans, meats, fish, poultry, dairy products, and of course, L-Glutamine supplements from Bodybuilding.com.

2. What does it do and what scientific studies give evidence to support this?

  • Fuel Your Performance!*
  • Promote Glycogen Resynthesis!*
  • Support Protein Metabolism!*
  • The Athlete's Amino Acid!*

Glutamine is highly in demand throughout the body. It is used in the gut and immune system extensively to maintain optimal performance.* 60% of free-form amino acids floating in skeletal muscles is L-glutamine. L-glutamine plays a very important role in protein metabolism, and it appears to be a very important nutrient for athletes.* When supplemented, it may help athletes reduce the amount of muscle breakdown that occurs because other tissues that need glutamine will not rob the glutamine stored in the muscle cells.*

Research suggests that after intensely working out, glutamine levels in the body are reduced by as much as 50%.* Since the body relies on glutamine as cellular fuel for the immune system, scientific studies suggest that glutamine supplementation can minimize the breakdown of muscle tissue and improve protein metabolism.* Glutamine's cell-volumizing effects have also been supported by several studies.* No conclusive studies have been done to evaluate the effects of L-glutamine supplementation on weight-training adults; however, a recent study suggests a meaningful increase in growth-hormone levels when as little as 2 grams of free-form L-glutamine supplement was consumed!*

3. Who needs it and what are some symptoms of deficiency?

Athletes can particularly gain from the intake of glutamine. Since athletes use a lot of their glutamine when working out, the immune system relies heavily on this amino acid.*

Catabolism or muscle break down may occur if the body robs muscles of glutamine for use elsewhere.* Glutamine supplementation seems to play a pivotal role in the maintenance of muscle mass when training hard.*

4. How much should be taken? Are there any side effects?

Reports of an upset stomach are associated with ingesting large quantities of glutamine; using smaller doses is recommended if this occurs. Always consult the manufacturer's labeling for instructions on proper supplement dosage.

Note: Glutamine peptides are different than regular L-glutamine.