Amino acids & related
Glutamine
Names you may see: L-glutamine fermented glutamine
The quick take
Glutamine is an amino acid used in proteins and by a variety of body tissues. It is also sold as a standalone sports supplement.
A closer look
What forms will I see on a label?
L-glutamine is commonly supplied as powder or capsules. Check the actual serving amount in blends.
Why people use it
Marketed for muscle recovery and maintaining muscle during demanding training.
These are common goals and marketing uses. The evidence section below explains what research supports.
What does the evidence tell us?
Despite its physiological importance, supplemental glutamine has not consistently improved strength, muscle gain or exercise performance in healthy, well-nourished athletes.
What should I know before using it?
Follow the directions and cautions on the specific product. Ask a pharmacist about suitability if you take medication or have a medical condition.
Sources & further reading
NIH Office of Dietary Supplements ↗
Content reviewed: September 30, 2026
General educational information. Follow the product label and seek individual advice when needed.