L-glutamine

Also known as glutamine, l glutamine.

Last reviewed October 9, 2026 · Jump to references

What is L-glutamine?

In plain words

L-glutamine is an amino acid, a building block of protein that your body makes and also gets from food. Your body uses it to build proteins and fuel cells, including those in the gut and immune system. Researchers study it for gut health, recovery from illness, and sickle cell disease. Evidence depends on the condition, and approval of a prescription product does not mean supplements have proven benefits for general health.

Technical definition

L-glutamine is a proteinogenic α-amino acid with an uncharged amide side chain; it is synthesized in the body and is conditionally essential when metabolic demand exceeds endogenous production. Rather than acting through a single receptor, it serves as a nitrogen donor and metabolic substrate, with glutaminase converting it to glutamate for subsequent biosynthetic and energy-producing pathways. In the United States, it is marketed as a dietary supplement, and a prescription L-glutamine product is FDA-approved to reduce acute complications of sickle cell disease.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.