The Claim

L-glutamine supplementation at 0.3 g/kg body weight per day for three weeks in combat-sport athletes increases salivary nitric oxide concentration.

Source: Supplementation of L-glutamine enhanced mucosal immunity and improved hormonal status of combat-sport athletes

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
54score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

Taking L-glutamine at a dose of 0.3 grams per kilogram of body weight daily for three weeks increases the concentration of nitric oxide in saliva among combat-sport athletes.

See the scientific wording

L-glutamine supplementation at 0.3 g/kg body weight per day for three weeks in combat-sport athletes increases salivary nitric oxide (NO) concentration, likely due to its role as a precursor to arginine, which supports mucosal immune defense against respiratory pathogens.

Why this might work

L-glutamine is absorbed from the gut and converted into arginine in immune and mucosal cells. Arginine is used by enzymes to produce nitric oxide, which builds up in saliva and kills bacteria in the mouth and throat. This process strengthens the body’s first line of defense against germs that cause respiratory infections.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Supplementation of L-glutamine enhanced mucosal immunity and improved hormonal status of combat-sport athletes

    This study found that athletes who took L-glutamine powder for three weeks had more nitric oxide in their saliva, which helps protect their airways from germs. So yes, L-glutamine seems to help the body make more of this protective molecule.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.