Not worth it for recovery, muscle gain and health.
The label shows how strong the evidence is, not how big the effect is. Tap a claim to see its papers.
In plain words
For a lifter, nothing measurable. Over 6 weeks of training, lean mass rose 2% with glutamine and 1.7% with placebo, not a significant difference; 0.3 g/kg before lifting added no reps on leg press or bench press. One 16-person trial found soreness 2.6 vs 3.9 (glutamine vs placebo) 48 hours after eccentric exercise.[1][4][8]
One 16-person crossover trial found lower soreness ratings and faster recovery of fast-speed knee strength after eccentric exercise; no meta-analysis of recovery outcomes exists.[1][2][3]
The only direct recovery trial found is small, short and limited to one leg exercise; reviews of glutamine in healthy athletes find little support for performance benefits. A single small positive trial is Grade C.
Each plate is one paper. Taller = stronger study design, wider = more studies pooled. Tap one.
Glutamine generally had no effect on athletes' immune function, aerobic performance or body composition, though it was associated with greater weight reduction.
Proposed reasons to take glutamine (immune support, glycogen, anti-catabolic effects) have little support from well-controlled studies in healthy, well-nourished people.
Glutamine for 72 hours led to faster recovery of peak torque and less soreness after eccentric exercise; the strength effect may be larger in men.
No added gain: in a 6-week training RCT, lean mass rose 2% with glutamine and 1.7% with placebo, not a significant difference, and a meta-analysis of 25 trials found no effect on body composition.[2][3][4]
A controlled RCT in young lifters and a meta-analysis of athlete trials both find no benefit for muscle or strength. Good trials finding no effect is Grade D.
Each plate is one paper. Taller = stronger study design, wider = more studies pooled. Tap one.
Glutamine generally had no effect on athletes' immune function, aerobic performance or body composition, though it was associated with greater weight reduction.
Proposed reasons to take glutamine (immune support, glycogen, anti-catabolic effects) have little support from well-controlled studies in healthy, well-nourished people.
During 6 weeks of resistance training, glutamine had no significant effect on strength, lean mass or muscle protein breakdown compared with placebo.
No benefit in healthy athletes: a meta-analysis found glutamine generally had no effect on athletes' immune function, and reviews conclude it does not improve immune surveillance in healthy, well-fed people.[2][3][5]
The immune theory rests on a fall in blood glutamine after hard exercise, but controlled studies in healthy, well-nourished people do not show immune benefits. Benefits on infection are limited to critically ill or surgical patients. Good null evidence in healthy people is Grade D.
Each plate is one paper. Taller = stronger study design, wider = more studies pooled. Tap one.
Glutamine generally had no effect on athletes' immune function, aerobic performance or body composition, though it was associated with greater weight reduction.
Glutamine is the body's most abundant amino acid and fuels immune cells; it can become essential in critical illness, but in healthy people on a balanced diet supplements do not improve immune surveillance.
Proposed reasons to take glutamine (immune support, glycogen, anti-catabolic effects) have little support from well-controlled studies in healthy, well-nourished people.
Glutamine is the most abundant amino acid in the body, making up 50-60% of the free amino acids in muscle. The body makes an estimated 40-80 g a day, and a typical diet adds about 6.85 g a day from protein foods, so it is rarely in short supply in healthy people.
Hard exercise can lower blood glutamine, and immune and gut cells use glutamine as fuel, so the marketing claim is that supplements protect immunity and stop muscle breakdown. The theory breaks down early: a high proportion of swallowed glutamine is kept by gut cells and only small amounts reach the blood. Adding glutamine to a post-workout amino acid and carbohydrate drink did not raise muscle protein synthesis or glycogen refilling. Its best-supported effects are local to the gut and in critical illness.[3][5][6][7]
Reviewed 03 Oct 2026 · every PubMed ID checked against PubMed
0.3 g/kg/day (recovery trial) to 0.9 g/kg lean mass/day (training trial)
Lowered a gut-permeability marker in the heat at all three doses, most clearly at the highest.[11]
No extra repetitions on leg press or bench press.[8]
Less soreness and faster strength recovery after eccentric exercise in one small trial.[1]
No added strength or lean mass.[4]
No reported harm in healthy people.[3]
Absorbed more efficiently and raised glutamine levels more than free glutamine, mainly in animal studies; no evidence it improves lifting results.[6]
Adding glutamine to a post-exercise drink gave no extra muscle protein synthesis or glycogen resynthesis.[7]
| Food | Amount |
|---|---|
| Protein foods (meat, dairy, eggs, soy, grains) | About 6.85 g/day in total from a typical diet[5] |
Glutamine delays fatigue so you can train harder.
It improved some fatigue markers such as ammonia build-up, but across 55 studies it did not improve physical performance.[6]
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