Glutamine

Does it work?

• -Mostly no. Glutamine is one of the most abundant amino acids in your body, and you make plenty of it on your own — plus you get more from any protein-rich diet. In healthy lifters, controlled trials show it does nothing for strength, lean mass, or muscle breakdown beyond placebo, and meta-analysis finds no effect on body composition. It earned a recovery reputation it doesn't live up to.

The catch

• -Your body makes glutamine, and a normal protein intake (especially whey, meat, dairy) already delivers grams of it daily — supplementing tops off a tank that isn't empty.
• -A resistance-training RCT found no difference from placebo in strength, lean mass, or muscle-protein breakdown. A meta-analysis in athletes found no effect on body composition.
• -The 'gut health' and 'immune' claims come from critically ill or overtrained populations — they don't transfer to a healthy lifter eating enough food.

Better option

• -Hit your daily protein target (~1.6 g/kg) — it already supplies all the glutamine a healthy lifter needs, and creatine actually moves recovery and muscle.

Safety

• -Generally well tolerated and considered safe at typical doses (5-10 g/day).
• -No meaningful upside for healthy, well-fed lifters — the main downside is wasted money.
• -If you have liver or kidney disease, clear any amino-acid supplement with your doctor first.

Key research

• ISSN exercise & sports nutrition review update: research & recommendationsJ Int Soc Sports Nutr · 2018 · Position stand
• The effect of glutamine supplementation on athletic performance, body composition, and immune function: A systematic review and a meta-analysis of clinical trialsClinical Nutrition · 2019 · Meta-analysis
• Glutamine: Metabolism and Immune Function, Supplementation and Clinical TranslationNutrients · 2018 · Review
• A systematic review and meta-analysis of clinical trials on the effects of glutamine supplementation on gut permeability in adultsAmino Acids · 2024 · Meta-analysis
• The Influence of Oral L-Glutamine Supplementation on Muscle Strength Recovery and Soreness Following Unilateral Knee Extension Eccentric ExerciseInt J Sport Nutr Exerc Metab · 2015 · RCT

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