L-Glutamine is the most abundant free amino acid in the body, playing a central role in immune cell function, intestinal barrier integrity, and nitrogen transport between tissues. Research suggests that glutamine levels can become depleted during periods of intense physical stress, prolonged exercise, or illness, which has led to significant interest in supplementation for recovery and immune support. Studies indicate that L-glutamine may help maintain gut lining health by supporting the cells that line the intestinal wall, and some evidence points to reduced muscle soreness and improved recovery when used around strenuous training. Available widely as both a powder and in capsule form, it remains one of the more extensively studied amino acids in sports nutrition and gastroenterological research, though individual responses can vary.
Compare this supplementResearch suggests that L-glutamine plays a meaningful role in supporting immune function across several contexts, wit...
View studies →Research suggests that L-glutamine may play a modest role in supporting muscle glutamine and protein levels during re...
View studies →Research suggests that L-glutamine plays a meaningful role in supporting intestinal barrier function, gut immune regu...
View studies →The studies provided do not contain research on L-Glutamine or muscle recovery. The linked literature covers topics i...
View studies →These are commonly referenced dosage ranges for this supplement. They are not medical recommendations. Always consult a healthcare provider before supplementing.
| Form | Dose range | Frequency | Studied for | Source |
|---|---|---|---|---|
| Capsule | 5 g | Twice daily | General gut health and immune function maintenance | Common supplementation protocol seen in multiple RCTs |
| Powder | 0.5 g | Daily | Critical illness and surgical recovery, dosed per kg body weight | Based on clinical trials in ICU and post-surgical patients |
| Powder | 20–30 g | Daily | Exercise recovery and muscle recovery in high-intensity athletes | Used in RCTs studying post-exercise muscle soreness and glycogen replenishment |
| Powder | 5–10 g | Daily | Gut health and intestinal permeability support | Common in clinical trials examining leaky gut and mucosal integrity |
| Powder | 0.1–0.3 g | Daily | Immune function support, dosed per kg body weight | Per-kg dosing used in clinical trials on immune markers and glutamine depletion in athletes |