Research protocols for sports use most commonly use approximately 0.1-0.3 g per kilogram of body weight per day, which for an average adult amounts to around 5-10 g daily (Gleeson, 2008). At the full recommended dose (6 capsules, 3 x 2 throughout the day), this product provides 4500 mg (4.5 g), which is close to the lower end of this range, though still slightly below it. If you want to reach the upper part of the research-used range, you would need to adjust the dose upward in consultation with a professional, without exceeding the recommended daily dose on the label without consultation.

Such warnings are a common precautionary practice by manufacturers of sports supplements containing amino acids, as clinical data on the long-term safety and appropriate dosages of glutamine in minors have not been sufficiently researched – most studies on dosing and safety have been conducted on adults (Holeček, 2013; Garlick, 2001). In children and adolescents, physical nutrient needs and metabolic processes also differ, so in the absence of adequate data, the manufacturer reasonably limits recommended use to adults. If you are considering supplementation for a minor, first consult a pediatrician or sports physician.

The effect depends solely on the total amount of pure L-glutamine consumed per day, not on the form in which it is taken – capsules and powder deliver the same active ingredient, and glutamine itself does not have different 'compound forms' as, for example, some minerals do. The difference is therefore practical: to reach the same daily dose with capsules as with a single scoop of powder, you need to take several capsules at once (for this product, for example, 6 capsules for 4.5 g), which some may find less convenient, but this does not mean lower biological effectiveness of the ingredient itself.

In highly loaded athletes such as combat sports athletes, there are newer, though still smaller, studies suggesting possible benefits of glutamine for mucosal immunity and hormonal status after intense training (Melo et al., 2024). This is consistent with the theory that intense and prolonged exercise can temporarily lower plasma glutamine concentration, thereby increasing susceptibility to upper respiratory infections in the post-exercise period. In the general, less heavily loaded recreational population, such benefits have not been as consistently confirmed (Gleeson, 2008), so the expected benefit is likely greater for you than for the average fitness supplement user – but glutamine should remain a supplement to proper nutrition and rest, not a replacement for them.