ATP Science L-Glutamine — The Most Abundant Amino Acid in the Body, in Pure Form

Glutamine is the most abundant amino acid in human blood and skeletal muscle tissue. Under normal conditions your body produces enough — but intense exercise, catabolic stress and calorie restriction push demand well beyond what the body can synthesise, making supplementation conditionally essential. ATP Science L-Glutamine is 100% pure L-Glutamine, HPLC-verified for purity and potency, tested for allergens, pesticides and heavy metals, vegan, gluten-free and GMO-free. 5g per serve, 500g (100 serves) or 1kg (200 serves), in stock at Payless Supplements.

Dosage & Timing

Mix approximately 5g (one heaped teaspoon) with 200–300ml of water or your post-workout shake. For standard recovery support, take once daily before or after training. For high-load training blocks, nutritionists recommend 5g up to three times daily — morning, pre-training and post-training. Stimulant-free and calorie-free; timing is flexible.

Why Glutamine Becomes Essential Under Training Stress

Glutamine is classified as conditionally essential — your body can make it under normal circumstances, but its demand in catabolic conditions (heavy training, calorie restriction, illness or injury) consistently outstrips synthesis capacity. When this happens, plasma glutamine levels fall, and the cells that depend on glutamine as their primary fuel source — intestinal enterocytes, immune cells and liver hepatocytes — begin to compete for limited supply. The result is slower recovery, compromised gut integrity and suppressed immune function, all of which are common complaints among athletes in hard training blocks.

Key Points

• Muscle recovery — glutamine provides nitrogen for protein synthesis, supports tissue repair and helps reduce muscle soreness in the days following intense training.
• Immune support — immune cells use glutamine as their primary energy substrate. Supplementing during heavy training periods helps maintain immune function when plasma levels are under pressure.
• Gut health and integrity — intestinal enterocytes (the cells lining the gut wall) depend on glutamine as their main fuel source. Adequate glutamine supports intestinal barrier integrity, which matters for nutrient absorption and reducing gut permeability under training stress.
• Anti-catabolism — glutamine helps protect muscle tissue during periods of high training load or calorie restriction by supporting nitrogen balance.
• Endurance support — during prolonged exercise, glutamine participates in gluconeogenesis (glucose production from non-carbohydrate sources), helping to maintain blood glucose when carbohydrate stores are depleted.

ATP Science Quality Standards

ATP Science sources glutamine from a manufacturer that permits audits of their facility and provides full traceability. Every batch is:

• HPLC verified — guaranteeing the material is fully efficacious L-Glutamine with no contaminants or adulteration
• Allergen, pesticide and heavy metal tested — compliance testing beyond standard amino acid specifications
• Microbial tested — produced and tested to pharmaceutical quality standards
• Vegan, gluten-free, GMO-free — no hidden ingredients, no compromise on dietary requirements

Which Size?

• 500g / 100 serves — approximately three months at the standard 5g once daily dose. A good starting size.
• 1kg / 200 serves — six months at 5g daily, or three months at 5g twice daily during heavy training blocks. Better value per gram for committed users.

How to Stack It

L-Glutamine is flavorless and mixes invisibly into any other supplement. ATP Science recommend stacking it with their NOWAY!® Collagen Protein post-training for a comprehensive recovery drink — the collagen provides structural protein for connective tissue and joints while glutamine covers the recovery and immune support angle. It also stacks cleanly with creatine, BCAAs or any protein powder.