What is L-Alanyl-L-Glutamine? (also known as Glutamine Dipeptide)
L-alanyl-L-glutamine as the name suggests is a dipeptide made up of the amino acids, alanine and glutamine. L-alanyl-l-glutamine was developed to overcome the issues of stability and solubility associated with free l-glutamine1. When placed in solution, l-glutamine partially degrades to ammonia and pyroglutamic acid2; both toxic substances to the body. The extent of degradation increases with increasing temperature and length of time in solution. By contrast l-alanyl-l-glutamine is very stable in solution and under high temperatures; it is also stable at low pH.
Where Does L-Alanyl-L-Glutamine Come From?
L-alanyl-l-glutamine does not occur naturally in nature or food. Thus it must be made synthetically.
The benefits of l-alanyl-l-glutamine are generally the same as those ascribed to glutamine. These centre on glutamine’s importance for proper immune function as well as gut health. However, there are three specific studies where glutamine has been used by various types of athletes to improve measures of performance and/or hydration. Taken together, these studies suggest that use of l-alanyl-l-glutamine before, during and after exercise can help to prevent dehydration, reduce fatigue and improve sport-specific performance3-5. In addition to these human studies, three studies have been performed in rats to try to determine various performance enhancing effects of l-alanyl-l-glutamine. Together these studies have shown that in exercising rats, l-alanyl-l-glutamine can increase endogenous stores of glutathione, increase muscle glutamine content and reduce markers of exercise inflammation relative to glutamine alone6-8. Aside from its recent use in sports nutrition products, l-alanyl-l-glutamine is used extensively in clinical settings with patients in various catabolic states, such as burn victims, post surgery, trauma and sepsis1. Studies have shown that when added to the normal diet given to intensive care unit patients; l-alanyl-l-glutamine leads to a reduction in infectious complications9.
L-Alanyl-L-Glutamine Negative Side Effects
There are no known negative side effects from l-alanyl-l-glutamine.
L-Alanyl-L-Glutamine Recommended Dosages & Timing
As yet, there is no defined optimal does for l-alanyl-l-glutamine. The studies in humans that have examined the effects of l-alanyl-l-glutamine on performance and hydration used dosages ranging from 1 to 2.5g3, 5 or between 0.05g/kg to 0.2g/kg bodyweight4. Studies in clinical populations have used up to 20g10, but this dose will be inappropriate for most due to prohibitive cost. Given l-alanyl-l-glutamine is used mostly as a superior substitute for l-glutamine, the same general dosage guidelines used for l-glutamine can also be used for l-alanyl-l-glutamine. In human studies, l-alanlyl-l-glutamine has been given before, during and after exercise3-5.
Despite the promising theory, research and history of use in the clinical/hospital setting, l-alanyl-l-glutamine is yet to feature in an extensive range of sports nutrition supplements. Nonetheless it does feature in several products, as shown on the right-hand side of this page. A Japanese firm by the name of Kyowa owns the only patented form of oral l-alanyl-l-glutamine, which carries the name, SustamineTM.
Because of its importance in immunity and recovery, l-alanyl-l-glutamine is best stacked with recovery formulas and protein powders designed to augment heavy training loads.
1. Furst P. New developments in glutamine delivery. Journal of Nutrition. 2001;131(Suppl):2562S-2568S.
2. Gandini C, et al. HPLC determination of pyroglutamic acid as a degradation product in parenteral amino acid formulations. Chromatographia. 1993;36(1):75-78.
3. Hoffman JR, et al. L-alanyl-L-glutamine ingestion maintains performance during a competitive basketball game. Journal of the International Society of Sports Nutrition. 2012;9(1):4.
4. Hoffman JR, et al. Examination of the efficacy of acute L-alanyl-L-glutamine ingestion during hydration stress in endurance exercise. Journal of the International Society of Sports Nutrition. 2010;7:8-20.
5. Favano A, et al. Peptide glutamine supplementation for tolerance of intermittent exercise in soccer players. Clinics (Sao Paulo). 2008;63(1):27-32.
6. Rogero MM, et al. Effect of alanyl-glutamine supplementation on plasma and tissue glutamine concentrations in rats submitted to exhaustive exercise. Nutrition. 2006;22(5):564-571.
7. Cruzat VF, Tirapegui J. Effects of oral supplementation with glutamine and alanyl-glutamine on glutamine, glutamate, and glutathione status in trained rats and subjected to long-duration exercise. Nutrition. 2009;25(4):428-35.
8. Cruzat VF, Rogero MM, Tirapegui J. Effects of supplementation with free glutamine and the dipeptide alanyl-glutamine on parameters of muscle damage and inflammation in rats submitted to prolonged exercise. Cell Biochem Funct. 2010;28(1):24-30.
9. Dechelotte P, et al. L-alanyl-L-glutamine dipeptide–supplemented total parenteral nutrition reduces infectious complications and glucose intolerance in critically ill patients: The French controlled, randomized, double-blind, multicenter study. Critical Care Medicine. 2006;34(3):598-604.
10. Melis GC, et al. The feeding route (enteral or parenteral) affects the plasma response of the dipetide Ala-Gln and the amino acids glutamine, citrulline and arginine, with the administration of Ala-Gln in preoperative patients. British Journal of Nutrition. 2005;94:19–26.