Glutamine is the most abundant amino acid in muscle tissue. It is involved in key metabolic processes, such as ammonia removal (*1), and is crucial for the maintenance of the immune system (*2). We offer high-quality glutamine formulas available in both tablet and powder form.
What is glutamine?
As the most naturally abundant amino acid in the body, glutamine has several important physiological functions. Although glutamine can be found in the liver, lungs, brain and blood plasma, most of it is stored in muscle cells.
Glutamine is a precursor of both arginine and citrulline, two important amino acids for vasodilatation (*3), (*4). It is also a precursor of the neurotransmitter GABA and the antioxidant glutathione.
Glutamine is very interesting from a physiological point of view. It helps remove exercise-generated ammonia (*5), a harmful toxin in the body, and plays a fundamental role in fueling the immune system (*6).
Other glutamine benefits
Glutamine is the main energy source for some of the immune system's cells, including lymphocytes and macrophages (*7), (*8), (*9). Research suggests that these cells rely on glutamine in a greater amount than they rely on glucose, hence the importance of glutamine for a strong immune system.
Strenuous exercise can lower blood glutamine drastically (*10), therefore exposing the body to the harmful free radicals. Research has shown that endurance athletes are more vulnerable to infections, due to low glutamine levels after stressful workouts (*11).
The good news,however, is that this dramatic drop in glutamine levels can be counteracted by supplementing with this amino acid. Glutamine supplementation can help reduce the risk of infections and lower inflammation levels (*12).
Glutamine is also known for its hydration effect on muscle cells. Research shows glutamine pulls water into the cells thus contributing to glycogen synthesis (*13).
Glutamine dosage will depend on how intense your workouts are. The more demanding your workouts are the higher the dose should be. Experienced athletes may need a high-dose of glutamine (10 to 20 g) whereas beginners would do just fine with a low-dose (5g).
When to take Glutamine
The best way to benefit from glutamine supplementation is to take between 5 to 15 grams after working out. The dosage will depend on how intense your workout is. Remember that on rest days you should still consume glutamine.
Does Glutamine have side effects?
Research has demonstrated that short-term glutamine supplementation is safe. One scientific study evaluated the safety of consuming large doses of glutamine over a period of 5 days.Volunteers were given from 0,3 to 0,6 g / kg of glutamine every day. This would be similar to a 80 kg person consuming between 22-45 g of glutamine.
There was no evidence of toxicity recorded in the subjects that consumed the higher doses. Furthermore,glutamine supplementation combined with a high-calorie and a high-protein diet increased body's ability to retain nitrogen, an important factor for stimulating muscle growth (*14).
In another scientific study, athletes taking 28 g of glutamine every day for a period of 14 days didn't report any negative side effect. This seems to indicate that glutamine supplementation on the short-term is completely safe (*15).
However, it's not recommended to consume high-doses of glutamine (over 40 g / day) for an undetermined period of time, as glutamine competes for transporters with other amino acids and this could lead to a decrease in the absorption of those other important amino acids (*16).