Jarrow Formulas L-Glutamine 750mg, 120 Capsules

Although a nonessential amino acid, L-glutamine has become the focus of extensive scientific interest because of its important physiological role. Since the 1980s, many researchers have come to regard glutamine as “conditionally essential. ” Conditionally essential nutrients are those which the body can produce in quantities sufficient to maintain health under normal circumstances, but for which the body’s needs outstrip synthesis under various conditions. In the case of glutamine, food restriction and other forms of physical and/or mental stress can cause the body to require more glutamine than will be available without supplementation. Under non-stressful conditions, adequate glutamine is synthesized primarily from glutamic acid, valine, and isoleucine. However, stress can decrease glutamine levels in the blood by as much as 30% and the levels in the muscles by as much as 50%.

Glutamine is important for muscle regeneration because it is an important precursor of nucleic acids, nucleotides, amino sugars, and proteins particularly by virtue of its ability to transport nitrogen between tissues. For this reason, glutamine is often used for enhancing exercise performance and supporting post-workout recovery.* Glutamine is used not only in the muscles, but also in the metabolism of the immune system, the intestinal tract, the kidneys, gallbladder, pancreas, and liver. Among amino acids, glutamine uniquely serves as a preferred energy source for rapidly dividing cells, such as those of the intestinal wall and the lymphatic system. As a result, glutamine is often recommended to support immune and gastrointestinal health.*

Glutamine also acts as a regulator of the body’s acid-base balance – that is, it helps to maintain the proper pH of the system – through the buffering of ammonia. Glutamic acid reacts with ammonia when it is present in high concentrations producing glutamine. Glutamine also readily passes across the blood-brain barrier, where it serves as a precursor for both the stimulating neurotransmitter, glutamic acid, and the calming agent, gamma-aminobutyric acid (GABA). Glutamic acid does not cross the blood/-brain barrier. This could be why glutamine has been used to support and stabilize mood, especially by dieters.*

L-Glutamine - the most abundant amino acid in the human body - is involved in many metabolic processes, including the synthesis and protection of muscle tissue, the production of glycogen, and immune support during periods of immune and muscular stress.* L-Glutamine is also a major source of fuel for enterocytes (intestinal cells) and hence supports the integrity of the intestinal lining.*

A series of dose-response studies was conducted to evaluate the clinical safety, pharmacokinetics, and metabolic effects of L-glutamine administered to humans. Initial studies in normal individuals evaluated the short-term response to oral loads of glutamine at doses of 0, 0.1, and 0.3 g/kg. A dose-related increase in blood glutamine occurred after oral loading and elevation of amino acids known to be end products of glutamine metabolism occurred (including alanine, citrulline, and arginine). No evidence of clinical toxicity or generation of toxic metabolites (ammonia and glutamate) was observed.* Glutamine has been shown to be safe in oral doses up to 40 grams per day. Significant side effects have not been reported in clinical studies. However, mania has been reported in some individuals with bipolar disorder so should be avoided if bipolar disorder has been diagnosed or is suspected.