Summary
What is L-glutamine?
Glutamine (L-glutamine) is an amino acid that your body produces. It is involved in cellular energy production and plays a role in maintaining muscle cells, the immune system, and the digestive tract.(See details in What It Is).
What are the health benefits of L-glutamine?
Although you do not need to get glutamine from your diet or supplement with it, there is some evidence that large doses (several grams) may reduce infections after over-training, reduce symptoms of irritable bowel syndrome after infections, and reduce mouth irritation due to chemotherapy (see details in What It Does).
How much L-glutamine is taken?
Typical dosage of L-glutamine is 4 to 6 grams (4,000 to 6,000 mg) taken one or more times daily (see details in ConsumerTips).
Which L-glutamine supplement is best?
Nearly all L-glutamine supplements contain essentially the same L-glutamine in its free form. However, the cost can range from just 4 cents to 56 cents per gram. Among products Approved for quality in ConsumerLab ’s tests of popular L-glutamine supplements (see What CL Found), ConsumerLab selected a Top Pick for L-glutamine powder and a Top Pick for L-glutamine capsules, each of which represent exceptional value relative to other products.
What to look for on L-glutamine labels?
L-glutamine is sold almost exclusively in the free form and is produced by fermentation, so it is not necessary to pay more for products claiming to be “free form.”
L-glutamine safety and side effects:
Glutamine is believed to be generally safe but can cause gastrointestinal side effects at daily doses of 10 grams or more. Lower doses may cause symptoms in people hypersensitive to MSG (monosodium glutamate). Dry mouth, headache, and dizziness may occur with daily doses of 30 grams or more. There is concern glutamine may interfere with anti-epilepsy drugs and may trigger mania in people with bipolar disorder. (See details in Concerns and Cautions).
