Glutamine Side Effects and Warnings

Safety Issues

As a naturally occurring amino acid, glutamine is thought to be a safe supplement when taken at recommended dosages. There is strong evidence that glutamine is safe at levels up to 14 g per day, although higher dosages have been tested without apparent adverse effects. ¹ Nevertheless, those who are hypersensitive to monosodium glutamate (MSG) should use glutamine with caution, as the body metabolizes glutamine into glutamate. Also, because many anti-epilepsy drugs work by blocking glutamate stimulation in the brain, high dosages of glutamine might conceivably overwhelm these drugs and pose a risk to people with epilepsy . Finally, in one case report, high doses of the supplement L-glutamine (more than 2 g per day) may have triggered episodes of mania in two people not previously known to have bipolar disorder . ² Maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been determined.

Interactions You Should Know About

If you are taking:

• Antiseizure medications, including carbamazepine , phenobarbital , phenytoin (Dilantin) , primidone (Mysoline) , and valproic acid (Depakene) : Use glutamine only under medical supervision.
• Nelfinavir or other protease inhibitors for HIV, or cancer chemotherapy drugs: Use of glutamine may reduce intestinal side effects.