You should make sure you are aware of L-glutamine safety warnings and precautions before starting the supplement, especially if you have any existing medical conditions. L-glutamine supplementation may worsen hepatic encephalopathy, a brain condition due to high ammonia levels caused by liver disease. You may also not be able to take L-glutamine safely if you have seizures or epilepsy, bipolar disorder, or severe liver disease.
L-glutamine (also known as glutamine) is a dietary supplement used to treat a variety of conditions. You may not be able to take L-glutamine safely if you:
- Have severe liver disease, such as liver failure
- Have bipolar disorder (also known as manic depression)
- Have seizures or epilepsy
- Are allergic or sensitive to MSG (monosodium glutamate)
- Have any other allergies, including allergies to food, dyes, or preservatives
- Are pregnant or thinking of becoming pregnant
- Are breastfeeding.
You should also be sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Warnings and precautions to be aware of concerning the safety of L-glutamine include the following:
- In theory, L-glutamine supplementation may worsen hepatic encephalopathy (a brain condition due to high ammonia levels caused by liver disease) because the body breaks L-glutamine down into ammonia. If you have liver problems (especially severe liver disease), do not take L-glutamine supplements without your healthcare provider's approval and supervision.
- In theory, L-glutamine may increase the risk of seizures, especially in people with a seizure disorder. If you have a history of seizures, check with your healthcare provider before taking L-glutamine.
- L-glutamine supplementation may increase the risk of mania in people with bipolar disorder. If you have bipolar disorder, it is probably a good idea to avoid L-glutamine supplementation.
- Because L-glutamine is chemically related to glutamate (and because the body breaks down L-glutamine into glutamate), some people who are allergic or sensitive to MSG (monosodium glutamate) may also be allergic to glutamate.
- L-glutamine may potentially interact with a few medications (see Drug Interactions With L-Glutamine).
- If you decide to use supplements (such as L-glutamine), what you see on the label may not reflect what is in the bottle. For example, some herbal supplements have been found to be contaminated with heavy metals or prescription drugs, and some have been found to have much more or much less of the featured ingredient than their label states.
Therefore, make sure the manufacturer of your L-glutamine product is a trusted and reputable manufacturer. It is a good sign if a manufacturer abides by the rules of Good Manufacturing Practices (GMP) for drugs. It is also a good sign if a product has the United States Pharmacopoeia (USP) seal, which means that the product has been independently tested and shown to contain the correct ingredients in the amounts listed on the label. Your pharmacist is a good resource for information about which manufacturers are most reputable.
- It is not known whether L-glutamine supplements are safe for pregnant or breastfeeding women (see Glutamine and Pregnancy and Glutamine and Breastfeeding).