Glutamine: What It Is, Benefits & Side Effects (2024)

What is glutamine?

Glutamine is the most abundant of 20 different amino acids in your body. An amino acid is a building block of protein. Proteins help with many jobs. For example, proteins can help repair body tissues, keep your digestive system working and help your immune system fight germs. As a protein building block, glutamine plays a role in these functions (and others), too.

Glutamine is a conditional nonessential amino acid. “Nonessential” means you get glutamine from foods you eat, but your body makes it, too. (In contrast, you have to get “essential” amino acids from foods because your body can’t make them.) Glutamine is “conditional” because, although your body usually makes enough of it, there may be moments when you need more than your body can make.

For example, your body uses more glutamine when you’re sick or injured. You may need to compensate by getting more glutamine from outside sources.

But most healthy adults have enough glutamine for good health and don’t need to up their intake.

What are the types of glutamine?

There are two types, L-glutamine and D-glutamine.

The most important one to know about when it comes to your body is L-glutamine. Often, when people mention glutamine, they mean L-glutamine.

What does glutamine do for your body?

Glutamine is an essential protein building block. It also helps make other amino acids and removes waste products, like ammonia, from your body. It plays a key role in chemical (metabolic) processes that provide your body with the energy it needs to work.

Glutamine supports your:

• Immune system: Glutamine is a crucial power source that fuels your immune system. Your white blood cells use glutamine to protect you from infections and keep you healthy. It plays a key role in processes that repair damaged tissue.
• Digestive system: Many of your white blood cells that use glutamine are in your intestines. Glutamine helps strengthen the cell barrier that prevents your intestines from becoming damaged. It helps maintain a healthy gut.

What are good food sources of glutamine?

Most of the glutamine you get from food comes from high-protein animal products. But you can get glutamine from other sources, too. Glutamine food sources include:

• Meat, including beef, pork and poultry.
• Dairy products, including eggs, milk, yogurt and cheese.
• Protein-rich non-animal products, including nuts and tofu.
• Vegetables, including corn and red cabbage.
• Grains, including rice and oats.

Most healthy people get enough glutamine from the food they eat without having to stress about meal planning. If your body needs extra glutamine, it makes it. This is what makes glutamine a nonessential amino acid.

What is glutamine used for?

The glutamine your body makes plays such an important role in maintaining your overall health that scientists are studying the potential benefits of taking glutamine supplements. For the most part, though, research shows that healthy people don’t need to take glutamine. Healthy bodies do a good job of making enough glutamine and getting it from a regular diet.

Some research suggests that taking glutamine can provide benefits in treating some conditions — although the evidence can be unclear. In most cases, more research is needed to understand any potential benefits of taking glutamine.

Sickle cell disease

The only FDA-approved use of glutamine is to reduce serious complications of sickle cell disease (SCD). SCD involves having oddly shaped red blood cells. These blood cells can get stuck in your blood vessels (veins, arteries and capillaries). L-glutamine (Endari®) can reduce symptoms, like pain, that can occur when this happens.

Burns or injuries

Trauma, including severe burns, surgery or other injuries, can lower your glutamine levels. Not having enough glutamine can prevent your immune system from working effectively.

Some research shows that people who are severely sick or injured may benefit from getting extra glutamine. Taking glutamine may prevent or reduce infections after surgery. It can prevent more extensive damage to your organs after a severe burn. Studies that prove glutamine’s benefits in these situations often involve providers adding glutamine to a person’s feeding tube in the hospital.

Still, it’s not clear if taking glutamine after an injury is effective for everyone. Much depends on the clinical scenario and the person.

Cancer

Healthy cells use glutamine as an energy source that helps them function and thrive. But cancer cells also use glutamine to thrive and spread. Cancer cells use more glutamine than healthy cells. They can use so much glutamine that healthy cells don’t have enough to carry out their functions. Related, people with cancer often have low glutamine levels.

Scientists are studying ways to disrupt the processes that allow cancer cells to thrive using glutamine, but this research is still in the early stages.

But glutamine isn’t only a power source for cancer cells. It provides benefits to people with cancer, too. Some studies show that glutamine supplements can help heal tissue after cancer treatments. For example, glutamine can reduce the pain associated with mucositis, or inflammation of your mouth and digestive tract after chemotherapy. Glutamine may also help relieve symptoms of neuropathy after chemotherapy.

More research is needed to understand how taking glutamine may reduce cancer treatment side effects.

HIV/AIDS

Some studies suggest that glutamine supplements can help people with HIV and AIDS. Glutamine may help people regain some of the weight they’ve lost since contracting HIV. Glutamine may also help antiviral medicines that treat HIV work better.

But research is ongoing, as it’s not clear if healthcare providers should recommend glutamine supplements.

Inflammatory bowel disease (IBD)

Glutamine’s role in maintaining the barrier that protects your intestines has led some researchers to study whether glutamine supplements help people with inflammatory bowel disease (IBD). IBD involves chronic (long-term) inflammation in your intestines. Studies have tested the theory, but none have proven that taking glutamine helps with IBD.

Athletic performance

Researchers have studied whether glutamine can boost athletic performance. A few studies have shown that glutamine may reduce muscle soreness after high-intensity exercise and decrease the risk of getting sick. Still, there’s not enough evidence to say that taking glutamine consistently provides these benefits. Research doesn’t support the idea that glutamine can help build muscle mass in athletes.

When should you take glutamine?

The short answer is: When your healthcare provider recommends it. Your provider may prescribe glutamine if you have sickle cell disease. They may recommend supplementing with glutamine or eating more foods with glutamine if your immune system needs a boost.

Your provider should give the OK on any supplements you’re taking to ensure they’re safe based on your health. It’s important to inform your provider of any supplements you’re taking.

What are the benefits of taking glutamine?

Taking glutamine can reduce the risk of sickle cell disease complications. It can potentially prevent infections and reduce tissue damage following trauma (an injury or burn) or cancer treatment, but more research is needed to know for sure.

Scientists continue to study other uses of glutamine, but this research is still in its early stages.

Does L-glutamine reduce belly fat?

No solid evidence supports the idea that taking L-glutamine reduces belly fat or promotes weight loss.

What are the side effects of taking glutamine?

More research is needed to understand the potential side effects of taking glutamine in the long term. For example, it’s possible that supplementing with glutamine may change the way your body uses amino acids to make energy. This is why checking with your provider before taking glutamine (or any other supplement) is important.

Minor side effects of taking L-glutamine for sickle cell disease include:

• Abdominal pain.
• Back pain.
• Constipation.
• Headache.
• Nausea.

You should immediately report an allergic reaction (like a rash or hives) to your provider.

A note from Cleveland Clinic

Glutamine is an abundant, versatile amino acid that’s essential to your health. It’s so essential that it makes sense to think taking glutamine would provide major health benefits. But it’s important to be realistic about the evidence before supplementing glutamine. Taking glutamine can help with sickle cell disease. It may provide your immune system with an added boost in those “conditional” situations when you need more glutamine than your body can make. But there’s no solid evidence that glutamine provides major benefits if you’re generally healthy.

Check with your healthcare provider before taking glutamine or any other supplement. They can advise you on potential benefits and risks based on your unique health situation.