How Much L-Glutamine Should I Take Daily?

Supplements are enticing, but it can be difficult to figure out what works for you and how much to take. Figuring out the proper L glutamine dosage is tough because there's conflicting information. In fact, it might not be necessary to take glutamine at all.

L-glutamine is an amino acid. There are 21 amino acids in total, according to Arizona State Univeristy. Protein, which is one of the building blocks of the body, is comprised of a combination of amino acids. When you eat protein, your body breaks it down into amino acids, which it makes new proteins out of.

Your body makes some amino acids. These are known as non-essential amino acids. Glutamine is one of them. Your body can make glutamine or extract it from muscle. You can also consume glutamine in your diet. Some foods high in glutamine, according to Precision Nutrition, are:

• Cabbage
• Dairy
• Beets
• Fish
• Beans

It's not necessary to go out of your way to get these foods, unless you need glutamine for a medical reason. Since your body makes enough of it under normal circumstance, there's no need to seek it in your diet.

Read more: What Is the Difference Between Glutamate, Glutathione & Glutamine?

Glutamine is also sold as a supplement, and it's fairly popular. The Food and Drug Administration doesn't require supplement labels to be checked before the product is sold. If a supplement printed false advertisements promising you results the FDA would have to catch them and reprimand them.

There are also supplement companies that will cite one or two studies showing their product works, even if there's opposing evidence. The bottom line is that, before you buy a supplement such as creatine and glutamine, do some research to figure out if it truly works or not. Reading the labels won't necessarily help you decipher the truth.

Glutamine, although it's been marketed to weightlifters and bodybuilders, shows almost no benefit for performance. A 2019 study published in Clinical Nutrition reviewed 25 studies on glutamine and came to the conclusion that it doesn't help aerobic performance or the immune system in athletes.

It's a conditionally essential amino acid, which means your body produces enough of it under normal circumstances. According to a November 2018 study published in Nutrients certain conditions like cancer, infections, surgeries and possibly intense exercise can lower your body's reserve of glutamine to dangerous levels. To understand why glutamine has been suggested for athletes, you have to understand what it does and where it's used.

About 40 to 60 percent of the amino acids in tissues in your body are made of glutamine according to the November 2018 study published in Nutrients, making it the most prominent amino acid in the body. Your body naturally produces 40 to 80 grams of glutamine per day, according to the study. It can be used as an energy source for your immune system, normalizes growth hormone and keeps muscles hydrated.

Glutamine also supports your immune system as an antioxidant. When you work out or even just digest food, molecules are sometimes released. These are called free radicals because they're free to bind to other molecules.

Glutamine can help control these free radicals, reducing the amount of damage they can do, according to a December 2014 study in the Journal of the International Society of Sports Nutrition.

In hospitals, glutamine is used for patients who are in critical condition, such as burn victims. It can be given intravenously or as a supplement. An August 2015 study in published in Critical Care shows that burn victims had decreased mortality and shorter stays in the hospital when supplementing with doses ranging from .16 grams per kilogram of bodyweight to .5 grams per kilogram of bodyweight.

Burns are extremely taxing on the body, particularly the immune system. Skin comprises a large part of the immune system, and when it's damaged your body has to work harder to fight infection.

A February 2015 study published in the Journal of Parenteral and Enteral Nutrition showed that glutamine supplementation could help patients with acute pancreatitis. The researchers found that patients who were given glutamine intravenously had fewer infections and a greater chance of survival than those who didn't get glutamine.

While these studies are encouraging, there's still some doubt as to whether glutamine can work even for extremely sick patients. An August 2015 research review published in Medicine showed that groups of patients who supplemented with glutamine were only slightly better off than those who did not in terms of infection and mortality.

Going even further, a November 2016 paper published in Critical Care argued that glutamine shouldn't be given indiscriminately to extremely sick patients. The paper explains that in some cases, patients were given too much glutamine, which had detrimental effects.

Read more: Can You Get All Amino Acids From Being Vegetarian?

Seeing how glutamine helped some patients who were ill or had their immune systems compromised, supplement companies tried to sell glutamine to athletes and gym-goers. The logic is that exercise is damaging to your body, thereby draining it of nutrients like glutamine, which you'd need to replenish to boost your immune function and ability to recover.

Fortunately, your glutamine stores can't be wiped out from exercise, according to the December 2014 study in the Journal of the International Society of Sports Nutrition.

If you are determined to take glutamine for performance and recovery or bodybuilding, there are some loose guidelines you can follow to figure out how much to take. The December 2014 study in the Journal of the International Society of Sports Nutrition explains that some experts believe you should take a set dose, between 20 to 30 grams per day.

Other experts believe you should take 0.3 to 0.5 grams per kilogram of bodyweight per day. There have been mixed results with each, so try both to see what works best. Keep in mind that research is still inconclusive on how much to take and whether or not it can benefit your workouts. You might be better off saving your money and eating protein-rich foods, most of which contain glutamine.