The Complete Guide to L-Glutamine for Bodybuilding

Better recovery, performance boosting, and stronger immunity. Those are some of the claims you frequently hear about L-glutamine supplements. If L-glutamine holds up to the test, it could be a great compound to add to your supplement stack. 

In this article, we will break down L-glutamine for bodybuilding in every way, shape, and form. By the end, you’ll know if it’s an essential supplement or one you can pass on. Let’s get started. 

What is L-Glutamine?

What is L-Glutamine

L-glutamine is a non-essential amino acid. That means your body produces it on its own. However, what really makes L-glutamine special is it’s the most prominent amino acid throughout the body, especially in muscle tissue. Research has found that 80% of the glutamine in our bodies is found in skeletal muscle tissue.1 Pretty cool, right? 

Since glutamine is highly concentrated in the muscle, many claim supplementing with it will lead to many benefits for bodybuilding and athletic performance. When you workout (specifically during intense strength training), you break down muscle fibers that need to recover. That means those highly concentrated glutamine stores get depleted. 

So getting enough glutamine in after a workout can help with recovery. It restores the glutamine levels in skeletal muscle tissue, helping repair damaged muscle quicker, reducing soreness, and ultimately helping you get bigger and stronger in the long run. The faster you recover, the more intensely and frequently you can train. 

Studies have even shown that glutamine supplementation after a workout can help reduce soreness and improve recovery times.2 This is why many in the fitness realm talk about glutamine supplements or recovery formulas that contain glutamine in them. 

What are the Proposed Benefits of L-Glutamine for Bodybuilding? 

Now that we know what L-glutamine is and what it does let’s take a look at the claimed benefits of this supplement. Put an emphasis on the word claimed here. These are just what people in the fitness industry claim about L-glutamine. In the next section, we’ll take a deeper dive into the research of each one to find out if these benefits hold up to the test. 

So the claims for L-glutamine supplementation are:

  • It leads to quicker recovery.
  • It helps increase body mass and power output
  • It can be a helpful aid in weight loss
  • It helps boost the immune system

If L-glutamine can truly do all these things, it would be one heck of a supplement. But let’s look at the research before making any rushed decisions. 

Does the Research Back Up Those Benefits?

Let’s break down the research for each proposed benefit of L-glutamine one by one. 

Does L-Glutamine Lead to Quicker Recovery?

L-Glutamine for Quicker Training Recovery

We already broke this one down earlier, and we know that L-glutamine does indeed help with recovery. It’s one of the main benefits where research does thoroughly point to its effectiveness. 

Do You Need a Standalone Glutamine Supplement to Get Recovery Benefits?

The one aspect where opinions vary is whether a standalone glutamine supplement is needed to get these benefits. Here’s why. 

Studies find that the most effective daily glutamine intake to see effects is between 20-30 grams.3 In the average person’s diet, they’ll get between 3-6 grams of glutamine. However, that’s for the average person who likely doesn’t eat much protein.

In the context of bodybuilding, it can be a bit different. 

  • One scoop of whey protein contains around 3.25 grams of glutamine. 
  • Other lean meats like chicken and lean ground beef contain around 4 grams of glutamine per 4 ounces. 
  • An 8-ounce glass of milk contains 1 gram of glutamine. 
  • A serving of nuts like peanuts, walnuts, cashews, or almonds contains about 1 gram of glutamine. 
  • A single large egg contains 0.7 grams of glutamine. 
  • A 4-ounce serving of greek yogurt contains about 1 gram of glutamine. 
  • Other foods, like rice, corn, tofu, etc., also contain a good amount of glutamine. There are too many to list here. 

In a well-rounded bodybuilding diet, the average person may consume enough glutamine with food and other protein sources alone. For an example of a daily diet for a bodybuilder and its glutamine content:

  • 2 scoops of whey protein = 6.5 grams of glutamine
  • 8 ounces of chicken or beef = 8 grams
  • An 8-ounce glass of milk = 1 gram
  • A serving of nuts = 1 gram
  • 4 eggs = 2.8 grams
  • A serving of greek yogurt = 1 gram

That equals 20.3 grams of glutamine in a day through diet alone. You could argue that simply consuming a whey protein shake after a workout would be sufficient to get enough glutamine in the body to get those recovery benefits. 

However, you could also argue that adding a standalone glutamine supplement and taking about 5-10 grams per day could be beneficial to ensure you get enough glutamine without having to micro-manage your diet. Studies have shown you can safely consume up to 45 grams of glutamine per day, so supplementing with a bit extra wouldn’t hurt you.4

Personally, I don’t take a glutamine supplement. I find that I eat enough of these types of foods where it would be unnecessary for me to add in more glutamine. That said, if you want to, there’s no harm in taking a glutamine supplement. It might help some. 

Also, those who are vegan or have other dietary restrictions may benefit from supplementing glutamine since they would eat less meat, which is the best source of glutamine content. So if you’re vegan, I’d recommend looking into a good glutamine supplement because it could be quite beneficial. 

Does L-Glutamine Increase Mass and Power Output?

L-Glutamine for Mass and Power Output

Some claim that L-glutamine supplementation on its own increases muscle mass and strength. However, studies show that it doesn’t really make a difference. 

One six-week study compared two groups of people that performed consistent resistance training. One group took L-glutamine after exercise, and the other didn’t. By the end of the study, both groups saw equal increases in mass and strength. There was no difference between the two. So L-glutamine had no impact.5 

Other studies have also shown that L-glutamine does not significantly impact exercise performance. 

The one area where it may help increase performance is by helping with recovery. If you recover faster, you can be in the gym more and train harder. 

Does L-Glutamine Help with Weight Loss?

L-Glutamine for Weight Loss

Some also say that glutamine might have a significant impact on weight loss. 

However, studies are very mixed on whether this claim is true. Some small studies, like a 2-week and 4-week study, found that glutamine supplementation helped reduce waist circumference without any other lifestyle or dietary changes.6,7 But these were very short studies. 

Other short studies found that it either made no impact at all, or there was one that said it even led to increases in meal sizes, which would be counterproductive for weight loss.8

Overall, I would say to have low expectations when it comes to L-glutamine for weight loss. It probably won’t have much impact, if any. At the end of the day, eating a caloric deficit and increasing your activity level is still the best way to lose weight. 

Do L-Glutamine Supplements Boost the Immune System?

L-Glutamine to Boost Immune System

There are also claims that supplementing with L-glutamine helps improve the immune system. That could be beneficial in a bodybuilding and exercise performance context. Anything that prevents you from getting sick helps you stay in the gym. As we all know, getting sick can derail both progress and motivation. 

Many of these claims come from the fact that L-glutamine is highly beneficial for burn victims or those who have suffered a serious injury. In these instances, the body’s glutamine levels are severely lowered since it is being used to help heal the injured area. Many medical professionals even prescribe L-glutamine supplements in these instances.9 

Unfortunately, those same results don’t carry over for healthy adults in a bodybuilding or exercise performance context. Anyone who gets enough glutamine from their diet won’t notice any significant improvement in immune function with additional L-glutamine supplementation.  

Summary of L-Glutamine’s Potential Benefits

To give you a well-rounded overview of how glutamine performs, here’s a table breaking down how I’d rate it in each of these four main categories.

Proposed BenefitEffectiveness (Scale of 1-5)
Quicker Recovery3
Increase Mass and Power Output2.5
Weight Loss2.5
Boost the Immune System2
Overall Rating2.5

When Would be the Best Time to Take L-Glutamine Supplements for Bodybuilding?

From analyzing the studies on L-glutamine, the best time to take an L-glutamine supplement would be right after an intense training session. It’s during that window of time when your body may see benefit from restoring its glutamine stores. However, most people will get enough glutamine if they have a scoop of high-quality protein powder after training. 

What is an Optimal Dosage of L-Glutamine for Bodybuilding?

L-Glutamine Optimal Dosage for Bodybuilding

You should be getting between 20-30 grams of glutamine in your diet each day to see benefits for bodybuilding. If you’re going to take an L-glutamine supplement, an additional 5-10 grams on top of what you’re already getting from your diet would be sufficient to see results. However, most people will be fine getting enough glutamine from diet alone. 

Does L-Glutamine Have Any Side Effects?

In most cases, side effects from L-glutamine supplements will be rare. Since we intake glutamine every day, it’s a very safe supplement to take. In rare cases, potential side effects could be:

  • Constipation
  • Nausea
  • Stomach pain
  • Headache
  • Coughing
  • Pain in the limbs

Most people will be just fine and won’t have to worry about these adverse effects. That said, checking with a doctor before taking new supplements is always a good idea. 

What is a Good Cost Per Serving for an L-Glutamine Supplement?

Glutamine supplements are usually pretty cheap. You can generally find it in both powder and capsule form for under $1 per serving. A good glutamine powder will cost around $0.40 or less per serving, and a good glutamine capsule will cost around $0.80 per serving. That means you won’t break the bank if you choose to supplement with it. 

Types of Supplement Formulas that Contain L-Glutamine

In most cases, you will see L-glutamine in either recovery formulas to be used post-workout or in gut or immune health formulas. 

It could be beneficial if you’re thinking about a recovery formula with L-glutamine. 

Otherwise, as we’ve seen from studies, the gut and immune health formulas containing L-glutamine won’t necessarily make much difference. 

You may also see L-glutamine in pre-workout supplements in some rare instances. If you see it in a pre-workout, it probably won’t make much difference to take it before training. 

Bottom Line: Is L-Glutamine Worth it for Bodybuilding?

Overall, I wouldn’t say L-glutamine will be all that beneficial for bodybuilding. It might help as a recovery supplement taken post-workout. The one exception would be those who are vegan or have certain dietary restrictions where they can’t eat much meat. Then supplementing with glutamine could be useful. 

My Overall Rating on L-Glutamine for Bodybuilding: 5/10

Overall, on the scale of usefulness, I give L-glutamine supplements a 5 out of 10 for the purposes of bodybuilding. It certainly won’t hurt you. But those who eat a high-protein diet likely won’t get much benefit out of it. 

FAQ

Does L-Glutamine Help Build Muscle?

L-glutamine will not help build muscle on its own. That said, it may help improve recovery times and reduce soreness which could lead to the ability to train more often and more intensely. 

Is it Ok to Take L-Glutamine Daily?

Yes, you can absolutely take an L-glutamine supplement every day. You consume foods every day containing glutamine, so taking it as a supplement will rarely have any negative effects. 

How Quickly Does L-Glutamine Work?

It can take some time to notice the effects of L-glutamine. It needs to build up in skeletal muscle tissue when taken consistently. It’s often recommended to give it up to 90 days before you feel its full effect. 

Can I Take Creatine and Glutamine Together?

You can safely stack creatine and glutamine together. They have zero interaction and are both natural compounds produced by the body on their own. 

Does Glutamine Make You Lean?

There is no conclusive evidence that L-glutamine will help with fat loss or weight loss in any significant way. The best approach is to eat a calorie deficit and get more active if you want to lose weight. 

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Pierce Reiten
Pierce Reiten

Pierce Reiten is an NASM certified personal trainer with over a decade of experience in the gym. He's passionate about providing information to help you improve your fitness and life.

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