The 5 Best L-Glutamine Supplements To Make You Feel Invincible

Let’s be honest: Sometimes, you just hit a wall.

You usually can’t wait for a workout, but for some reason your head isn’t in it today or you’re having digestive issues or you feel like you’ve plateaued in recent workouts.

It’s unfortunate, because all of your workouts should make you feel amazing and strong and powerful.

Luckily, there’s a way to ensure you always get a great lift or CrossFit session or calisthenics workout.

With L-glutamine, a natural amino acid, you no longer have to worry about another bad day at the gym.

In this comprehensive guide, you’ll get a full overview of the L-glutamine benefits, foods rich in L-glutamine, dosage, side effects, and the best -L-glutamine supplements for you to up your game.



BulkSupplements Pure L-Glutamine
  • Supports digestive health
  • Resealable bag
  • Affordable option
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Optimum Nutrition L-Glutamine Capsules
  • Highly concentrated
  • Convenient capsule form
  • 500mg per capsule
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NOW Sports Powder
  • A-rated GMP certification
  • Immune support
  • Vegan-friendly
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NutraBio 100% Pure L-Glutamine Powder
  • No fillers
  • No proprietary blend
  • Supported by third party testing
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Nutricost L-Glutamine Powder
  • Unflavored
  • Gluten-free
  • Supported by third party testing
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The Five Best L-Glutamine Supplements

For those who think TL;DR, here is a quick list of the five premier supplements of L-Glutamine:

What is L-Glutamine?

It’s what is known as a conditionally essential amino acid; this means L-glutamine isn’t essential for the body, except for when you’re ill or stressed.

Your body makes it in large quantities, meaning you don’t need to take in L-glutamine through your diet unless you’re ill, have a digestive disorder like IBS, or you’re feeling stressed.

Because L-glutamine is an amino acid, it is involved in protein synthesis in your body.

Regularly known as “the building blocks of life,” amino acids combine to form protein, which helps build up muscle, break down food, and repair body tissue, among other processes.

So L-glutamine, as well as the other aminos, is really important for your body, especially considering it’s “the most abundant amino acid in the bloodstream.

What are the Top L-Glutamine Benefits?

Seeing as it’s all over the place in your body, you can see that L-glutamine has a wide range of benefits. In fact, L-glutamine provides the following for you and your wellbeing:

Improved Digestive Function

If you have a digestive issue, you may benefit from glutamine supplementation. For those with gut problems and intestinal issues, L-glutamine serves as a vital nutrient to heal the intestines, any ulcers you may have, IBS, and leaky gut syndrome. Like an amino acid Band-Aid for your digestive and excretory systems.


Improved Immune Function

When you workout, your glutamine levels deplete. This affects your immune system, which is why bodybuilders are more susceptible to illness. Taking a glutamine supplement restores your glutamine levels, keeping you healthy and maintaining your normal routine.

Better Cognition

For your brain, L-glutamine “is an essential neurotransmitter…and helps with memory, focus, and concentration.” It helps keeping your mind sharp, aiding in mental health. Glutamine supplementation is beneficial for older athletes in combatting cognitive decline, as well as giving all athletes better focus to get through an intense workout.

Better Muscle Recovery

Of course, if it helps heal and improve the other areas of your body, it has an effect on workout recovery. L-glutamine improves athletic performance by having your body run as efficiently as possible. It also reduces muscle breakdown, as well as enhances recovery from endurance exercises. Plus, L-glutamine could help in reducing delayed onset muscle soreness (DOMS). Improving your glutamine intake can help you achieve your goals of building lean muscle mass while ensuring you’re read for your next round of intense exercise.

For older athletes at risk of age-related skeletal muscle loss (sarcopenia), improving glutamine stores while engaging in consistent resistance training can also help maintain muscle mass with age.

Better Body Composition

L-glutamine supplementation helps burn body fat too; metabolism and cellular detoxification are increased when there are higher L-glutamine levels in the body. This is because L-glutamine aids in the production of human growth hormone and contributes to better digestion.

Improves Insulin Suppression

Here’s an interesting one: taking an L-glutamine supplement actually cuts down on your sugar and alcohol cravings. This amino acid helps “suppress insulin and stabilize blood glucose.” So, L-glutamine also aids people with diabetes.

If it stabilizes blood glucose, suppresses insulin, which in turn saves muscle mass and recovers your entire body and keeps you mentally sharp, L-glutamine is a must have supplement in your regimen.

What Foods Are High in L-Glutamine?

Before you start looking for the best L-glutamine supplements, know that the best dietary supplement will always be real food. Thankfully, there are a lot of foods out there that have a decent amount of this amino acid.

dietary glutamine

You can easily include this conditionally essential amino acid in your diet.. Interestingly, most of the foods that are high in L-glutamine are known as “superfoods” or healthy for you.

  1. Cow Products: Foods like bone broth, grass-fed whey protein, grass-fed raw dairy, and grass-fed beef are excellent sources of L-glutamine. This makes sense, because bovine products like meat and dairy are superior sources of protein, which involves a huge array of amino acids.
  2. Specific Vegetables: Cabbage, asparagus, brussel sprouts, carrots, beets, celery, kale, and broccoli are wonderful for getting your L-glutamine fix, especially if you’re a vegan.
  3. Spirulina
  4. Venison, Turkey, Chicken, Fish, and Eggs (more amazing protein sources)
  5. Wheat
  6. Papaya

These are all great foods to get your L-glutamine in, but unfortunately, seeing as your body requires a ton of this amino acid, it might only cover a small percentage of your requirement. Therefore, taking a dietary supplement is necessary in some situations.

How Much Glutamine Should You Take Daily?


Now, when it comes to supplementation, you need to be careful with L-glutamine along with every other potential supplement.

Discuss with your doctor, be sure you need it or your body can sustain extra L-glutamine first before taking it. Once that’s out of the way, it comes down to a matter of dosage.

To start, it would be good to stay within the 500-1,500 mg range.

Keep in mind, your body has a ton of L-glutamine as it is, and your food has L-glutamine as well. So it’s best to go with a small dosage to begin with.

Once you feel confident with moving up, adults can get into the 5,000-15,000 mg range. But this should be the absolute max.

This is essentially a case-by-case question. Test it out yourself and see what amount of L-glutamine your body likes through supplementation.

(A quick note: If you decide to try the higher amount of L-glutamine, make sure to supplement B vitamins as well. Specifically, B12 “controls glutamine buildup in the body.

When Should You Take L-Glutamine?

For performance and recovery purposes, taking L-glutamine after a workout is optimal.

L-glutamine powder

This is where L-glutamine improves the production of HGH (Human Growth Hormone), which is the element that builds muscle tissue, lowers body fat, and ramps up your metabolism.

Right after a workout, where your immune system is at an all-time low, it helps protect your body from disease, which is extremely important in a gym setting.

For those who are insulin-sensitive, diabetic, or have problems regulating their blood sugar, it’s pivotal to supplement L-glutamine later in the day.

Reason being is in the morning your insulin is suppressed and you aren’t subject to those sugar cravings or spikes in blood sugar.

Once you break your fast, though, the insulin in your body is working to stop using fat for fuel and working to break down those sugars you’ve ingested.

If you take L-glutamine, say, during the afternoon, sugar cravings, insulin will be suppressed, and less sugar that’s already in your body will be used.

If your dosage is somewhere in the 500-1,500 mg range, it’s easiest to supplement once daily.

However, if you’re getting up into the thousands of milligrams, you might have to split up times to take it. Also, again, this is a personal preference; figure out what times of the day works well for your own schedule and how you feel.

How Long Does It Take For L-Glutamine To Work?


As far as ingesting it as a supplement, L-glutamine will enter the bloodstream fairly quickly, like most supplements.

However, if you use it to repair leaky gut or your intestines, the answer is, “It depends.” Another personal dilemma, it will be based on the individual.

For workout recovery, fat burning, and muscle building, it should take effect within the same day.

And once you’re on a consistent routine of taking L-glutamine, you should be able to see the effects continuously.

Of course, please be careful in not overusing L-glutamine supplements. Unless you are using it for serious bodybuilding or crazy intense workouts, stay in the lower range and benefit from the small kick it gives your entire body.

If you are working for a show or a competition, however, you should give the 5-15 gram range a try.

You should be able to see changes in both performance and recovery, as well as mental clarity, within a few days.

Types of L-Glutamine

There are two main types of L-glutamine:

The second option is what’s known as an L-glutamine peptide. In essence, an L-glutamine peptide is more stable and easier for the body to absorb.

Most studies are done with the free form version, but either are solid options for your supplement routine.

L-Glutamine Powder vs. Capsules

The million dollar fight between powder and capsules rages on. Other than “it’s really up to the person taking the supplement,” here are the differences, pros, and cons of both types:

Glutamine Powder:


Powdered L-glutamine dissolves well into any beverage you care to drink after your workout, like water or a sports drink. The taste is mild and almost unflavored, so it shouldn’t be noticeable.

Of course, with it being a powder, it isn’t simple to travel with, and you have to have a drink with you to mix it.

Yet another positive with powders is the cost; similar to other supplements, L-glutamine is cheaper in powder form than capsule.

Glutamine Capsules:


The cool thing about capsules is how much punch they can pack into each pill, at least for lower doses.

Measuring is straightforward, and taking them anywhere is super convenient, but at 500 mg, you need to pop a lot of capsules to get up to your desired dosage.

While this option is cheap as well, it doesn’t quite stack up to the powders.

So, if you want a cheap, mixable, tasteless option that is tough to travel with, go with powders.

Or, if you want an easy, travel friendly choice that requires a trough of them per dose, go with capsules. Either way, personal inclination will rule this battle.

L-Glutamine Side Effects

Here’s some good news: You normally won’t experience any severe side effects with this amino acid, so long as you don’t overdo it.

Sadly, there are those unfortunate few who are allergic to L-glutamine supplements. Certain medications can also be impacted by your glutamine supplement, which is why it’s always important to discuss with your doctor.

But, assuming you aren’t in that category, there are only a few side effects you should look out for:

  • Headaches, dizziness, feeling tired
  • Swelling or pain in certain areas of your body, such as your hands, feet, and back
  • Rash, itching, dry mouth, increased sweating, runny nose
  • Nausea, vomiting, stomach pain, and gas, which are the worst side effects

As you can see, these all have something to do with your body’s ability to recover, something L-glutamine does for your body.

The extra rush caused by an increase in L-glutamine to the places in the body where it does its work might experience these symptoms.

For example, this amino acid aids in mental clarity; too much or a concentrated amount of L-glutamine could result in headaches.

Keep in mind, all of these side effects are uncommon and, unless you are allergic or already have enough L-glutamine in your system, you shouldn’t have an issue.

Just make certain you don’t go above 15 grams per day if you’re a serious bodybuilder or weightlifter.

Top L-Glutamine Supplements Reviewed

BulkSupplements Pure L-Glutamine

  • Approx. $0.04 per serving
  • Convenient packaging
  • No Fillers
Bulk Supplements L-Glutamine

Honestly, you can never go wrong with BulkSupplements due to their quality products. For their Pure L-glutamine powder, there’s no exception.

Staying true to the name, this is 100% pure glutamine, with no other ingredients.

There’s 500 servings at 1,000 mg per serving, so it should last you between 2 months and 3 months.

And at four cents per serving, that’s one killer deal. (You can go even cheaper if you buy in bulk!)

This is no-nonsense, simple as could be, pure L-glutamine. If you want the benefits and zero fluff, BulkSupplements should be your supplement weapon of choice.

Optimum Nutrition L-Glutamine Capsules

  • Approx $0.10 per serving
  • High-quality brand
  • Concentrated formula
L-Glutamine Capsules

Often lauded as the King of Supplements, Optimum Nutrition glutamine comes up with the only capsule option on our list.

What’s impressive about this L-glutamine supplement is how basic it is.

Other than the amino acid and gelatin for the shell, the only other ingredient is magnesium stearate, a simple salt that acts as a white, water-insoluble powder. (A tasteless, sturdy filler.)

The serving size in a capsule is one gram, with 120 total pills per bottle. This comes out to about 10 cents per serving, which isn’t bad for a capsule.

Opting for a trusted source and a big brand is sometimes the smartest option.

If you want a high-quality capsule that gets the job done, Optimum Nutrition Glutamine is the best in the biz.

NOW Sports L-Glutamine Powder

  • Approx. $0.17 per serving
  • Pure L-glutamine
  • Nitrogen transporter
Now L-Glutamine Powder

Another free form L-glutamine that doesn’t have any unnecessary ingredients, NOW Sports Powder is a great decision.

A widely-trusted brand, NOW gives you the quality you want and need for an L-glutamine supplement.

You get a full pound of the stuff, which translates to 90 servings at five grams per.

The difference between NOW and the first two choices on this list are few and far between. Personal preference rears its head again, and you must decide which brand you like the best.

NOW Sports Powder is another can’t-be-beat brand and product that will give you the results you want: Better recovery, more muscle growth, and extra brain power!

NutraBio 100% Pure L-Glutamine Powder

  • Approx $0.18 per serving
  • Available in 500g and 1kg containers
  • No fillers or excipients
NutraBio Glutamine

This next choice is also a powder, which goes to show you it holds a little power over the capsule products in terms of quality, purity, and price.

NutraBio can claim all of these characteristics confidently.

They proudly put “ABSOLUTELY NONE” in their “Other Ingredients” list, so this is 100% pure glutamine, folks.

This is also a 5-gram serving, and they give you 100 servings per container. So this one is a little smaller than the others, but it should still last you almost 2 months based on dosage.

This tasteless supplement is incredibly affordable, fermented, and pharmaceutical grade.

To decrease muscle deterioration and feel amazing and not sore after workouts, NutraBio Pure L-Glutamine Powder is a great way to go.

Nutricost L-Glutamine Powder

  • $0.04 cents per serving
  • Bulk 1Kg container
  • Pharmaceutical grade
NutriCost L-Glutamine

For an effective, pure, affordable bulk option of glutamine powder, try Nutricost. With 200 servings per bottle and third-party lab testing, this is the best glutamine supplement for newcomers to the world of supplementation.

This non-GMO, gluten-free pure glutamine powder can help you achieve your fitness goals without breaking the bank. For the record, Nutricost makes a great BCAA supplement too!


L-glutamine is a very essential amino acid for your whole well-being.

Not only does it aid in recovery and strengthen your immune system, intestines, and gut, it also increases brain function and is a big player in human growth hormone.

You can get a lot of L-glutamine in your diet because there are many foods high in protein. The amount varies for each person, but it shouldn’t break the bank as a supplement.

Get it in a pure, free form powder to mix in your post-workout drink, or take a couple pills a few times daily, and you’ll get all of the amazing benefits of extra L-glutamine. And what’s more, the side effects aren’t dangerous and aren’t a problem unless you take too much.

There are a lot of great supplements out there, so do your due diligence in finding the right one for you! Once you do, you’ll be nearly invincible…nearly.