Today, I’m writing about glutamine. And I’m pretty pumped about it. As the most abundant amino acid in your body, glutamine is a big deal.
We need glutamine for muscle protein synthesis, muscle recovery, gut health, and fueling our immune system (among other things).
In this article, I’ll break down the research on glutamine. Plus, I’ll give you my list of the best glutamine supplements on the market.
Glutamine or L-glutamine is one of the 20 amino acid building blocks in your body.
Many cells rely on glutamine for energy, especially those in your skeletal muscles, small intestine, kidneys, liver, and immune system.
Glutamine is known as a conditionally essential amino acid. Your body usually makes enough glutamine from other amino acids. However, if you’re under stress from illness, injury, or intense exercise, making glutamine becomes trickier. That’s the conditional part. In this case, eating more protein-rich foods and supplementing can help.
Glutamine has a reputation as a must-have amino acid for supporting gut health, boosting immune function, and building muscle mass.
Here are some of the potential health benefits of L-glutamine supplementation:
In recent years, glutamine powder has grabbed the spotlight as a gut-healing supplement. Holistic and alternative doctors recommend it for anyone with digestive problems, IBS, inflammatory bowel disease, food sensitivities, and everything in between.
As it turns out, there is some truth behind these claims.
Glutamine is the major fuel source for the rapidly dividing cells lining your small intestine. It repairs and maintains the gut lining, helping to prevent intestinal permeability or “leaky gut.” This is where tight junctions in the gut wall become permeable, allowing undesirable particles to enter the bloodstream.
This 2019 study found 5 grams of glutamine daily improved intestinal permeability and IBS symptoms after a gut infection. Another small trial found glutamine may prevent leaky gut in long-distance runners. However, the participants used relatively high doses.
Maintaining the protective gut barrier is essential for millions of tiny finger-like villi to absorb nutrients in the small intestine.
However, while glutamine may support a healthy gut lining, there is no evidence to suggest it improves digestive conditions.
Putting your body under stress due to a demanding training regime depletes your cellular and blood glutamine levels. So, it stands to reason that replenishing your glutamine stores may fight fatigue and reduce muscle tissue loss.
This study found taking glutamine improved muscle recovery and reduced soreness after performing eccentric exercises.
Glutamine may be especially useful for older people (who have greater amino acid needs). A study on women aged 60-80 found glutamine improved knee muscle strength and power during exercise.
Full disclosure, other studies suggest young people who already eat a protein-rich diet probably won’t see noticeable performance benefits. Further, claims about glutamine aiding in weight loss directly are a big stretch.
That said, athletes and those dealing with stress may want to add glutamine to their supplement stack.
Here is our list of the 8 best glutamine powders and capsules on the market.
All the products are made according to current Good Manufacturing Practice (cGMP) standards and thoroughly tested for safety.
*Note: We have affiliate links throughout this article, which means we receive a commission if you buy from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying things like banner ads. Those suck.
Kaged has a pure, bioavailable glutamine powder. It’s 100% plant-based, unflavored, non-GMO, and free from fillers and additives.
Each scoop of their powder delivers 5 grams of pure l-glutamine – a free form of glutamine that your body recognizes. Plus, it’s naturally fermented for optimal absorption. And, as a vegan-friendly powder, you can be sure you’re not ingesting untested animal by-products (eww!).
The powder dissolves easily in liquids, making it ideal for adding to water, smoothies, protein shakes, and pre-or post-workout recovery drinks.
Kaged is certified by Informed-Sport, the global gold standard for banned-substance testing. This makes the products safe for athletes at all levels.
A 500-gram container costs just $24.99 and contains 100 servings. That’s roughly 25 cents per serving. It’s a simple, quality, quality, that lives up to the Kaged standard.
For all these reasons, Kaged Glutamine Powder is our #1 choice.
Micro Ingredients produces US-made nutritional powders free from fillers and nasty additives and preservatives. And their glutamine is no different.
Each serving contains 3 grams of free-form, plant-based L-glutamine powder. It’s non-GMO, non-irradiated, gluten-free, and sugar-free.
The powder is tasteless. You won’t have an issue mixing it in water, juice, a smoothie, or a protein shake. However, some people prefer to use it to make capsules.
A 1-kilogram bag (2.2 pounds) will keep you going for several months and sells for just $38.34.
If you’re looking to buy l-glutamine in bulk at a great price, Pure Bulk has what you need.
Their pure glutamine is just that: pure, premium-quality l-glutamine without fillers, gluten, yeast, or any dodgy ingredients.
It’s available in loose powder, vegetable capsules, and gel capsules. The powder comes in different sizes, from 50 grams to 1.5 kg. Otherwise, they have bottles of 120 or 300 capsules.
Pure Bulk products are third-party tested for identity, purity, and potency (if you don’t believe me, you can request a copy of the test results).
Onnit Glutamine Powder is simple and effective. It’s unflavored l-glutamine with no fillers and unnecessary ingredients. A container provides 60 5-gram servings.
It sells for $21.99. But you can get 15% off if you subscribe to receive a regular glutamine delivery. I know it sounds like a sales pitch, but the subscription really is convenient – and you can specify how often you want your refill delivered.
Onnit products are Informed-Sport tested for banned substances, making them 100% competition safe.
Transparent Labs has a plant-based glutamine powder with fermented vegan branched-chain amino acids (BCAAs), coconut water powder, and vitamin C. BCAAs are three amino acids – leucine, isoleucine, and valine – that promote muscle protein synthesis and exercise recovery.
Each serving of powder delivers:
It comes in the yummiest flavors. You can choose between sour green apple, tropical punch, strawberry lemonade, blue raspberry, and orange. Plus, it’s free from fillers, artificial sweeteners, and colorants.
It’s slightly pricier at $39.99 for a container of 30 servings. However, you’re getting other nutrients to support muscle growth and recovery.
MuscleTech is a premium supplement brand supplying best-in-class sports nutrition to elite athletes and part-time exercise enthusiasts.
Each serving of their Platinum Glutamine delivers 5 grams of 100% pure l-glutamine powder free from banned substances. The unflavored powder is HPLC-tested for purity; each serving is free from fillers, additives, bacteria, and toxins.
MuscleTech manufactures science-backed supplements according to strict cGMP standards.
NOW Sport L-Glutamine Capsules deliver 1000 mg of cGMP-quality assured l-glutamine per serving.
It’s vegetarian, kosher, and non-GMO. And you can choose between bottles of 120 or 240 capsules.
Now Sports is certified by Informed-Sport to contain no banned substances. Competing athletes have peace of mind when taking this glutamine supplement.
That said, if you want a higher daily dose, you’re better off choosing one of the glutamine powders on the list.
Optimum Nutrition Glutamine Capsules are ideal if you want to start with a lower dose. Each easy-to-swallow capsule contains 500 mg of pure l-glutamine.
A bottle has 240 capsules. Unfortunately, the capsules contain gelatin and aren’t suitable for vegans.
Optimum Nutrition has Informed-Sport registered manufacturing sites. Regular on-site inspections and swabbing ensure they follow the high standards for quality. That said, the testing standards aren’t as strict as others on this list.
We ranked these supplements, but we want you to decide on the best product for your needs.
Here are some factors we considered while researching the products.
Unscrupulous companies take advantage of the fact that the FDA doesn’t regulate the dietary supplement industry. There are a ton of crappy supplements out there.
For this reason, we recommend brands that adhere to cGMP regulations. We also prioritize companies that use third-party testing for banned substances.
Buying from our list ensures you get the purest and safest glutamine supplement.
We chose supplements wit L-glutamine, a well-absorbed form of glutamine found in dietary sources. The products listed are also non-GMO and free from additives.
We included l-glutamine powder and capsules, so you can pick what works for you.
Capsules are convenient. But glutamine powder is more cost-effective and allows you to adjust the dose with ease.
Most of the products listed deliver between 3-5 grams of l-glutamine per serving. However, we also included lower-dose capsules for those who want to build up the dose slowly.
We know that investing in your wellness can be pricey. But the best glutamine supplement doesn’t have to be the most expensive.
We weighed the cost against the number of servings per container, the dose, and the quality of each product.
Just as glutamine fuels your gut lining, it also fuels immune cells like lymphocytes, macrophages, and neutrophils. These guys give your immune system the firepower to fight off infection-causing pathogens. In fact, it’s often recommended for immune-compromised individuals.
In addition, it may reduce immune suppression due to overtraining. This study found taking glutamine after endurance exercise significantly reduced the risk of getting a cold.
But, if you’re generally healthy, glutamine supplements won’t make your immune system bulletproof.
This study found 30 grams/day of glutamine powder for six weeks significantly improved fasting blood glucose levels in type-2 diabetics. It also improved glycated hemoglobin (HbA1c) – a marker of long-term blood sugar control. The glutamine group also dropped body fat and reduced their waist circumference.
However, this was just one small study, and the dose was significantly higher than is typically recommended.
Yes, glutamine is in protein-rich foods such as eggs, beef, chicken, fish, dairy products, tofu, legumes, rice, and corn.
Most people get enough glutamine from a varied diet rich in high-quality protein. However, vegans, vegetarians, people with digestive disorders, cancer patients, surgery patients, and endurance athletes may need support from supplements.
There are a few forms of glutamine, which can be confusing. L-glutamine is the most bioavailable form produced by the human body – it’s also the form found in most supplements.
Whether you pick glutamine powder or capsules depends on your preference; both forms will boost your glutamine levels.
That said, glutamine powder has a slight edge over pills as it dissolves easily in liquids and may be easier to absorb. Plus, the powder is better if you want to take a higher dose
On the other hand, glutamine capsules are convenient to take on the go (and you won’t taste them).
There is no official recommended dosage for glutamine. However, most experts suggest 5 grams of glutamine taken 1-2 times daily with food.
Those engaging in prolonged exercise and intense training (like bodybuilders and endurance athletes) may need up to 10 grams twice daily before or after an intense workout.
Glutamine works well in combination with other fitness supplements.
Glutamine is an amino acid naturally produced in the body. As a supplement, it is considered safe for most people. Taking up to 20-30 grams per day has shown no ill effects.
However, there is a risk of mild side effects in some people – like bloating, heartburn, stomach pain, or nausea. In addition, cancer patients using l-glutamine supplementation to reduce chemotherapy side effects should know it may stimulate tumor growth.
Always speak to your doctor before taking any new supplement.