Key takeaways
- L-glutamine supplements may support health when the body is not producing adequate amounts, such as during illness or injury.
- Supplements typically provide around 200 mg to 1,000 mg L-glutamine per serving.
- Our top choices for L-glutamine supplements are Thorne for quality and Nutricost for taste and affordability.
| Price | Form | Dose per serving | (Total servings) | Price per serving | |
| Thorne | $24, $63 | capsule, powder | 500 mg | 90 | $0.26, $0.70 |
| Nutricost | $17.97 to $32.97 | powder | 500 mg | 50 to 200 | $0.16 to $0.35 |
| Double Wood | $14.95, $24.95 | capsule, powder | 1,000 mg | 60, 100 | $0.24 |
| Designs for Health | $69.99 | powder | 200 mg | 30 | $2.25 |
All supplements we feature on Healthline have passed our rigorous vetting criteria, which evaluates brands and products for quality, health claims, certifications, and more.
To select the best L-glutamine supplements, we considered the following:
- Testing: We prioritize brands that put their products through independent, third-party testing to establish purity and potency.
- Ingredients: We look for brands that use high quality ingredients and limit or avoid artificial flavors, fillers, and preservatives.
- Certifications: We looked for brands that offer products with additional certifications from third-party organizations, such as NSF.
- Reputation: We choose brands approved by our nutrition experts and with positive customer reviews.
- Price: We select products that suit various budgets while providing good value.
Our Medical Standards and Insights team has carefully researched and vetted over 11,000 products and services. We fact-check health claims, evaluate ingredients, and look into each brand’s reputation before sharing products and services on Healthline.
To choose the brands on this page, we considered all the vitamin brands that passed our vetting process. Then, we personally tested some of them to narrow down our list even further.
L-glutamine is an amino acid that is important for various bodily functions. It is sometimes referred to as simply glutamine, though this has a different structure than L-glutamine.
The body needs essential and nonessential amino acids to create various proteins. A nonessential amino acid, like L-glutamine, is a protein the body can produce itself. A person does not need to get it from food.
Most healthy people do not require L-glutamine supplementation. However, some people may benefit from L-glutamine supplements when their body’s reserves are low. Deficiencies may occur when the body is experiencing strain on glutamine supplies, such as during illness or injury, or after strenuous exercise.
Current research suggests that L-glutamine benefits may include supporting muscle growth and recovery after exercise, managing gastrointestinal conditions, and supporting immune system function.
Just a few studies showing benefits to L-glutamine supplementation are listed below:
- Athletic performance and recovery: A 2024 study found that taking L-glutamine after intensive combat sports training improved hormone levels, mood, and resistance to respiratory infections. A 2020 study among older adults in an exercise program experienced greater health benefits when taking L-glutamine supplements.
- Gastrointestinal health: A 2021 study suggests that, in combination with a low FODMAP diet, L-glutamine supplementation may help manage irritable bowel syndrome (IBS) symptoms.
- Treatment applications: A 2020 study found that L-glutamine supplementation may help prevent the onset and progression of atrial fibrillation. A 2024 study supports that L-glutamine supplementation effectively manages sickle cell disease complications.
While L-glutamine supplementation has many proven uses, most healthy people will not need to take it as their body should produce enough.
People considering taking L-glutamine regularly should speak to a healthcare professional first, particularly if they have existing conditions or are taking any medication.
Our pick for best L-glutamine brand is Thorne, due to the company’s commitment to research and quality.
Thorne offers L-glutamine supplements in capsule or powder form, providing 500 mg of L-glutamine per serving.
L-glutamine supplements are typically available in powder or capsule forms.
Little research is available to conclude that any form is best. However, many people opt for powder supplements as it may be more readily absorbed in the body.
Taking L-glutamine daily may offer some health benefits, such as improved exercise performance and recovery, management of gastrointestinal health, and support of immune function.
However, most healthy people do not require L-glutamine supplements as the body should produce adequate supplies.
Speak to a healthcare professional to determine if L-glutamine supplementation is safe and worthwhile for your health goals.