Best L-Glutamine Supplements

Amino acids, essential building blocks of proteins, are pivotal to numerous enzymatic reactions in the body. Their proper intake—or lack thereof—is linked to significant health issues, including obesity, insulin resistance, diabetes, gut health, and immunity. One such amino acid, glutamine, plays a crucial role in these areas. Supplementing with glutamine can help synthesize proteins, build muscle, enhance recovery from exercise, boost immunity, improve gut health, and potentially accelerate weight loss. While scientific research supports many of these claims, some areas still require further investigation.

Recommendations

Top Choice: Revive’s Glutamine Supplement

• Offers a higher strength, allowing for a 10g dose with the same amount of powder used for 5g in other brands.
• Gluten-free, third-party tested, and mixes well into plain water.
• Transparent about testing results, available publicly.
• Up to 15% off with a subscription on Amazon.

Evaluation Criteria

Our evaluation of glutamine supplements is based on several criteria: effectiveness, safety, cost, and customer service. Effectiveness is our primary concern, closely followed by safety. We also consider cost and customer service, which can influence your decision.

Effectiveness

Winner: Revive Glutamine Revive’s glutamine supplement stands out for its higher dose of 10g per serving, compared to the typical 5g in other brands. This higher dose can bolster the intestinal lining against leaky gut syndrome and enhance immunity, particularly for those undergoing major surgeries. Transparent Labs is a strong runner-up, especially for those using glutamine as a workout supplement, thanks to its combination of glutamine and branched-chain amino acids (BCAAs).

Safety

Winner: Transparent Labs Transparent Labs ensures safety through third-party testing, vegan-friendly ingredients, and allergen-free formulations. The company provides detailed information about each ingredient, enhancing transparency and consumer trust. Revive also scores high for safety, with a vegan-friendly, soy-free, and gluten-free formula.

Cost

Winner: Kaged Kaged offers the best value, with 100 servings per container at a lower cost per gram than other brands. Additional discounts are available for military personnel, teachers, students, and first responders.

Customer Service

Winner: Kaged Kaged excels in customer service, offering quick shipping, comprehensive notifications, and free workout guidance on their website. They also provide a 60-day satisfaction guarantee and flexible subscription options.

Detailed Product Reviews

Revive Glutamine

• High 10g dose per serving.
• Third-party tested for purity and accuracy.
• Gluten-free, soy-free, and vegan-friendly.
• Available for up to 15% off with a subscription on Amazon.
• Short 15-day return policy, with refunds issued as gift cards.

Transparent Labs BCAA Glutamine Powder

• Combines 5g of glutamine with 8g of BCAAs for improved exercise performance.
• Includes vitamin C for immunity and gut support.
• Coconut water powder for hydration and renal health.
• Available in four flavors: sour green apple, tropical punch, strawberry lemonade, and blue raspberry.
• Subscription discounts available.

Kaged Glutamine

• Offers the lowest cost per gram.
• 100 servings per container.
• Third-party tested and Informed-Sport certified.
• 60-day satisfaction guarantee and flexible subscription options.
• Often sold out and testing results not readily available.

Best L-Glutamine Supplement

• L-Glutamine:
  • Best Overall:
    • Thorne L-Glutamine
      • $23 at Amazon
  • Momentous L-Glutamine
    • $39 at livemomentous.com
  • BCAA Sport Hydration Powder:
    • Cellucor BCAA Sport Hydration Powder
      • $23 at cellucor.com
  • Glutamine:
    • Best Budget Supplement:
      • MusclePharm Glutamine
        • $25 at Amazon
    • Klean Glutamine
      • $58 at kleanathlete.com

“Glutamine supports immune system functionality, though supplementation shows benefits primarily when protein intake is severely low or the immune system is under extreme stress, such as post-major infection, surgery, burns, or specific radiation treatments,” asserts registered dietitian Brian St. Pierre, MS, RD, CSCS, Director of Performance Nutrition at Precision Nutrition.

Though healthcare professionals frequently recommend glutamine supplements for significant medical needs, it is also marketed to enhance athletic performance and support gut health. However, current evidence does not substantiate improvements in athletic performance, although some studies suggest it might aid in strength recovery and muscle soreness reduction in men, notes Draayer. These findings, however, are inconsistent and necessitate further research.

This amino acid also significantly impacts gut health, potentially benefiting certain athletes. “Glutamine may help maintain gastrointestinal integrity during prolonged endurance exercise, potentially mitigating post-exercise illness risk,” Draayer suggests, while emphasizing the need for more robust research.

Experts concur that most healthy individuals are unlikely to benefit from L-glutamine supplements. However, those who subject their bodies to extreme physical stress, such as marathon or Ironman training, might see potential benefits. “Glutamine is generally safe for most healthy adults at doses below 40 grams per day. Thus, supplementing might pose no harm if financially feasible,” Draayer adds.

What to Consider

Dose: There is no universally accepted dosage for glutamine supplementation, and excessive intake could result in ammonia accumulation. “Appropriate dosage varies based on individual needs and reasons for supplementation. Consulting a doctor or dietitian is advisable to determine the correct dosage,” advises Draayer. Most L-glutamine supplements are available in 1 to 5-gram doses.

Form: Glutamine supplements come in capsules and liquids, but powder form is most common, to be mixed with water. “The best form depends on personal preference and cost,” Draayer suggests.

Certifications and Quality: Quality is paramount when selecting an L-glutamine supplement. As supplements are not FDA-regulated, ensuring the package contents match its claims is critical for safety and efficacy. Look for third-party verification certifications such as USP, NSF, or Informed Choice Certified on the label.

How We Selected

To identify the best L-glutamine supplements, we consulted experts and reviewed popular products, evaluating third-party verification, ingredients, dosage, certifications, price, and reviews. All listed products have third-party verification and certifications by USP, NSF, or Informed Choice, ensuring purity and potency.

L-Glutamine

Best Overall:

• Thorne L-Glutamine
  • $23 at Amazon
  • Pros:
    • NSF Certified for Sport
    • Free from gluten, soy, and dairy
    • 90 servings per container
    • Unflavored and tasteless
  • Cons:
    • Only powder is NSF-Certified; capsules are not

“Thorne’s L-glutamine powder is a favorite for its NSF Certification and ease of dissolution,” says Nicole Ibarra, RD, LD, a registered dietitian and sports nutrition expert. Thorne’s product, backed by third-party verifications, guarantees it’s free from substances banned for athletes, providing additional assurance.

Unflavored and tasteless, the powder can be mixed with water or other supplements like protein or creatine. Each container offers ninety 5-gram servings, with an option to save 20% via subscription.

L-Glutamine

Momentous L-Glutamine

• $39 at livemomentous.com
  • Pros:
    • Vegan, gluten-free, and soy-free formula
    • Save 20% with subscription
    • Informed-Sport Certified
  • Cons:
    • Bag packaging can be difficult to seal and scoop from

For an affordable yet high-quality option, consider Momentous L-glutamine powder. Each serving contains 5 grams of unflavored L-glutamine powder that blends with water or smoothies. Free from sweeteners, colors, and additives, it is vegan and gluten-free.

Packaged in a resealable bag, it saves pantry space but can be challenging to scoop from towards the end. Each bag provides 60 servings at $0.64 per serving, with further savings through subscription options.

BCAA Sport Hydration Powder

Cellucor BCAA Sport Hydration Powder

• $23 at cellucor.com
  • Pros:
    • Combines BCAAs and electrolytes for recovery and hydration
    • NSF-Certified for Sport
    • Athlete-focused formulation
    • Widely available online and in stores
  • Cons:
    • Contains artificial colors and sweeteners
    • May not be suitable for rest days

If muscle recovery is your goal, Cellucor BCAA Sport Hydration Powder combines branched-chain amino acids and electrolytes with glutamine to aid post-workout recovery. Each serving provides 8.25 grams of amino acids and 2 grams of glutamine, with studies indicating potential muscle soreness reduction.

Containing 110 mg of sodium and 172 mg of chloride, it helps replenish electrolytes. NSF-Certified for Sport ensures no banned substances are present. Despite some reports of an artificial taste, the powder mixes well with water or juice.

Glutamine

Best Budget Supplement: MusclePharm Glutamine

• $25 at Amazon
  • Pros:
    • Unflavored
    • Informed Choice certified
  • Cons:
    • Comes in a resealable bag that can be hard to close when the powder gets in the way

“L-glutamine supports gut integrity and reduces pro-inflammatory pathways,” notes Ibarra. Whether easing sore muscles, boosting immunity, or maintaining gut health, MusclePharm Glutamine offers 5 grams per serving at a budget-friendly price. It mixes well with water or protein powder and is Informed Choice Certified, ensuring quality and safety.

Glutamine

Klean Glutamine

• $58 at kleanathlete.com
  • Pros:
    • Free from artificial flavors, sweeteners, and colors
    • Single ingredient
  • Cons:
    • No subscription option

Klean Glutamine offers ninety 5-gram servings of pure L-glutamine, free from artificial additives. As an NSF-Certified for Sport supplement, it ensures no banned substances, mixing well with other supplements for muscle repair and recovery.