Glutamine is a nonessential amino acid that could support muscle recovery, immunity, and gut health. When your body experiences physical stress or intense exercise, its natural glutamine production may not meet the increased demand.
In these cases, Glutamine supplements may help reduce muscle soreness, support digestion, and promote post-exercise recovery. They might also aid in the synthesis of other amino acids and help eliminate waste products like ammonia from your body.
In this article, we reviewed the top 10 glutamine supplements of 2025, evaluating them based on quality, effectiveness, and value so you can find the best option to support your goals.
NutraBio's Glutamine is derived from fermented vegetable-based ingredients, providing 5 grams of L-glutamine per serving (5g). It could aid in the removal of metabolic waste and help decrease muscle breakdown, which may contribute to increased strength and reduced soreness. The makers suggest consuming one level scoop (5g) of NutraBio Glutamine powder two to three times a day by mixing it in your preferred beverages.
Thorne's L-Glutamine Powder is an NSF Certified for Sport® formula that intends to support your muscle recovery, digestive health, and immune function. Each scoop (5.6g) provides 5 grams of L-glutamine, which may help replenish depleted glutamine levels.
L-Glutamine Powder by Thorne may help optimize recovery and support immune resilience after strenuous workouts. L-glutamine may also support nutrient absorption and gut health, thereby reducing the risk of digestive discomfort and food sensitivities.
Optimum Nutrition's Glutamine Powder contains 5g of L-glutamine per serving (5.15g). It could support faster recovery and tissue repair, which may improve athletic performance and support your training regimen.
Glutamine Powder by Optimum Nutrition provides unflavored, instantized L-glutamine, which you can easily add to water or your post-workout shake without affecting the taste.
Optimum Nutrition's Glutamine Powder may also support nitrogen balance, which is essential for preserving lean muscle mass during heavy training or calorie restriction. It also comes with a 30-day refund policy, provided you purchase it from the official Optimum Nutrition website.
Transparent Labs BCAA Glutamine delivers 8,000 mg of fermented BCAAs paired with 5,000 mg of L-glutamine per scoop (20.17g). It also contains 1,500 mg of vitamin C for antioxidant support and 1,000 mg of coconut water powder to assist with electrolyte balance.
As per the makers, Transparent Labs BCAA Glutamine avoids the use of artificial sweeteners, dyes, or fillers and uses only natural flavoring with stevia. Transparent Labs backs every batch of BCAA Glutamine with third-party testing with full access to lab test results.
Transparent Labs BCAA Glutamine comes in strawberry lemonade, blue raspberry, tropical punch, and sour green apple flavors.
Momentous L-Glutamine delivers 5 grams of L-glutamine per serving, which could support muscle maintenance by enhancing protein synthesis and minimizing muscle breakdown post-workout.
L-Glutamine by Momentous may also contribute to the synthesis of cellular energy, which could help fuel your workouts. L-glutamine may help reduce inflammation within the digestive tract and preserve the integrity of the gut lining. These benefits might help improve the body's natural defense mechanisms and boost immunity.
According to its official site, one scoop (5 grams) of Kaged Glutamine features 5 grams of glutamine made through a patented fermentation process. It could provide essential support for post-exercise recovery, tissue repair, and reduced muscle breakdown.
Kaged Glutamine could help stimulate muscle protein synthesis, a process that may support muscle growth and repair. It can also be cost-effective at just 25 cents per scoop, which may help optimize physical performance and reduce soreness.
Kaged Glutamine also provides a 60-day money-back guarantee, supporting hassle-free returns if it does not meet your expectations. The makers state that Kaged Glutamine can mix easily with any beverage, making it easy to include as pre-, intra-, or post-workout nutrition.
Revive Glutamine provides 10 grams of glutamine per 10-gram scoop. It could assist in maintaining nitrogen balance, support gut barrier health, and provide immune support. These benefits may help exercise-induced fatigue and improve recovery efficiency.
The makers state that Revive Glutamine could also help fuel lymphocytes, the white blood cells responsible for immune defense. Such effects may help protect your body against pathogens, thereby reducing the frequency of common infections and illnesses.
Type Zero L-Glutamine powder delivers 5,000mg of unflavored L-glutamine per 5g-serving. It could help accelerate muscle repair and growth, especially after high-intensity exercise when natural glutamine levels tend to drop.
L-Glutamine by Type Zero may also act as the primary source of energy for the cells that line the intestines. It may fuel the vital digestive processes, which could help maintain a healthy gastrointestinal environment.
As per the makers, Type Zero's L-Glutamine is free from allergens like sugar, soy, gluten, and artificial ingredients. It is produced in a GMP-certified facility in the USA, prioritizing premium glutamine supplementation.
L-Glutamine Powder by Bulk Supplements provides an unflavored formula, offering 5,000 mg of L-glutamine per serving (about 2 tsp). It could support the body's natural detoxification processes by clearing ammonia, a waste product of protein metabolism.
Bulk Supplements' L-Glutamine Powder may also support collagen synthesis and tissue repair. These processes might support faster wound healing, recovery from injuries, and skin health.
The makers suggest consuming Bulk Supplements' L-Glutamine Powder by mixing it into shakes, yogurt, oatmeal, or adding it to homemade energy bites.
The brand EHP Labs claims that its glutamine supports faster recovery from physical stress and intense training. Each scoop (5g) features 20 calories, 5 grams of L-glutamine, and 5 grams of protein. The product also undergoes HPLC (High-Performance Liquid Chromatography) testing to ensure consistent quality and potency in every batch.
EHP Labs' Glutamine may support cellular repair and help maintain the structure of the intestinal lining. These processes are beneficial for those experiencing digestive discomfort or strain, including people with IBS or IBD.
The makers suggest mixing 1-2 scoops of EHP Labs Glutamine with approximately 10 ounces (295 ml) of water and consuming it daily. However, they recommend not exceeding 3 scoops per day, which provides up to 15 grams of L-glutamine.
Your body metabolizes glutamine supplements and naturally produces ammonia, a compound that your liver typically converts into urea. If you have pre-existing liver or kidney impairments, your body's ability to clear ammonia may decrease, leading to a condition known as hyperammonemia. In mild cases, you might experience side effects like fatigue, irritability, nausea, or confusion. In more serious instances, elevated ammonia levels might impact brain function, potentially causing symptoms like disorientation, lethargy, or even coma.
Using glutamine supplements later in the day, such as in the evening, may cause disruptions in your sleep pattern. Your body converts glutamine from supplements into glutamate. It is an excitatory neurotransmitter that may stimulate brain activity and make it difficult for you to fall asleep or stay asleep. Increased glutamate levels may also trigger symptoms like insomnia, restlessness, or frequent awakenings.
You might experience mild stiffness or tightness in your muscles or joints when using glutamine supplements. These side effects may occur as glutamine draws water into muscle cells, causing temporary changes in cellular hydration and tissue feel.
In some cases, glutamine supplements may also trigger shifts in nitrogen balance or sensitivity to inactive ingredients. This may create a sensation of tightness, mild stiffness, or reduced flexibility in your muscles.
You might notice a metallic or unusual taste in your mouth after taking glutamine supplements, especially if you take them in powder form or on an empty stomach. The side effect typically results from glutamine's interactions with your taste receptors or minor changes in saliva chemistry. The raw taste of glutamine powder may linger in the mouth post-consumption.
Glutamine supplementation may trigger a sensation of head pressure or mild, tension-like headaches. The supplements may influence the synthesis of neurotransmitters like glutamate and GABA, causing fluctuations in their levels and neuronal excitability. This may contribute to temporary vascular changes or headaches, particularly if you are dehydrated or prone to migraines.
When selecting the best glutamine supplements for 2025, we looked into customer experiences on platforms like Trustpilot, complaint records and ratings from the Better Business Bureau (BBB), and the company's track record in the industry.
NutraBio leads with a Trustpilot rating of 4.9/5 based on 1050+ reviews, an A+ BBB rating, and a reputation for purity and transparency. Thorne has received a B rating on BBB and follows strict manufacturing standards, even though it lacks user reviews on Trustpilot.
Optimum Nutrition has some brand credibility and an A+ score on BBB, with a 2.4/5 Trustpilot rating. Transparent Labs is known for providing clean and premium supplements, although its D- rating on BBB from unanswered complaints may lower its trust factor.
Kaged remains unrated on Trustpilot and BBB. Similarly, Momentous claims to maintain professional-grade certifications but lacks a BBB rating.
Brands like Revive and Type Zero are unrated and relatively new, with limited track records. Bulk Supplements, under Hard Eight Nutrition LLC, has a low Trustpilot rating (1.8/5 based on 239+ reviews). It also has been BBB accredited since 2014 but holds a B rating, mainly due to 38 complaints filed over the past three years. This indicates a need for better complaint resolution.
EHP Labs ranks at the bottom, with an F rating from the BBB and unresolved consumer complaints that overshadow its credibility.
In evaluating the best glutamine supplements of 2025, price and value played a major role. We looked beyond just the cost per serving to assess how much glutamine you're getting for your money, considering the total price, number of servings, and brand quality.
Revive Glutamine offers the lowest total price at $19.99 but comes with only 30 servings, making it less cost-effective despite the low entry point. In contrast, Kaged and NutraBio offered standout value at $24.99 each for 100 servings, combining affordability with clean, trusted formulas.
Type Zero's L-Glutamine costs $25.25, and Bulk Supplements L-Glutamine Powder costs $25.97, both delivering 100 servings each. These brands also maintained strong reputations for purity, offering suitable glutamine options in the mid-tier.
Optimum Nutrition is priced slightly higher at $26.99 for 58 servings, delivering reasonable value. Meanwhile, EHP Labs and Momentous were both priced at $39.95, but EHP Labs offered nearly double the servings, making it the better deal.
Transparent Labs' BCAA Glutamine came in at $39.99 with just 30 servings. Its added BCAAs may justify the price for some users, but it's not the best pick for pure glutamine users. Thorne's L-Glutamine Powder was the most expensive at $63 for 90 servings. It may offer premium quality but is not ideal for consumers focused on affordability.
In evaluating the best glutamine supplements, we considered the returns and refund policies to ensure that consumers remain protected in case the product doesn't meet their expectations.
NutraBio's Performance Glutamine offers the most flexible return policy with a 90-day full refund or exchange. Transparent Labs – BCAA Glutamine provides a 45-day return window, offering a full refund or store credit on returns.
Thorne's L-Glutamine Powder allows returns within 60 days but requires processing through authorized resellers, which may be slightly less convenient. Kaged Glutamine offers a 60-day return period with options for a refund, store credit, or replacement, although customers are responsible for return shipping.
EHP Labs Glutamine requires returns to be unused and in original condition. Still, it doesn't specify a clear time limit, which may cause some confusion. Optimum Nutrition allows returns within 30 days for products that are at least 75% unused. Still, this policy is less accommodating for those who have partially used the product.
Type Zero's Clean L-Glutamine offers a 30-day return window but is limited to unused products with original packaging. On the other hand, Bulk Supplements' L-Glutamine Powder offers returns within 30 days but provides only a partial refund for opened items and requires customers to pay for return shipping.
Momentous L-Glutamine has a 30-day satisfaction guarantee, and the brand does not accept returns once the product has been delivered.
Meanwhile, Revive Glutamine has a restrictive 15-day return policy with a 15% restocking fee and refunds in the form of store credit, which limits its flexibility.
Glutamine supplements could help support gut health, reduce muscle breakdown during exercise, and promote immunity. They may help restore depleted glutamine levels and support the body's physiological processes when glutamine demand exceeds natural production.
The 10 glutamine supplements featured in this article are selected for their quality, clinical dosing (typically around 5 grams per serving), and transparency. However, current research suggests that glutamine supplementation offers the most benefit if you are under high physical stress or have increased metabolic demands.
Glutamine supplements are generally well-tolerated, but potential side effects may include mild digestive discomfort, a metallic aftertaste, sleep disturbances, or muscle stiffness. Overuse may raise blood ammonia levels, especially if you have pre-existing liver or kidney concerns.
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