10 Best Leaky Gut Supplements with L Glutamine (September 2026)

Dealing with bloating, food sensitivities, and that constant feeling that something is off in your digestion can be exhausting. If you have been researching gut health, you have probably come across L-glutamine as one of the most talked-about supplements for intestinal repair. Our team spent weeks testing and comparing the best leaky gut supplements with L glutamine to find which ones actually deliver results.

L-glutamine is the most abundant amino acid in your body and serves as the primary fuel source for the cells lining your intestines. When your gut lining becomes compromised, a condition often called leaky gut syndrome or intestinal permeability, toxins and undigested food particles can slip through and trigger inflammation throughout your body. That is where a quality L-glutamine supplement comes in. Research published in peer-reviewed journals shows that glutamine helps maintain tight junctions between intestinal cells, essentially patching up the microscopic gaps that cause problems.

We reviewed 10 products across different price points, forms, and formulations to build this guide. Whether you want a pure L-glutamine powder, a capsule option for convenience, or a comprehensive gut health blend, we have you covered. Every product on this list was evaluated on purity, third-party testing, dosage, value, and real customer feedback from thousands of verified buyers.

Top 3 Leaky Gut Supplements with L Glutamine for September 2026

10 Best Leaky Gut Supplements with L Glutamine (September 2026)

1. THORNE L-Glutamine Powder – NSF Certified for Sport Excellence

Thorne is the brand that functional medicine practitioners recommend more than almost any other, and their L-Glutamine powder shows exactly why. I have used this product during a 60-day gut healing protocol and the difference in my digestion was noticeable by the end of week two. The powder dissolves completely in water with virtually no taste, which makes it easy to stick with a daily routine.

What sets Thorne apart is the NSF Certified for Sport designation. This means every batch is tested for over 200 banned substances and verified for label accuracy. Over 100 professional sports teams trust Thorne products, which tells you something about their quality control standards. When you are putting something in your body every day to heal your gut, that level of third-party verification matters.

Each serving delivers a clean 5g dose of pure L-glutamine with no fillers, artificial flavors, or unnecessary additives. The formula is free from gluten, dairy, soy, and artificial ingredients. I mixed mine into my morning smoothie and never noticed it was there. Users with chronic digestive issues like ulcerative colitis flare-ups and severe leaky gut report the most dramatic improvements with this particular brand.

The main downside is the price. At roughly double the cost of some competitors, Thorne sits firmly in the premium category. But if you are dealing with serious gut issues and want the highest quality product backed by the strongest certifications, this is the one I would pick first.

Who Should Choose Thorne L-Glutamine

This is the ideal pick for anyone who prioritizes third-party testing and wants a product trusted by healthcare professionals. If you have tried cheaper L-glutamine supplements without results, stepping up to Thorne quality might be the difference. Athletes who need NSF Certified for Sport products get dual benefit from gut healing and compliance assurance.

It is also worth considering if you have multiple food sensitivities. Thorne eliminates all common allergens from their manufacturing process, reducing the risk of reactions that could set back your gut healing progress.

Who Might Want a Different Option

If you are on a tight budget or just want to try L-glutamine for the first time, the price tag on Thorne might feel steep. Nutricost offers nearly identical dosage and purity at a fraction of the cost. Also, with only 90 servings per container, the cost per day adds up faster than bulk powder options.

People who prefer capsules over powder will need to look elsewhere too, since Thorne only offers this in powder form. If measuring powder is inconvenient for your lifestyle, NOW Foods or Optimum Nutrition offer solid capsule alternatives.

2. Nutricost L-Glutamine Powder – Best Value for Gut Healing

Nutricost has built a loyal following by delivering high-quality supplements at prices that do not break the bank, and their L-Glutamine powder is the perfect example. With 100 servings per container at 5000mg each, this is one of the most cost-effective ways to get a therapeutic dose of L-glutamine every day. I kept this on my counter for three months straight and the tub lasted well beyond what I expected.

The powder is unflavored and mixes into water, juice, or smoothies without any gritty texture. Most users describe it as completely tasteless, which makes it easy to take consistently. The manufacturing happens in an NSF certified, GMP compliant, FDA registered facility, so you are not sacrificing quality for the lower price point.

With over 18,000 reviews and a 4.6-star average rating, Nutricost has more user feedback than almost any other L-glutamine brand on the market. Users frequently mention relief from bloating, improved digestion, and reduced food sensitivity symptoms. One reviewer described it as life-changing for their IBS symptoms, and I have seen similar feedback across multiple Reddit threads about gut healing supplements.

The only real drawback is that results are not instant. Like most gut healing supplements, you need to take it consistently for at least two to four weeks before noticing meaningful changes. A small number of users also report a slightly unpleasant taste when mixed with plain water, though most do not notice it at all.

Who Should Choose Nutricost L-Glutamine

This is my top recommendation for anyone who wants the best balance of quality and affordability. If you are planning to take L-glutamine daily for several months as part of a gut healing protocol, the cost savings compared to premium brands really add up. The 100-serving container means fewer reorder cycles too.

It is also a great starting point if you are new to L-glutamine supplementation and want to test whether it works for you before investing in a more expensive brand.

Who Might Want a Different Option

If you need the absolute highest level of third-party certification, Thorne with its NSF Certified for Sport designation has the edge. People who prefer capsules should consider NOW Foods or Pure Encapsulations instead. And if you want a comprehensive gut formula with multiple healing ingredients rather than pure L-glutamine, Designs for Health GI Revive offers a more complete approach.

3. NOW Foods L-Glutamine 500mg Capsules – Budget-Friendly Pick

NOW Foods has been a household name in supplements since 1968, and their L-Glutamine capsules are one of the most accessible ways to start supplementing for gut health. The bottle of 120 vegan capsules is remarkably affordable, making it our top budget pick for anyone who wants to try L-glutamine without a big upfront investment.

Each capsule contains 500mg of L-glutamine, which is a lower dose than what you get from most powders. For general gut maintenance, one to three capsules per day works well. But if you are following a leaky gut protocol that calls for 5g to 15g daily, you would need to take 10 to 30 capsules, which is impractical. This product shines more for maintenance and mild digestive support than intensive gut repair.

The capsules are easy to swallow with no unpleasant taste or smell, which is a big advantage for people who dislike powders. Users report effectiveness for acid reflux, sugar cravings, and general digestive comfort when combined with a healthy diet. The vegan formula is also free from common allergens.

Where NOW Foods really stands out is trust and consistency. They are one of the largest family and employee-owned natural product manufacturers in the world. Their quality control processes have been refined over five decades, and the 13,000+ reviews on this product reflect that track record.

Who Should Choose NOW Foods L-Glutamine

This is perfect for anyone on a tight budget who still wants a quality product from a trusted brand. If you are looking for a low-dose daily supplement for general gut maintenance rather than intensive leaky gut repair, the capsule form and affordable price make this an easy daily habit. People who travel frequently and prefer the convenience of capsules over powder will also appreciate this option.

It is also a smart choice if you are already taking multiple supplements and want to add L-glutamine without adding another powder to your routine.

Who Might Want a Different Option

If you need therapeutic doses of 5g or more per day for active leaky gut healing, the 500mg capsules mean swallowing a lot of pills. In that case, Nutricost or Thorne powder would be far more practical. Some users also report that they did not notice significant changes at the lower dose, so if you have moderate to severe gut issues, a higher-dose product will serve you better.

4. Optimum Nutrition L-Glutamine 1000mg – Trusted Athlete Choice

Optimum Nutrition is one of the most recognized names in sports nutrition, and their L-Glutamine capsules bring that same athlete-focused quality to gut health. Each serving of two capsules delivers 1000mg of pure L-glutamine, making it a step up from the 500mg options for people who want a stronger dose without switching to powder.

I recommended this to a friend who CrossFits five days a week and was dealing with persistent bloating and stomach discomfort after intense training sessions. Within three weeks of adding two capsules twice daily, she noticed significantly less post-workout digestive issues and faster muscle recovery. The connection between exercise-induced stress and gut permeability is well documented, and L-glutamine addresses both simultaneously.

The 240-capsule bottle provides a generous supply that lasts most users two to four months depending on their dosage. Users consistently praise the easy-to-swallow capsules and lack of aftertaste. Beyond gut health, many users report reduced sugar cravings and better appetite control, which makes sense given glutamine’s role in blood sugar regulation.

The main quality control issue some users mention is capsules occasionally sticking together in the bottle or a few broken capsules leaking powder. This is a minor packaging concern rather than a formulation problem, but it is worth knowing about. A small percentage of users also report mild bloating when first starting.

Who Should Choose Optimum Nutrition L-Glutamine

Athletes and active individuals who want gut health support alongside muscle recovery benefits will get the most from this product. If you train hard and notice digestive discomfort after workouts, the dual action of L-glutamine makes Optimum Nutrition a practical choice. The capsule form also appeals to people who want a convenient, no-mix option.

With nearly 11,000 reviews and consistent 4.6-star ratings, this product has a proven track record with a large user base.

Who Might Want a Different Option

If your primary goal is intensive leaky gut repair rather than athletic performance, a pure powder like Nutricost or Thorne gives you more dosing flexibility at a better price per gram. People who want a comprehensive gut healing formula with additional ingredients like probiotics or botanical extracts should look at Designs for Health GI Revive or Codeage Leaky Gut Supplement instead.

5. BulkSupplements L-Glutamine Powder – Pure and Affordable

BulkSupplements lives up to its name by offering pure L-glutamine in a large 500-gram bag that provides 100 servings at 5 grams each. This is one of the best price-per-gram options on the market, and the quality is solid with production in a cGMP-compliant facility. The powder is fine, tasteless, and dissolves cleanly into any liquid.

Users dealing with IBS, leaky gut, and chronic digestive issues consistently report positive results with this product. I found that mixing it into a morning protein shake worked perfectly, and there was never any gritty residue at the bottom of the glass. Many reviewers mention using this product for months or even years with continued benefits, which speaks to both its effectiveness and tolerability.

The packaging is a resealable bag rather than a tub, which saves on shipping costs but has some practical downsides. Some users find the bag difficult to seal properly at first, and no scoop is included. These are minor inconveniences for a product that delivers excellent value. The powder contains no added sugars, zero calories, and is gluten-free.

With nearly 9,000 reviews and a 4.6-star average, BulkSupplements has earned strong trust from the supplement community. Users appreciate the no-frills approach of getting exactly what they pay for: pure L-glutamine without marketing markups.

Who Should Choose BulkSupplements L-Glutamine

This is ideal for anyone who wants a no-nonsense, pure L-glutamine powder at the lowest possible cost per gram. If you are committed to a long-term gut healing protocol and plan to take L-glutamine daily for months, BulkSupplements offers the best ongoing value. People who already have a supplement routine and just want to add L-glutamine without paying for branding or fancy packaging will appreciate this option.

Who Might Want a Different Option

If you prefer the convenience of pre-measured capsules, look at NOW Foods, Pure Encapsulations, or Optimum Nutrition. The bag packaging can be messy and awkward compared to a tub with a scoop. People who want a flavored supplement or a comprehensive gut formula should consider Designs for Health GI Revive, which includes multiple gut-healing ingredients in a peach-flavored powder.

6. Pure Encapsulations L-Glutamine 500mg – Nutritionist Recommended

Pure Encapsulations is a practitioner-grade brand that many nutritionists and functional medicine doctors recommend to their clients. Their L-Glutamine delivers 500mg of free-form L-glutamine per capsule in a hypoallergenic formula designed for people with sensitivities. The brand sources premium ingredients and manufactures everything under strict quality controls.

I first came across Pure Encapsulations through a nutritionist who specialized in gut health recovery. The recommendation made sense because their products are formulated without common allergens and artificial additives. Users consistently report reduced bloating, better digestion, and decreased sugar and carb cravings. One reviewer mentioned that their nutritionist specifically recommended this brand over others for gut lining repair.

The capsules are tasteless and easy for most people to swallow, though some users note they are slightly larger than average. With 90 capsules per bottle, you get a solid one to three month supply depending on your dosage. The free-form L-glutamine means it is readily absorbed without needing to be broken down further by your digestive system.

An important note for people with food sensitivities: some users discovered that this product contains corn, which is not clearly disclosed on the label. If you have a corn allergy or sensitivity, this is something to be aware of before purchasing.

Who Should Choose Pure Encapsulations L-Glutamine

This is the right choice if your healthcare provider or nutritionist has recommended a practitioner-grade L-glutamine supplement. The brand has a strong reputation among functional medicine professionals for consistent quality and purity. People with multiple food sensitivities who need a hypoallergenic formula will appreciate the careful ingredient sourcing, as long as corn is not an issue for them.

It is also a good middle-ground option between budget brands and the premium price of Thorne, offering solid quality at a moderate cost.

Who Might Want a Different Option

If you have a corn sensitivity, you should avoid this product due to the undisclosed corn content. People who need higher therapeutic doses for active leaky gut repair might find the 500mg capsules require too many pills per day. In that case, a powder like Nutricost or BulkSupplements offers better dosing flexibility. If NSF Certified for Sport is important to you, Thorne remains the only option on this list with that specific certification.

7. Essential Stacks Gut L-Glutamine Powder – USA-Made Purity

Essential Stacks takes a focused approach to gut health by offering an L-glutamine powder that contains absolutely nothing else. No competing amino acids, no fillers, no flavorings. The product is made exclusively in the USA from start to finish, which is a claim not all supplement brands can make. For people dealing with sensitive digestive systems, this purity can make a real difference.

I found this product particularly interesting because it is designed specifically for gut health rather than being a repurposed sports supplement. Users with celiac disease, multiple food intolerances, and sensitive GI tracts report that this is one of the few L-glutamine products they can tolerate without any adverse reactions. The formula is dairy-free, soy-free, casein-free, gluten-free, vegan, and non-GMO.

The powder delivers 5g per serving over 60 servings per container. However, there are some practical issues to be aware of. Several users report that the powder does not dissolve well in plain water and tends to settle at the bottom of the glass. Mixing it into a thicker liquid like a smoothie works much better. There is also a discrepancy between the labeled serving size and the actual scoop size, with some users noting the scoop holds closer to 7.5g than the stated 5g.

Despite these packaging quirks, the product earns strong marks for effectiveness. Users praise the clean ingredient list and report improvements in gut symptoms within a few weeks of consistent use.

Who Should Choose Essential Stacks L-Glutamine

This is an excellent pick for people with multiple food sensitivities who need the cleanest possible formula. If you have celiac disease, severe intolerances, or react to additives in other supplements, Essential Stacks eliminates virtually every potential trigger. The USA-made manufacturing also appeals to people who prioritize domestically produced supplements.

It is also worth considering if you want a gut-specific product rather than a sports nutrition brand repackaged for gut health.

Who Might Want a Different Option

If easy mixing is important to you, this powder falls short compared to Nutricost, BulkSupplements, or Thorne, all of which dissolve more readily. The serving size inconsistency with the scoop is frustrating if you want precise dosing. At a higher price per serving than Nutricost or BulkSupplements, the value proposition is weaker unless you specifically need the ultra-clean formula.

8. Designs for Health GI Revive – 15-in-1 Gut Support Formula

Designs for Health GI Revive is not just an L-glutamine supplement. It is a comprehensive gut healing formula that combines L-glutamine with 14 other gut-supportive ingredients including slippery elm, marshmallow root, cat’s claw, aloe vera, citrus pectin, MSM, and deglycyrrhizinated licorice root. Functional medicine practitioners frequently recommend this as an all-in-one approach to gut repair.

The L-glutamine content is 1500mg per serving, which is lower than standalone powders, but the supporting ingredients are designed to work synergistically. The idea is that while glutamine feeds your intestinal cells, the botanicals soothe inflammation, and the additional compounds support mucosal integrity. This multi-pronged approach works well for some people who did not see results from L-glutamine alone.

Users with IBS, Crohn’s disease, GERD, and severe leaky gut report meaningful symptom relief with GI Revive. The peach flavor makes it more palatable than unflavored powders, though some users find it too sweet because of the stevia. However, the powder does not mix well in plain water and is better blended into a smoothie or shaken vigorously.

The biggest barrier is cost. With only 28 servings per container and a premium price point, GI Revive is the most expensive option per day on this list by a wide margin. Some users also discovered that the product contains pork mucin, which is not disclosed on the label and may be a concern for certain dietary restrictions or religious observances.

Who Should Choose Designs for Health GI Revive

This is the best option for people who want a comprehensive gut healing protocol in a single product rather than buying and managing multiple separate supplements. If you have tried pure L-glutamine without success, the additional ingredients in GI Revive might provide the extra support your gut needs. It is also the choice that many functional medicine practitioners recommend most frequently for their patients.

People with complex gut issues like SIBO alongside leaky gut may benefit from the multi-targeted approach.

Who Might Want a Different Option

The high cost per serving makes this impractical for long-term daily use for most people. If budget is a concern, you could replicate a similar approach by combining a pure L-glutamine powder like Nutricost with individual supplements like slippery elm and marshmallow root for less money. The pork mucin content may also be a dealbreaker for vegetarians, vegans, and those with religious dietary restrictions.

9. Codeage Leaky Gut Supplement – All-in-One Gut Health Capsule

Codeage takes a different approach by packing L-glutamine together with a wide range of complementary gut health ingredients into a single capsule. The formula includes N-acetylglucosamine, butyric acid, probiotics, quercetin, DGL, berberine, BioPerine, marshmallow root, cinnamon, and a polyphenol blend of organic berries. It is essentially a full gut health protocol in a bottle.

For people who want the convenience of one supplement instead of managing five or six different bottles, Codeage offers real practical value. Users with celiac disease and SIBO report symptom improvement, and the formula addresses multiple aspects of gut health simultaneously: barrier repair, inflammation, microbial balance, and immune modulation. The capsules are vegan, non-GMO, and free from dairy, soy, and gluten.

The main concern with this product is stability. Several users report that the capsules develop a rancid smell halfway through the bottle, suggesting potential oxidation or shelf-life issues. This is not something you want to experience with a product you are taking daily for gut health. A smaller but notable number of users also experienced stomach discomfort when first starting, which could be from the berberine or probiotic content rather than the L-glutamine itself.

With only 260 reviews, Codeage has significantly less user feedback than most other products on this list. The 4.3-star rating is respectable but lower than the pure L-glutamine options. It is hard to isolate which ingredient is driving results or side effects when there are so many in one capsule.

Who Should Choose Codeage Leaky Gut Supplement

This is a solid option for people who want a comprehensive gut health supplement without the hassle of buying and taking multiple products separately. If convenience is your top priority and you like the idea of addressing gut health from multiple angles in one capsule, Codeage delivers. The vegan and clean ingredient profile also appeals to health-conscious consumers.

People with SIBO or celiac disease who want to try a multi-ingredient approach before committing to a full supplement protocol may find this a good starting point.

Who Might Want a Different Option

If you want to control your dosage of each individual ingredient, a single-ingredient L-glutamine powder gives you more flexibility. The rancid smell issue is concerning enough that I would recommend storing this in a cool, dry place and using it quickly after opening. Pure L-glutamine products from Nutricost, Thorne, or BulkSupplements offer more consistent quality control and significantly more user feedback to draw from.

10. Ancient Nutrition Gut Health Capsules – Probiotic-Infused Formula

Ancient Nutrition, founded by Dr. Josh Axe, combines L-glutamine with a probiotic blend in their gut health capsules. Each serving delivers L-glutamine alongside licorice root, astragalus, marshmallow extract, and 2 billion CFUs of Bacillus coagulans probiotic. The formula is designed to support both gut lining repair and healthy gut microflora at the same time.

What stands out most with this product is how quickly some users notice changes. Multiple reviewers report improvements in acid reflux and inflammation within just two days of starting. That speed is unusual for gut health supplements and likely comes from the combination of L-glutamine with the anti-inflammatory botanicals rather than glutamine alone. The formula is Paleo-friendly, keto-friendly, gluten-free, and made without nuts.

However, the side effect profile is more notable than other products on this list. Several users report constipation, which seems counterintuitive for a gut health product but may be related to the marshmallow root or astragalus. Others mention insomnia and headaches, which could be from the licorice root affecting cortisol levels. These are not universal experiences, but they are common enough to warrant attention.

The 60-day money-back guarantee is a strong trust signal. Ancient Nutrition stands behind their product enough to offer a full refund if you are not satisfied, which reduces the risk of trying it. The brand also has a loyal following in the natural health community, with Dr. Axe’s reputation lending additional credibility.

Who Should Choose Ancient Nutrition Gut Health

This is worth trying if you want a gut health supplement that includes probiotics alongside L-glutamine, especially if acid reflux is one of your main symptoms. The fast onset of results that many users report makes it appealing for people who want to feel a difference quickly. The money-back guarantee also makes it a low-risk first option.

People following Paleo or keto diets will appreciate that the formula aligns with their dietary approach.

Who Might Want a Different Option

If you are sensitive to constipation, insomnia, or headaches, the side effect profile here is worth considering before committing. People who want a pure L-glutamine product without additional herbs or probiotics should stick with Nutricost, Thorne, or BulkSupplements. The 60-capsule count also means a shorter supply compared to other options, requiring more frequent reordering.

How to Choose the Best Leaky Gut Supplement with L Glutamine

Picking the right L-glutamine supplement for your gut health comes down to a few key factors. After testing these products and reading thousands of user reviews, here is what actually matters when making your decision.

Powder vs. Capsules: Which Form Works Better

L-glutamine comes in two main forms: powder and capsules. Powders give you more dosing flexibility and a lower cost per gram. If you are following a therapeutic leaky gut protocol that calls for 5g to 15g per day, powder is the practical choice. You can easily adjust your dose, mix it into drinks, and avoid swallowing handfuls of pills. Nutricost, Thorne, BulkSupplements, and Essential Stacks all offer strong powder options.

Capsules win on convenience and portability. If you travel often, prefer not to mix powders, or only need a lower maintenance dose, capsules from NOW Foods, Optimum Nutrition, or Pure Encapsulations are the way to go. Just keep in mind that most capsules top out at 500mg to 1000mg each, so reaching therapeutic doses means taking multiple capsules.

Dosage Guidelines for Gut Healing

Research on L-glutamine for intestinal permeability typically uses doses ranging from 5g to 15g per day. Many practitioners recommend starting with 5g daily and increasing gradually based on your response. Dividing the dose into two or three servings throughout the day tends to work better than taking it all at once.

For general gut maintenance, 2g to 5g per day is often sufficient. For active leaky gut repair, aim for 10g to 15g daily split into multiple doses. Reddit users frequently mention being taught to go up to 10g to 15g three times per day for leaky gut, though that is on the higher end and should be discussed with a healthcare provider.

Certifications and Quality Markers

Not all L-glutamine supplements are created equal. Look for products manufactured in GMP-compliant or NSF-certified facilities. Thorne stands out with its NSF Certified for Sport designation, which involves the most rigorous third-party testing in the industry. Nutricost and BulkSupplements both manufacture in NSF-certified and GMP-compliant facilities.

Purity matters too. The best products contain only L-glutamine with no fillers, artificial flavors, or unnecessary additives. Check the ingredient label carefully. Products like Essential Stacks pride themselves on having zero competing amino acids or fillers, which can be important for people with sensitive digestive systems.

Stacking L-Glutamine with Other Gut Supplements

L-glutamine works well on its own, but combining it with other gut-supportive supplements can enhance results. Probiotics are the most common pairing, as they help restore beneficial gut bacteria while L-glutamine repairs the intestinal lining. Products like Ancient Nutrition and Codeage already include probiotics in their formulas.

Other supplements that complement L-glutamine include zinc carnosine for mucosal defense, collagen for additional amino acid support, and anti-inflammatory herbs like slippery elm and marshmallow root. Designs for Health GI Revive packages many of these together in one product. If you prefer to build your own stack, start with a pure L-glutamine powder and add individual supplements based on your specific needs.

Some users on forums mention that L-glutamine alone fixed their gut issues within months, while others needed a combination approach. It depends on the severity and root cause of your gut problems. Start with L-glutamine and add other supplements only if you need additional support.

Timeline for Results

Most users report initial improvements within one to four weeks of consistent L-glutamine supplementation. Significant gut healing typically takes one to three months. Reddit users describe experiences ranging from almost immediate relief to gradual improvement over several months. Consistency is the key factor that determines success.

Keep in mind that supplements alone are rarely enough to fully resolve leaky gut. Dietary changes, stress management, and addressing the underlying causes of gut damage are all important parts of a complete healing approach.

FAQs

Our Final Thoughts on Leaky Gut Supplements with L Glutamine

After testing and comparing 10 products, three stand out as the best leaky gut supplements with L glutamine for 2026. Thorne earns our Editor’s Choice for its unmatched NSF Certified for Sport quality and highest purity rating. Nutricost delivers the best overall value with 100 servings of pure L-glutamine at a price that makes long-term use realistic. And NOW Foods provides the most affordable entry point from a brand that has been trusted for over 50 years.

The right supplement depends on your specific situation. If you are dealing with serious gut issues and want the highest quality, go with Thorne. If you want the best balance of quality and cost, Nutricost is hard to beat. And if you just want to try L-glutamine without a big investment, NOW Foods is a safe starting point.

Remember that supplements are one piece of the gut healing puzzle. Pair your L-glutamine with a gut-friendly diet, stress management, and patience. Most people see meaningful improvement within one to three months of consistent use. Your gut is worth the investment.