Best L-Glutamine Supplements 2026: Cost per Effective Dose
Top pick for L-Glutamine: Naked Nutrition Pure L-Glutamine Powder (1 kg, 200 servings) — 5000mg L-glutamine per 1 scoop (5 g), None (3rd-party heavy-metal tested), $0.17/day. Our best-value pick.
All L-Glutamine Supplements Compared
All 13 products sorted by cost per labelled serving (lowest first). Dose, certification, and pricing verified against NIH DSLD and manufacturer data.
Read the dose column before the price column. Servings in this category are not equivalent — they range from 1,000 to 5,000 mg L-glutamine per serving. A lower cost per day here can simply mean a smaller serving, so the cheapest row is not automatically the best value.
| Product | Brand | Dose / Serving | Cost / Day | Certification | Pick | Buy |
|---|---|---|---|---|---|---|
| Horbaach L-Glutamine 1000 mg (180 Capsules) | Horbaach | 1000mg L-glutamine / 1 capsule (1 g) | $0.06 | None | Buy | |
| Optimum Nutrition L-Glutamine 1000 mg (240 Capsules) | Optimum Nutrition | 1000mg L-glutamine / 1 capsule (1 g) | $0.08 | None | Buy | |
| NOW Sports L-Glutamine 1000 mg (120 Veg Capsules) | NOW Foods | 1000mg L-glutamine / 1 capsule (1 g) | $0.12 | None (cGMP) | Buy | |
| Naked Nutrition Pure L-Glutamine Powder (1 kg, 200 servings) | Naked Nutrition | 5000mg L-glutamine / 1 scoop (5 g) | $0.17 | None (3rd-party heavy-metal tested) | Best Value | Buy |
| BulkSupplements L-Glutamine Powder (1 kg) | BulkSupplements | 5000mg L-glutamine / 1 scoop (5 g) | $0.18 | None (3rd-party tested) | Buy | |
| Nutricost L-Glutamine Powder (500 g) | Nutricost | 5000mg L-glutamine / 1 scoop (5 g) | $0.23 | None (3rd-party tested) | Buy | |
| Sports Research L-Glutamine Powder (500 g) | Sports Research | 5000mg L-glutamine / 1 scoop (5 g) | $0.25 | None (NOT NSF Certified for Sport despite sport branding) | Buy | |
| BulkSupplements L-Glutamine Powder (500 g) | BulkSupplements | 5000mg L-glutamine / 1 scoop (5 g) | $0.26 | None (3rd-party tested) | Buy | |
| NOW Sports L-Glutamine Pure Powder (1 lb) | NOW Foods | 5000mg L-glutamine / 1 rounded tsp (5 g) | $0.26 | None (cGMP) | Buy | |
| MRM L-Glutamine 5000 mg Powder (500 g) | MRM Nutrition | 5000mg L-glutamine / 1 scoop (5 g) | $0.27 | None | Buy | |
| Optimum Nutrition L-Glutamine Powder (1000 g) | Optimum Nutrition | 5000mg L-glutamine / 1 scoop (5 g) | $0.29 | None (NOT NSF Certified for Sport) | Buy | |
| Life Extension L-Glutamine Powder (100 g) | Life Extension | 2000mg L-glutamine / 1/2 tsp (2 g) | $0.33 | None | Buy | |
| Thorne L-Glutamine Powder (513 g, 90 servings) | Thorne | 5000mg L-glutamine / 1 scoop (5 g) | $0.74 | NSF Certified for Sport | Buy |
Our Picks
Best Value: Naked Nutrition Pure L-Glutamine Powder (1 kg, 200 servings)
5000mg L-glutamine per 1 scoop (5 g). None (3rd-party heavy-metal tested). $0.17/day. 200 servings per container at $34.99.
Naked Nutrition Pure L-Glutamine Powder (1 kg, 200 servings) →
How We Rank L-Glutamine Supplements
Every product is evaluated on three criteria:
- Cost per day. Not cost per pill or cost per bottle — what it actually costs per day at the product's labelled serving. Where a category's servings differ in strength we flag it above the table, because cost per day is only comparable when the doses are.
- Third-party certification. USP Verified, NSF Certified for Sport, and ConsumerLab Approved indicate independent testing for purity, potency, and contaminants.
- Bioavailable form. We prioritize products using the specific chemical form shown to be most effective in published research.
Rankings are not influenced by affiliate commissions. We earn the same commission regardless of which product you choose. Read our full methodology.
Personalize Your L-Glutamine Choice
Not sure which l-glutamine supplement is right for you? Use our free tools:
- DNA Supplement Analyzer — upload 23andMe or AncestryDNA data to check for genetic variants affecting l-glutamine metabolism. Runs entirely in your browser.
- Lab Results Interpreter — enter your blood test values to get personalized dosing recommendations.
- Supplement Stack Builder — build a complete protocol based on your age, sex, medications, and goals.
- Supplement Audit — already taking l-glutamine? Check if you have the right form and dose.