Thorne · L-glutamine · Capsules
Is Thorne L-Glutamine underdosed?
1 serving = 1 capsuleDirections: 3 servings a dayLabel as of 25 Sep 2025 · NIH DSLD
Verdict
1.5 g a dayas the label directs
Not gradedContains 1.5 g. Not graded: the ISSN's 2018 review lists glutamine among supplements with little to no evidence of working, for building muscle and for performance.
One capsule gives 500 mg.
What the label says
- L-Glutamine per serving
- 500 mg in 1 capsule
- Servings a day
- 3 servings a day
- L-Glutamine a day, as directed
- 1.5 g
- Research dose
- Not graded Evidence: Not graded
Suggested use: Take 1 capsule three times daily or as recommended by your health-care practitioner.
More about l-glutamine: forms, timing and the studies behind the dose.
Same category, compared
All 17 L-glutamine supplements we checked, ranked by dose (commission never changes the order).
| Product | Per serving | Form |
|---|---|---|
| BulkSupplements.com L-Glutamine Powder | 5 g | Powders |
| Doctor's Best Pure L-Glutamine Powder | 5 g | Powders |
| Jarrow Formulas L-Glutamine 1000 mg | 1 g | Tablets |
| Kaged Glutamine | 5 g | Powders |
| Klean Athlete Klean Glutamine | 5 g | Powders |
| Micro Ingredients Glutamine Powder | 3 g | Powders |
| Momentous L-Glutamine | 5 g | Powders |
| MuscleTech Platinum 100% Glutamine | 5 g | Powders |
| NOW Sports L-Glutamine Powder | 5 g | Powders |
| NutraBio Glutamine | 5 g | Powders |
| Nutricost L-Glutamine 800 mg | 800 mg | Capsules |
| Nutricost L-Glutamine Powder | 5 g | Powders |
| Optimum Nutrition Glutamine Powder | 5 g | Powders |
| Pure Encapsulations L-Glutamine Powder | 3 g | Powders |
| Sports Research L-Glutamine | 5 g | Powders |
| Swanson L-Glutamine 500 mg | 500 mg | Capsules |
| Thorne L-Glutamine (this product) | 500 mg | Capsules |
Where the reference doses come from
- L-Glutamine, : .
- Label data: National Institutes of Health, Office of Dietary Supplements. Dietary Supplement Label Database, 2026. https://dsld.od.nih.gov/. Label 336343, including its servings a day.
For a supplement taken every day we judge the most the label's directions give in a day, and show the least. Read the full methodology or the corrections log.