L-glutamine supplements
L-glutamine isn't graded. The ISSN's 2018 review lists glutamine among supplements with little to no evidence of working, for building muscle and for performance. We still show each label's amount and directions, so you can see what you'd be taking.
Powders (13)
| Product | Per serving | Servings a day | Per day, as directed | Verdict | Proof |
|---|---|---|---|---|---|
| BulkSupplements.com L-Glutamine Powder · label 20 Jun 2024 | 5 g in one serving | 1 serving | 5 g | Not graded | Label claim only |
| Doctor's Best Pure L-Glutamine Powder · label 14 Dec 2023 | 5 g in 1 scoop (5 g) | 1 serving | 5 g | Not graded | Label claim only |
| Kaged Glutamine · label 23 Feb 2025 | 5 g in 1 scoop (5 g) | 3 servings | 15 g | Not graded | Label claim only |
| Klean Athlete Klean Glutamine · label 22 Nov 2024 | 5 g in 1 scoop (5.46 g) | 1 serving | 5 g | Not graded | NSF Certified for Sport, listed lots |
| Micro Ingredients Glutamine Powder · label 24 Sep 2021 | 3 g in 1 scoop (3 g) | 1 serving | 3 g | Not graded | Label claim only |
| Momentous L-Glutamine · label 23 Jan 2025 | 5 g in 1 scoop (5 g) | 1 serving | 5 g | Not graded | NSF Certified for Sport |
| MuscleTech Platinum 100% Glutamine · label 23 Jan 2015 | 5 g in 1 scoop (5 g) | 1–2 servings | 5–10 g | Not graded | Label claim only |
| NOW Sports L-Glutamine Powder · label 25 Jul 2024 | 5 g | 1–2 servings | 5–10 g | Not graded | Label claim only |
| NutraBio Glutamine · label 24 Apr 2025 | 5 g in 1 scoop (5 g) | 2–3 servings | 10–15 g | Not graded | Label claim only |
| Nutricost L-Glutamine Powder · label 24 Oct 2024 | 5 g in 1 scoop (5 g) | 1 serving | 5 g | Not graded | Label claim only |
| Optimum Nutrition Glutamine Powder · label 21 Jul 2022 | 5 g | 1 serving | 5 g | Not graded | Label claim only |
| Pure Encapsulations L-Glutamine Powder · label 23 Feb 2025 | 3 g in 1 scoop (3.1 g) | 1–3 servings | 3–9 g | Not graded | Label claim only |
| Sports Research L-Glutamine · label 11 Oct 2026 | 5 g in 1 scoop (5 g) | 1–2 servings | 5–10 g | Not graded | Label claim only |
Capsules (3)
| Product | Per serving | Servings a day | Per day, as directed | Verdict | Proof |
|---|---|---|---|---|---|
| Nutricost L-Glutamine 800 mg · label 22 Mar 2024 | 800 mg in 1 capsule | 1–3 servings | 800 mg–2.4 g | Not graded | Label claim only |
| Swanson L-Glutamine 500 mg · label 22 Mar 2024 | 500 mg in 1 capsule | 1–2 servings | 500 mg–1 g | Not graded | Label claim only |
| Thorne L-Glutamine · label 25 Sep 2025 | 500 mg in 1 capsule | 3 servings | 1.5 g | Not graded | Label claim only |
Tablets (1)
| Product | Per serving | Servings a day | Per day, as directed | Verdict | Proof |
|---|---|---|---|---|---|
| Jarrow Formulas L-Glutamine 1000 mg · label 22 Feb 2024 | 1 g in 1 tablet | 1–2 servings | 1–2 g | Not graded | Label claim only |
17 products. Where the directions give a range, the verdict judges the most they give in a day. Read the l-glutamine guide for the studies behind the dose. "Proof" is a published independent lab test, a certifier listing we read on the certifier's own site (usually for listed lots only), or "Label claim only" when we found neither.