Amino Acid
L-Glutamine
Also known as: Glutamine, Gln, L-Glutamine (Wound Healing)
Most abundant amino acid in the body. Critical for gut lining integrity, immune function, and muscle recovery.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every L-Glutamine product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Thorne EnteroMend® | 93 A | $1.40 |
| 2 | Thorne Creatine + BCAAs | 92 A | $1.73 |
| 3 | Thorne L-Glutamine Powder | 92 A | $0.49 |
| 4 | Pure Encapsulations L-Glutamine powder | 92 A | $0.75 |
| 5 | Momentous L-Glutamine | 92 A | $0.67 |
| 6 | NutraBio Glutamine | 92 A | $0.30 |
| 7 | Kaged Glutamine | 91 A | $0.25 |
| 8 | Transparent Labs Post Workout Supplement | 90 A | $1.67 |
| 9 | Jarrow Formulas Neuro Optimizer | 87 A | $1.67 |
| 10 | Thorne MediClear-SGS™ - Vanilla | 86 A- | $2.10 |
| 11 | Pure Encapsulations Epi-Integrity powder | 85 A- | $2.00 |
| 12 | Bluebonnet Nutrition L-GLUTAMINE POWDER | 85 A- | $0.85 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much L-Glutamine should I take?
The typical range is 5-20 g daily in divided doses. Safe long-term
When should I take L-Glutamine?
Between meals or post-workout. Between meals often better.
Which form of L-Glutamine is best?
Powder — Economical for higher doses. Other forms in the catalog: Capsules.
Is L-Glutamine safe?
Commonly reported: Well tolerated. Serious warnings: Caution in cancer (theoretical). Caution severe liver disease
Which L-Glutamine supplement scores highest?
Thorne EnteroMend®, at 93/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Daily target & upper limit
5 g / dayL-Glutamine has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:
L-Glutamine dosage reference →Primary uses
- Gut health
- Muscle recovery
- Immune support
- Leaky gut
- Tissue repair
- Gut healing
- Burns
What systematic reviews concluded
Outcomes that systematic reviews of L-Glutamine reached a verdict on: 3 with a benefit, 1 with no effect. Each is quoted from a review and linked to it on PubMed. How these were read.
Reviews found a benefit (3)
“a reduction in postoperative complications was observed with combined immunonutrient supplementation (arginine, omega-3 fatty acids, nucleotides, L-alanine, and L-glutamine), particularly in wound infections” PMID 42023849
“This study identified that glutamine supplementation might have an important effect on CRP in acute conditions and no significant effect on IL-6 and TNF-α in acute conditions.” PMID 34213769
“One paper reported a suppressive effect of beta-hydroxy beta-methylbutyrate, L-arginine, and L-glutamine supplementation on muscle strength loss following TKR.” PMID 29941852
Reviews found no effect (1)
“no significant effect on IL-6 and TNF-α in acute conditions” PMID 34213769
3 findings from reviews in specific patient groups (such as cancer, pregnancy or surgery) are not shown here.
How it works
- Primary fuel for intestinal cells
- Supports gut barrier integrity
- Immune cell fuel
- Muscle protein synthesis
Dosage
- Typical range
- 5-20 g daily in divided doses
- Timing
- Between meals or post-workout
- With food
- Between meals often better
- Duration
- Safe long-term
- Special populations
- Gut issues, athletes, critical illness
Forms
- Powder
- Capsules
Safety
Common side effects
- Well tolerated
Contraindications
- Severe liver disease
- Some cancers (consult oncologist)
Products containing L-Glutamine
Top-scoring supplements in our catalog that list L-Glutamine on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Important for gut and muscle
Grade B: Some human trials support key claims; further confirmation needed.
Cited research for L-Glutamine
Clinical studies referenced across Formulate guides that mention l-glutamine. Each links to the full study page with PubMed source + the guides that cite it.
Related in Amino Acid
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.