L-Glutamine
Of 2,904 on-market l-glutamine products in the January 2026 DSLD dump, the median declared dose is 1,000 mg, and 91.9% list unspecified/undisclosed form as the primary form.
Form share
Of 2,836 products with an identifiable primary form, here is the share held by each form of L-Glutamine on the market today.
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| Form | Quality tier | n | Share |
|---|---|---|---|
| unspecified/undisclosed form | Unrated | 2,605 | 91.9% |
| L-Glutamine Hydrochloride | Unrated | 83 | 2.9% |
| L-Alanyl-L-Glutamine (dipeptide) | Unrated | 66 | 2.3% |
| Glutamine Alpha-Ketoglutarate | Unrated | 47 | 1.7% |
| Glutamine Peptides (protein hydrolysate) | Unrated | 18 | 0.6% |
| N-Acetyl-L-Glutamine | Unrated | 17 | 0.6% |
Form share over time
Entry-year breakdown of the top forms, 2012–2025.
Dose distribution
Deciles of declared dose per serving (mg), among 1,760 products with a disclosed amount.
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- 70.9% of products fall below the fairy-dust threshold (3000 mg, 20% of the studied low dose).
- 37.9% of products don't disclose an amount because L-Glutamine is declared inside a proprietary blend.
Where does your dose rank?
Enter a per-serving dose (mg) to see exactly how it compares to the 1,760 on-market l-glutamine products with a disclosed amount. The chart above groups doses into deciles; this looks up the exact percentile for one number.
By dosage form
By target group
Top brands
Search interest over time
How often people search for l-glutamine on Google, US only, the last 5 years. This is public interest, not DSLD label data — a spike here doesn't necessarily line up with anything on this page, and Google's own index (100 = that term's peak popularity in the chosen window) is relative, not an absolute search-volume count.
Or see this search directly on trends.google.com.
Forms explained
Label discloses only "Glutamine" with no salt or source form.
Elemental fraction: 80.0% (C5H10N2O3 x HCl, 1:1 (glutamine 146.15 / 182.61))
Same amino acid delivered as a salt; no human study comparing glutamine HCl with free glutamine was located.
Elemental fraction: 67.3% (C8H15N3O4, MW 217.22 (glutamine 146.15 / 217.22))
Marketed for solubility and stability; the cited trial tested acute dipeptide ingestion during hydration stress in endurance exercise but not against free glutamine. No head-to-head human bioavailability or efficacy comparison of this form was located in PubMed searches.
Source: Hoffman JR et al. 2010, J Int Soc Sports Nutr 7:8, PMID 20181080
No head-to-head human bioavailability or efficacy comparison of this form was located in PubMed searches.
No head-to-head human bioavailability or efficacy comparison of this form was located in PubMed searches.
No head-to-head human bioavailability or efficacy comparison of this form was located in PubMed searches.
Reference values
- RDA (adult): not established — Conditionally essential amino acid; no RDA/AI exists.
- Tolerable Upper Intake Level (adult): not established — No UL established. Shao A, Hathcock JN 2008, Regul Toxicol Pharmacol 50(3):376-99, PMID 18325648: Observed Safe Level (not a UL) of 14g/day supplemental glutamine for healthy adults. Gleeson M 2008, J Nutr 138(10):2045S-2049S, PMID 18806122: acute intakes of ~20-30g without ill effect; no harm in one study of 28g/day for 14 days; up to 0.65g/kg tolerated by patients.
- Studied clinical dose range: 15000–15000 mg
- Zhou Q et al. 2019, Gut 68(6):996-1002, PMID 30108163 -- double-blind placebo-controlled RCT, 106 adults (54 glutamine, 52 placebo completed) with post-infectious IBS-D, glutamine 5g three times daily (15g/day) x8 weeks; IBS-SS responder rate 79.6% with glutamine, intestinal hyperpermeability normalized, adverse events similar to placebo. Pharmaceutical-grade L-glutamine was also tested at 0.3g/kg per dose twice daily in sickle cell disease (Niihara Y et al. 2018, NEJM 379(3):226-235, PMID 30021096; 230 patients; fewer pain crises) -- a weight-based clinical dose, not used for the range. A 2019 meta-analysis of athlete trials found no overall effect on aerobic performance, body composition or immune measures, apart from some weight reduction (Ramezani Ahmadi A et al., Clin Nutr 38(3):1076-1091, PMID 29784526).
- Note: 15g/day is essentially both the studied low and high in the one dose-defined RCT used; this reflects a narrow dose-defined evidence base for supplement use, not a gap in this file. Dipeptides (L-alanyl-L-glutamine), glutamine peptides and N-acetyl-L-glutamine are forms or related compounds -- see forms.yaml. Rows such as 'Glutamine peptides' declare a protein hydrolysate, not free glutamine.