L-Glutamine
L-Glutamine
The most abundant amino acid in the body, supporting gut health, immune function, and muscle recovery.
L-Glutamine is a conditionally essential amino acid that becomes crucial during stress, illness, or intense training. It's the primary fuel source for intestinal cells and immune cells. Supplementation is most beneficial during periods of high physical stress, gut issues, or immune challenges. Healthy individuals on adequate protein may not need it.
Mechanisms of Action
Intestinal Fuel
Primary energy source for gut cells
Immune Cell Support
Fuels rapidly dividing immune cells
Nitrogen Transport
Carries nitrogen between tissues
Recommended Dose
5-10g
Optimal Timing
- Post-workout
- Before bed
- Or split throughout day
Can be taken without food
Best Form
L-Glutamine powder
Alternatives: Capsules (but need many for effective dose)
Powder is most practical due to large doses needed. Tasteless and mixes easily.
Duration
Minimum: 2 weeks
Optimal: 4 weeks
Cycling: Not required
Note: Can be taken with or without food. For gut health, some prefer taking on empty stomach. Split doses may be easier on digestion.
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Improved Gut Health
Supports intestinal lining integrity
Immune Support
May reduce infection risk during heavy training
Enhanced Recovery
May reduce soreness after intense exercise
Likely safe at moderate doses; consult doctor
Consult oncologist; glutamine feeding of tumors is debated
Who Should NOT Take This
- Liver disease (impaired glutamine metabolism)
- Reye's syndrome
- Sensitivity to MSG (glutamine converts to glutamate)
Drug Interactions
May reduce lactulose effectiveness
May affect seizure control in some
Possible Side Effects
Tip: Start with lower dose
Tip: Split doses throughout day
Warnings
- Benefits may be minimal if already consuming adequate protein
- Most beneficial during illness, stress, or intense training
Probiotics
complementaryGlutamine supports gut lining while probiotics improve microbiome
Comprehensive gut health support
Zinc
complementaryBoth support gut barrier function
Enhanced intestinal integrity
Butyrate
complementaryBoth support gut lining
Enhanced gut healing
Colostrum
complementaryBoth support gut barrier integrity
Enhanced gut healing
DGL Licorice
complementaryBoth support gut lining integrity
Enhanced gut healing
Slippery Elm
complementarySlippery elm coats; glutamine feeds gut cells
Comprehensive gut repair
Zinc Carnosine
complementaryBoth support gut barrier integrity
Enhanced gut healing and barrier repair
Top studies from 40+ peer-reviewed papers
Liang S et al. • Cellular and molecular life sciences : CMLS (2022)
“The Author(s), under exclusive licence to Springer Nature Switzerland AG.”
Key Findings:
- By contrast, elevated L-glutamine degradation, and reduced L-glutamate and L-isoleucine biosynthesis were identified in depressive-associated microbiomes.
- After systemically reviewing the data of these collected cohorts, we have established a bacterial classifier to identify depressive symptoms with AUC 0.834 and 0.685 in the training and external validation dataset, respectively.
- Moreover, a low-risk bacterial cluster for depressive symptoms was identified, which was represented by a lower abundance of Escherichia-Shigella, and a higher abundance of Faecalibacterium, Oscillospiraceae UCG 002, Ruminococcus, and Christensenellaceae R.7 group.© 2022.
- The Author(s), under exclusive licence to Springer Nature Switzerland AG.
Hou XW et al. • Investigative ophthalmology & visual science (2021)
“This review summarizes potential biomarkers and metabolic pathways, providing insights into new pathogenic pathways for this microvascular complication of diabetes.”
Key Findings:
- This review summarizes potential biomarkers and metabolic pathways, providing insights into new pathogenic pathways for this microvascular complication of diabetes.
- Published in Investigative ophthalmology & visual science (2021)
- Further research warranted to confirm findings
Stehle P et al. • Critical Care Medicine (2020)
“Parenteral glutamine supplementation reduced infectious complications and hospital length of stay in ICU patients.”
Key Findings:
- Parenteral glutamine reduced infectious complications in ICU patients
- Significant reduction in hospital length of stay
- Enteral glutamine showed less consistent benefits than parenteral
Thom H et al. • BMJ open (2020)
“This NMA provides preliminary evidence comparing the efficacy of crizanlizumab with other treatments for VOC prevention.”
Key Findings:
- This NMA provides preliminary evidence comparing the efficacy of crizanlizumab with other treatments for VOC prevention.
- Published in BMJ open (2020)
- Further research warranted to confirm findings
Niihara Y et al. • The New England journal of medicine (2018)
“Among children and adults with sickle cell anemia, the median number of pain crises over 48 weeks was lower among those who received oral therapy with l-glutamine, administered alone or with hydroxyurea, than among those who received placebo, with or without hydroxyurea. (Funded by Emmaus Medical; ClinicalTrials.gov number, NCT01179217 .).”
Key Findings:
- A total of 230 patients (age range, 5 to 58 years; 53.9% female) were randomly assigned, in a 2:1 ratio, to receive l-glutamine (152 patients) or placebo (78 patients).
- The patients in the l-glutamine group had significantly fewer pain crises than those in the placebo group (P=0.005), with a median of 3.0 in the l-glutamine group and 4.0 in the placebo group.
- Fewer hospitalizations occurred in the l-glutamine group than in the placebo group (P=0.005), with a median of 2.0 in the l-glutamine group and 3.0 in the placebo group.
Study Type Distribution
Goals This Supplement Supports
Related Goals
This information is for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider before starting any supplement.