L-Glutamine

Effects and Benefits

Core Identification

Common Names:
- L-Glutamine
- Glutamine
- L-Gln
- Gln

Latin Name: Not applicable (synthetic amino acid compound)

Category: Amino Acid

Uses

Traditional Uses

• Muscle recovery and athletic performance support - Used by athletes since the 1980s
• Gut healing and digestive support - Traditional use in clinical nutrition settings
• Recovery from illness, surgery, or injury - Long-standing use in hospital nutritional protocols

Modern Uses

• Intestinal Barrier Support (Leaky Gut) - Glutamine is the primary fuel source for enterocytes (intestinal lining cells) and helps maintain tight junction integrity | Research quality: Strong
• Key findings: Studies show glutamine can strengthen gut barrier function, reduce intestinal permeability, and support healing of the intestinal lining. Exercise-induced gastrointestinal permeability was reduced with glutamine supplementation.

• Source citations: Zuhl MN (2014) Journal of Applied Physiology; Brighten J - Beyond the Pill; Yates C - Optimum Health the Paleo Way

• Immune System Support - Glutamine serves as primary fuel for immune cells and helps maintain immune function during stress | Research quality: Strong

• Key findings: Taking 5g glutamine supplements reduced infection rates in athletes to less than 20% compared with greater than 50% infection rate in those not receiving glutamine. ICU patients receiving glutamine had significantly higher survival rates (57% vs 33%).

• Source citations: Brewer S - TDT Encyclopedia of Vitamins

• Muscle Recovery & Athletic Performance - Supports muscle tissue repair and glycogen replenishment after exercise | Research quality: Moderate

• Key findings: Blood glutamine levels drop 45-50% after intense exercise and may remain depressed for days. Supplementation (10-30g post-workout) may speed repair and help prevent soreness.

• Source citations: Ferriss T - The 4-Hour Body; Brewer S - TDT Encyclopedia of Vitamins

• Craving Reduction (Sugar & Alcohol) - May help reduce cravings for sugar and alcohol by affecting brain chemistry | Research quality: Moderate

• Key findings: Glutamine crosses the blood-brain barrier and may satisfy the body's craving for sugar and refined carbohydrates. Used in addiction treatment protocols since the 1980s.

• Source citations: Moline P - The Doctors Book of Natural Health Remedies; Mars B - The Country Almanac of Home Remedies

• Digestive Disorder Support - Used to help treat colitis, Crohn's disease, peptic ulcers, IBS, and diarrhea | Research quality: Moderate

• Key findings: May help reduce intestinal inflammation and support healing of damaged digestive tissue.

• Source citations: Brewer S - TDT Encyclopedia of Vitamins

• Chemotherapy Support - May reduce side effects of chemotherapy and radiation | Research quality: Moderate

• Key findings: Swishing and swallowing 4g glutamine liquid twice daily reduced mouth ulceration in chemotherapy patients. Supplementation reduced severity of drug-induced nerve damage and intestinal toxicity.
• Source citations: Gaby AR - A-Z Guide to Drug-Herb-Vitamin Interactions

Active Compounds

Primary Active Ingredients:
- L-Glutamine - The active amino acid form; primary fuel for enterocytes (intestinal cells) and immune cells
- Glutamic acid (precursor) - Can be converted to glutamine in the body; found in grains, grapes, nuts, and chocolate

Dosage Information

Standard Dosage:
- Form: Powder or capsules
- Amount: 500 mg to 5 g per day
- Frequency: Once to three times daily

Therapeutic Dosage:
- Form: Powder (most practical for higher doses)
- Gut healing: 1.5 to 5 g, two to three times daily (total 5-15 g/day) for 30-90 days
- Athletic recovery: 2-3 g post-workout, or 10-30 g post-workout for enhanced recovery
- Craving reduction: 500 mg four times daily between meals and at bedtime
- Intensive loading (short-term): Up to 80 g/day for 5 days (10 g every 2 hours), followed by lower maintenance doses
- Duration: 30-90 days for gut healing; ongoing for maintenance

Maximum Safe Dosage:
- Typical upper range: 30-40 g per day for most therapeutic purposes
- Loading protocols: Up to 80 g/day have been used short-term (5 days) under guidance
- Warning threshold: Use doses above 10 g/day with professional guidance

Bioavailability Notes:
- Powder mixed in water is most easily absorbed
- Best absorbed on empty stomach or between meals
- Heat destroys glutamine in food sources (raw meat, chicken, eggs are best dietary sources)
- Capsules are convenient but less practical for higher therapeutic doses

How to Take It

Timing:
- General supplementation: Between meals (2 hours before or after eating) for optimal absorption
- Athletic recovery: Within 30-60 minutes post-workout
- Craving control: Between meals and at bedtime
- Gut healing: Can be taken with or without food; some protocols recommend empty stomach

Synergies - What It Works Well With

Complementary Supplements:
1. Zinc - Both support intestinal cell development and gut healing | Combined effect: Enhanced gut barrier repair
2. Omega-3 Fatty Acids (EPA/DHA) - Both reduce inflammation | Combined effect: Comprehensive gut healing support
3. Probiotics - Glutamine feeds gut cells while probiotics support healthy microbiome | Combined effect: Complete digestive restoration
4. Vitamin A/Cod Liver Oil - Supports cell integrity and gut barrier | Combined effect: Enhanced mucosal healing
5. Glycine - Another amino acid for gut and tissue repair | Combined effect: Comprehensive tissue healing (both found in bone broth)
6. L-Arginine - Complementary amino acid for muscle and immune function | Combined effect: Enhanced anti-aging and muscle-building effects (suggested ratio: 2g glutamine to 1g arginine)
7. Curcumin & Quercetin - Anti-inflammatory compounds | Combined effect: Reduced intestinal inflammation

Avoidance - What NOT to Combine With

Supplement Interactions:
1. No significant negative supplement interactions documented - L-Glutamine is generally well-tolerated with other supplements

Drug Interactions:
1. Chemotherapy drugs (mixed) - While some studies show glutamine may enhance effectiveness and reduce side effects, others are inconclusive. Use only under oncologist supervision | Severity level: Moderate
2. Anti-seizure medications - Glutamine may theoretically affect seizure threshold; consult physician | Severity level: Moderate
3. Lactulose - Glutamine may reduce effectiveness of lactulose for hepatic encephalopathy | Severity level: Moderate

Food Interactions:
- No significant food interactions noted
- May be less effective when taken with large protein meals (competition for absorption)

Safety Information

Contraindications:
- Diabetes - Diabetics appear to have abnormal glutamine metabolism, with more glutamine being broken down for glucose production. Should not take except under medical advice.
- Chronic kidney disease or renal failure - Should avoid glutamine supplementation
- Hepatic encephalopathy - May worsen condition
- Sensitivity to MSG (monosodium glutamate) - Some individuals may react to glutamine

Side Effects:
- Common: Generally well-tolerated with few side effects at normal doses
- Possible at high doses: Mild gastrointestinal discomfort, bloating, nausea
- Rare: Headache, dizziness

Long-Term Use:
- Generally considered safe for extended use at moderate doses (up to 14g/day studied for 6 weeks)
- Individual amino acid supplements should not normally be taken for more than 12 weeks except under supervision of a doctor or nutritionist
- When using for more than 2 weeks, consider taking with a mixed amino acid complex to guard against amino acid imbalances
- Monitor kidney function if using high doses long-term

Special Precautions:
- Pregnancy/breastfeeding: Insufficient data; consult healthcare provider
- Pre-surgery: Generally considered safe and may support recovery, but inform surgeon
- Children: Dosing not well-established; use under medical supervision

Primary Uses At-a-Glance

Primary:
- Gut health and intestinal barrier repair (leaky gut)
- Immune system support
- Muscle recovery and athletic performance
- Sugar and alcohol craving reduction

Secondary:
- Digestive disorder support (IBS, colitis, Crohn's)
- Chemotherapy side effect reduction (under medical supervision)
- Post-surgical recovery support
- Weight management support (preserving lean muscle)

Sources

Local Library:
- Brewer, Sarah - TDT Encyclopedia of Vitamins
- Gaby, Alan R. - A-Z Guide to Drug-Herb-Vitamin Interactions 2nd Ed
- Ferriss, Timothy - The 4-Hour Body
- Yates, Claire - Optimum Health the Paleo Way
- Brighten, Jolene - Beyond the Pill
- Mars, Brigitte - The Home Reference to Holistic Health and Healing
- Mars, Brigitte - The Country Almanac of Home Remedies
- Moline, Peg - The Doctors Book of Natural Health Remedies
- Coffman, Sam - Herbal Medic
- Gehring, Abigail - The Illustrated Encyclopedia of Natural Remedies
- Pursell, J. J. - The Herbal Apothecary

General Knowledge:
- General amino acid biochemistry and clinical nutrition references
- Sports nutrition and exercise physiology literature