Product Overview

L-Glutamine is the most abundant free amino acid in the human body, accounting for approximately 20% of the circulating free amino acid pool and over 60% of the free amino acid pool in skeletal muscle . As a conditionally essential amino acid, it is synthesized endogenously in sufficient quantities under normal physiological conditions. However, during periods of metabolic stress—such as illness, injury, surgery, sepsis, or intense physical exercise—tissue demand for glutamine exceeds the body's capacity to produce it, making dietary or supplemental intake critical for maintaining immune function and supporting recovery .

L-Glutamine plays a fundamental role in nitrogen transport, serving as the principal carrier of nitrogen between tissues. It is also a key metabolic fuel for rapidly dividing cells, particularly enterocytes (intestinal cells) and lymphocytes (immune cells), which rely heavily on glutamine for energy production, proliferation, and function . Its role in maintaining intestinal barrier integrity has been well-documented, with glutamine supporting the tight junction proteins that prevent intestinal permeability .

At Henan Liyin Biotech, we supply high-purity L-Glutamine in the form of a white crystalline powder, with a minimum purity of ≥98.5% (typically 98.5–101.0%), compliant with USP, EP, and FCC standards. Our product is available in Feed Grade, Food Grade, and Supplement Grade to serve applications across animal nutrition, human food, dietary supplements, and personal care.

Why Choose Our L-Glutamine?

• Verified Purity: Assay ≥98.5% (by HPLC), with typical batch results meeting USP/EP/FCC specifications
• Multi-Standard Compliance: Meets USP, EP, and FCC specifications, providing global regulatory acceptance
• Excellent Solubility: Readily soluble in water (100 g/L at 20°C), facilitating easy incorporation into feed premixes, beverages, and supplement formulations 
• Complete Traceability: Each batch is accompanied by a comprehensive Certificate of Analysis (COA), including testing for purity, heavy metals, and microbiological contaminants
• Flexible Packaging: Available in packaging options from 1kg to bulk quantities to suit your production needs

Key Functional Properties

Gut Health & Intestinal Integrity

L-Glutamine serves as the primary energy fuel for enterocytes, the cells lining the intestinal tract. It plays a critical role in maintaining the structural integrity of the intestinal barrier by supporting the expression and localization of tight junction proteins (occludin, claudins, zonula occludens), which prevent paracellular passage of luminal antigens, toxins, and pathogens into the bloodstream . Over 50% of enterally administered glutamine is metabolized within the intestinal mucosa, making it a more efficient energy fuel for enterocytes than glucose (yielding 9 ATP per mole vs. 8 ATP per mole from glucose) .

Immune System Support

Glutamine is a crucial fuel source for immune cells, including lymphocytes, macrophages, and neutrophils. These cells demonstrate high rates of glutaminase activity, and accelerated glutamine utilization has been reported to be greater than glucose uptake . Through glutaminolysis, glutamine supports cellular metabolism, purine and pyrimidine synthesis for cell proliferation, and the induction of protein transcription factors that regulate immune function .

Muscle Recovery & Exercise Performance

As the most abundant amino acid in skeletal muscle, glutamine plays a central role in muscle protein synthesis, glycogen replenishment, and post-exercise recovery. During periods of high-intensity exercise or physical stress, plasma glutamine levels can decline by 16–20% during recovery, supporting the rationale for glutamine supplementation in sports nutrition . Evidence suggests that glutamine may help reduce muscle soreness after high-intensity exercise .

Antioxidant Support & Cellular Protection

L-Glutamine serves as a precursor for glutathione synthesis, one of the body's most important endogenous antioxidants. Through its role in the Nrf2 pathway, glutamine supports the body's defense against oxidative stress . During heat stress and other conditions of physical stress, glutamine supplementation helps protect tissues from oxidative damage, reduce inflammation, and support hydration .

Stress & Recovery

Under conditions of metabolic stress (including severe burns, major surgery, sepsis, and exhaustive exercise), glutamine is considered conditionally essential. Circulating glutamine levels drop significantly during these periods, and supplementation can help restore plasma glutamine levels and support immune function and tissue repair

Quality Assurance & Documentation

All batches undergo rigorous quality control, including:

Assay by HPLC: ≥98.5% (typical results 98.5–101.0%)

Heavy Metal Screening: Lead, arsenic, and other contaminants

Microbiological Testing: Salmonella negative, Enterobacteriaceae ≤ 100 CFU/g

Specific Rotation and pH: Verified against USP/EP/FCC specifications

Loss on Drying and Residue on Ignition: To ensure stability and purity

We provide complete documentation with every shipment, including Certificate of Analysis (COA), Material Safety Data Sheet (MSDS), and Allergen Statement. Our GMP-certified production ensures batch-to-batch consistency and traceability.

Sourcing Support

We offer flexible packaging and can provide samples for pre-shipment testing. Our technical team is available to assist with grade selection (Feed, Food, or Supplement Grade), application guidance, and custom formulation support — from R&D trials to full-scale commercial production.

Contact us to discuss your specific L-Glutamine requirements or to request samples for your formulations.

L-Glutamine is the most abundant amino acid in the body, serving as a primary fuel source for immune cells and intestinal cells. It supports gut barrier integrity, immune function, and muscle recovery, particularly during periods of metabolic stress. Available in Feed, Food, and Supplement Grades with ≥98.5% purity.

Animal Feed

In animal nutrition, L-Glutamine is increasingly valued as a functional feed additive that supports gut health, immune function, and growth performance. Research has demonstrated that glutamine supplementation in weaned piglets can improve growth performance, serum biochemistry, redox status, and alter fecal microbiota . However, a 2025 study in Translational Animal Science found that supplementing liquid creep feed with 10 g/kg L-glutamine in suckling piglets from day 8 of age tended to reduce pre-weaning growth and increase diarrhea prevalence, highlighting the importance of species-specific and production-stage-specific formulation .

Key Applications:

• Weaned Piglets: Supports gut health and intestinal barrier function during the critical post-weaning period 
• Poultry: Supports immune function and gut integrity during periods of stress
• Aquaculture: Supports growth performance and stress resilience in fish and shrimp
• Pet Nutrition: Supports digestive health and immune function in companion animals

Recommended Inclusion: Levels vary by species and production stage. Our Feed Grade L-Glutamine is formulated for optimal dispersion in premixes and pelleted feeds.

Food & Beverage

L-Glutamine is widely used in the food industry as a nutritional supplement and flavor enhancer. It is recognized as a food additive with CAS 56-85-9 and is used in various food applications including dairy products, meat products, baked goods, and beverages .

Key Applications:

• Nutritional Fortification: Used to enrich dairy products, meat products, baked goods, and beverages 
• Flavor Enhancement: Functions as a flavor enhancer and can mask undesirable tastes in food products
• Functional Foods: Increasingly incorporated into health-focused food products targeting gut health, immune support, and recovery
• Sports Nutrition: Used in protein-based products and recovery beverages

Regulatory Status: FCC grade is suitable for food, beverage, and nutritional supplement applications. L-Glutamine is recognized as generally safe for use in food and beverages.

 Dietary Supplements

L-Glutamine is a popular ingredient in supplements targeting gut health, immune support, muscle recovery, and overall wellness. Its benefits are supported by a growing body of scientific research.

Gut Health & Digestion

• Supports the intestinal barrier and may help maintain gut health, particularly in individuals with inflammatory bowel disease (IBD) 
• As a major fuel for enterocytes, it helps protect the intestines from damage 

Immune Support

• Glutamine is a crucial fuel source for white blood cells, helping protect against infections 
• May help support immune function during periods of illness or stress 

Muscle Recovery & Sports Performance

• May help reduce muscle soreness after high-intensity exercise 
• Supports glycogen replenishment and muscle protein synthesis
• Typical dosages range from 5g to 20g per day, depending on intended use

Stress & Recovery

• Helps restore plasma glutamine levels during periods of metabolic stress 
• May support tissue repair and recovery following major surgery, burns, or injury 

Typical Dosage: Supplementation levels vary by intended use. Generally recognized as safe when taken as directed.

Personal Care & Cosmetics

L-Glutamine is used in personal care formulations for its skin-conditioning and moisturizing properties.

Skin Care

• Supports skin health through its role in cellular metabolism and antioxidant protection
• Used in moisturizers, serums, and anti-aging formulations
• Has been shown to be effective in protecting the skin from environmental stress

Hair Care

• Used in hair conditioning products to support hair health and strength

Formula Compatibility: Stable in topical formulations and compatible with a wide range of cosmetic ingredients .