L-Glutamine Powder

Pure, Single-Ingredient Glutamine to Fuel the Gut Lining, Support Immune Function & Protect Lean Muscle

Glutamine is the most abundant amino acid in the body and one of the most important. It serves as the primary fuel source for the cells lining the small intestine, the immune cells that patrol the gut, and the fibroblasts responsible for building collagen throughout the body. Under normal circumstances, the body produces enough glutamine to meet its needs. Under stress, however, whether from illness, surgery, intense exercise, chronic gut dysfunction, or prolonged physiological demand, glutamine is rapidly depleted and the body's ability to synthesize it cannot keep pace. Klaire Labs delivers 5g of pure pharmaceutical-grade L-glutamine per scoop, with absolutely nothing else. No fillers, no flavors, no additives of any kind.

What L-Glutamine Supports

• Gut lining integrity: Glutamine is the preferred fuel for enterocytes, the cells that line the intestinal wall and form the barrier between the gut lumen and the bloodstream. Adequate glutamine supports healthy tight junctions, reduces intestinal permeability, and helps maintain the mucosal barrier that keeps pathogens and inflammatory triggers where they belong
• Immune function: Immune cells, particularly lymphocytes and macrophages, rely heavily on glutamine as a metabolic fuel. Glutamine depletion under stress is a major contributor to immune suppression, making supplementation particularly valuable during illness, recovery, and periods of high demand
• Lean muscle mass: Glutamine is highly concentrated in muscle tissue and plays a role in protein synthesis and nitrogen balance. It supports recovery after exercise and helps preserve lean muscle during periods of stress or caloric restriction
• Collagen production: Fibroblasts, the cells responsible for producing collagen in skin, connective tissue, and the gut lining itself, use glutamine as a primary energy source, making it foundational to tissue repair throughout the body
• Glutathione synthesis: Glutamine is a direct precursor to glutathione, the body's master antioxidant, supporting cellular detoxification and protection from oxidative stress

Why Single-Ingredient Matters

Most glutamine powders on the market include flavoring agents, sweeteners, or fillers that can be problematic for individuals with sensitive digestive systems, food sensitivities, or autoimmune conditions. Klaire Labs L-Glutamine Powder contains one ingredient and nothing else, making it the cleanest, most versatile option available. It is tasteless, dissolves completely in water or any beverage, and can be added to smoothies, food, or functional drink formulas without altering flavor.

Best For

Anyone working to support gut lining integrity, recover from a period of GI distress or antibiotic use, or maintain immune and mucosal health under physiological stress. Pairs well with GI Revive®, a probiotic, and a digestive enzyme for a comprehensive gut restoration protocol.

How to Use

Mix 1 scoop (approximately 5.85g, providing 5g L-glutamine) into water, juice, or food once to twice daily, or as directed by your healthcare provider. Children: as directed by a healthcare professional.

Consult your healthcare provider before use if you are pregnant, nursing, taking prescription medications, or managing a medical condition.

Clean Credentials

• Single ingredient: L-glutamine only
• No fillers, flavors, colors, or preservatives
• Free from all common allergens including milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, gluten, soy, and sesame
• Vegan and non-GMO

Supplement Facts (per 1 scoop, approx. 5.85g)

L-Glutamine: 5g

Other ingredients: None

Size: 12.38 oz (351g) powder, 60 servings