Glutamine 4L Glutamine is the most abundant amino acid in muscle cells, making up over 60% of skeletal muscle. Among the 20 amino acids, glutamine is the most versatile, crucial for amino acid metabolism, immune function, and intestinal health. Often, the body's demand for glutamine surpasses its production capacity, highlighting the importance of adequate intake and supplementation. EHP Labs L Glutamine is HPLC tested to ensure the highest quality