L-glutamine is the most abundant amino acid in the human body, playing a pivotal role in various physiological processes. It serves as a primary fuel source for rapidly dividing cells, particularly those in the immune system and the lining of the gastrointestinal tract, aiding in the maintenance of gut integrity and supporting immune function. L-glutamine is also crucial for protein synthesis, nitrogen transport, and maintaining acid-base balance. Naturally found in protein-rich foods like meat, fish, dairy, and legumes, L-glutamine can be supplemented to support muscle recovery and reduce muscle breakdown, especially after intense exercise. Additionally, it has therapeutic applications in managing gastrointestinal conditions, such as leaky gut syndrome and inflammatory bowel diseases, by promoting intestinal health. Generally regarded as safe, L-glutamine supplements are available in various forms and dosages, providing a valuable tool for enhancing overall health and well-being when used responsibly.