Used as a nutritional supplement in animal feed, particularly for poultry and swine, to support growth and protein synthesis. Commonly added to plant-based diets that are deficient in lysine, an essential amino acid. Also utilized in pharmaceutical formulations to address lysine deficiency in humans. Employed in cell culture media as a building block for protein production. Serves as an excipient in some drug formulations to enhance stability. Widely used in the food industry to fortify products and improve amino acid profile.