Leucine is an essential branched-chain amino acid (BCAA) that plays a critical role in protein synthesis, energy metabolism, and muscle repair. As a versatile BCAA, leucine and its derivatives are widely utilized in various industries due to their unique properties. In the pharmaceutical sector, they serve as key intermediates for drug development. In the food industry, leucine derivatives enhance taste and texture while providing nutritional benefits. Moreover, leucine is pivotal in wound healing, immune function support, and promoting muscle growth when consumed through dietary supplements or functional foods. Its derivatives further expand its applications by improving stability, solubility, and bioavailability. Due to their health-promoting attributes, these compounds are increasingly incorporated into sports nutrition products, medical formulations, and cosmetics for skin care.