Creatinine, or creatine anhydride, is the end product of muscle metabolism via irreversible dehydration of phosphocreatine in humans. As a key medical biomarker, its level variations accurately reflect renal function status.
In pharmaceuticals, though not a direct therapy, it serves dual roles: a critical raw material for drug R&D and a quality control indicator. Monitoring creatinine levels is essential to assess efficacy in developing drugs for renal function improvement or metabolic regulation, while its stable presence in compound formulations maintains system balance and ensures pharmaceutical quality. 
In food industry, it has multifunctional uses: nutritionally, participating in energy metabolism to rapidly supply energy during muscle contractions, making it a common additive in sports nutrition products to enhance athletes' endurance; as a flavor enhancer, it imparts rich, mellow taste to foods, widely used in meat products and soups processing for flavor enhancement.