Creatinine is a breakdown product formed by the degradation of creatine phosphate from muscles. The kidneys extract creatinine from the body by filtering almost all of it from the blood and excreting it in the urine. Serum creatinine is the most commonly used indicator for renal functioning. In chemical synthesis, creatinine is used as a heterocyclic nitrogenous compound that produces electron-rich and highly basic creatinine derivatives.
