👉 Creatinine is a protein in the urine that helps to regulate the body's fluid balance by helping to transport waste products and excess fluids. It's primarily found in the kidneys, which are responsible for filtering waste from the blood. Creatinine levels can vary widely depending on the individual, but generally, normal creatinine levels range between 1.2-3.0 mg/dL (millimoles per liter of blood) in healthy adults and individuals with kidney disease may have higher than normal levels