👉 Creatine is a naturally occurring amino acid that plays an important role in muscle function and recovery. It is commonly used as a supplement to enhance athletic performance, including strength, endurance, and recovery time. Creatine can be found in sports drinks, protein powders, and supplements. The term "creatinine" refers to the chemical form of creatine, which is also known as citrulline. It is essential for the synthesis of creatine phosphate, a compound that is used by