Creatine is a nitrogenous organic acid that occurs naturally in vertebrates and helps to supply energy to all cells in the body, primarily muscle. This is achieved by increasing the formation of adenosine triphosphate (ATP). Creatine was identified in 1832 when Michel Eugene Chevreul discovered it as a component of skeletal muscle, which he later named after the Greek word for meat, kreas (kreas). In solution, creatine is in equilibrium with creatinine. Creatine is naturally produced in the human body from amino acids primarily in the kidney and liver. It is transported in the blood for use by muscles. Approximately 95% of the human body's total creatine is located in skeletal muscle. Creatine is not an essential nutrient, as it is manufactured in the human body from L-arginine, glycine, and L-methionine. In humans and animals, approximately half of stored creatine originates from food (mainly from meat).
Contributions by Yankees76, Karl Stas, and Edgar181.