Creatine is naturally produced in the body from amino acids mainly in the liver and kidneys. Around 95% of the human body's total creatine is in skeletal muscle. A small portion of which is located in the heart and the brain. Creatine is produced in the human body from the amino acides L-arginine, glycine, and L-methionine.

Approximetly half of stored creatine originates from food (primarily from meat). As vegetables do not provide the body with creatine, vegetarians tend to have lower levels of muscle creatine, but these levels can be improved with the supplementation of creatine products.

Athletes take creatine to help them to gain muscle mass. Creatine comes in many forms eg: creatine monohydrate (creatine complexed with a molecule of water) such as USN Creatine, this being the most common form ,Creatine ethyl ester (CEE), such as CNP Pro Creatine E2, which is said to have a improved absorption rate, as well as Kre alkalyn, such as Kre-A-Fem, and creatine diphosphate, all of which have slightly different characteristics. Creatine supplements come in tablet and powder form as well as some companies now producing it in liquid form, when taking in its powdered monohydrate form it is recommended to be taken with high G.I. carbohydrates or simple sugars to improve absorption.

There is scientific evidence that short term creatine use can help increase maximum power and performance in high-intensity anaerobic work (periods of work and rest) from ranges of 5 to 15%. This is mainly bouts of short explosive exercises such as running/cycling sprints and multiple sets of low rep weightlifting.