Creatine monohydrate is a dietary supplement that is commonly used to improve exercise performance and increase muscle mass. It is a naturally occurring substance found in muscle cells and is involved in making energy for muscles. Creatine monohydrate helps create a steady supply of energy in muscles, especially during exercise, by converting adenosine diphosphate (ADP) back to adenosine triphosphate (ATP) via donation of phosphate groups. ATP is a source of energy that cells use when exercising, so creatine helps maintain a continuous energy supply to muscles during intense lifting or exercise.

Creatine monohydrate is the most common form of creatine supplement and is supported by hundreds of studies. It is very cheap and has been used and studied for decades. Other forms of creatine do not appear to have the same benefits as creatine monohydrate. Creatine supplements are not recommended for children or teens, and adults should consult with a healthcare provider to ensure they are right for them.

In addition to providing more energy and helping to increase muscle growth, creatine monohydrate may also promote brain health and support quality of life in older adults. Vegetarians, who may not obtain enough creatine from their diet, may find supplementing particularly useful.