Creatine is an acid produced in the liver that supplies some energy to muscle cells. It is typically found in vertebrates. The liver makes creatine out of three amino acids called arginine, glycine, and methionine. Most of the creatine the human body makes is then stored in the muscles that support the skeleton.

Creatine is often confused with creatinine. Creatinine is actually the broken down form of creatine that the kidneys process and dispose of. Normal measurement of creatine evaluates creatinine through blood tests. High creatinine levels may mean a person is severely dehydrated and also helps indicate if a person is experiencing kidney failure.

One of the more interesting uses of synthesized creatine is when top athletes use it. It is not a banned substance and many athletes claim they use it because it enhances performance naturally. Though tests have not shown creatine to be unsafe, there have not been enough tests to indicate that long-term use is safe.

Tests evaluating ingested creatine have been minimal and suggest that creatine may have a slight benefit in increasing muscle mass and enhancing athletic performance. The benefits are very slight, but many athletes contend it is often the little things that make a difference between winning or losing a race, for example. This is true especially when many ranking in races often come down to a few hundredths of a second. However, creatine does not show improvement in tests on aerobic performance.

Because creatine may be indicated in building muscle mass, body builders may also use it. It can be taken in powder form or in pill form. One side effect noted by many who take creatine is mild to severe muscle cramping. This is often significant enough to cease taking it.

Some medical researchers have studied creatine for its possible benefits in muscle-wasting diseases like multiple sclerosis, and amyotrophic lateral sclerosis. In mice studies, there is the suggestion that increased supplies of creatine may prolong life and help stop apoptosis or cell death of muscle cells. Medical researchers are also examining the virtues of creatine supplementation in those with arthritis and heart failure. As yet, these studies have not shown proven results or benefits to humans.