According to WebMD, some benefits of using creatine include improved athletic performance for select groups of people, such as vegetarians; improved academic performance in children suffering from certain creatine deficiency disorders; and slowing down the advancement of Parkinson's disease. Some negative side effects include muscle cramping and stomach pains.
People primarily use creatine to stimulate increased muscle mass and improve performance in exercise and sports, according to WebMD; however, creatine does not work for everyone. According to Brittany Risher of Men's Health, creatine is best suited for activities that require short, sustained bursts of energy, such as baseball and football. Creatine is also used to treat rheumatoid arthritis, depression, congestive heart failure and high levels of cholesterol, notes WebMD. Creatine is used in the treatment of individuals who cannot manufacture creatine naturally, a condition that can cause autism, seizures and psychological retardation. Creatine treats arginine-glycine amidinotrasferase, a creatine deficiency disorder.
The chemical does not improve endurance in sports or other athletic activities, according to Risher. In addition, creatine does not improve the performance of individuals over 60 years old, highly trained athletes and anyone who consumes meat or fish, both good sources of creatine. The chemical can also cause dehydration because it stimulates muscles to draw large quantities of water from the rest of the body. For this reason, WebMD cautions users to avoid exercising in the heat and to drink a lot of water. Pregnant and lactating mothers and those with kidney problems should avoid using creatine.
Creatine should not be used outside of physical activity, or it can cause unwanted weight gain, says Risher. There is anecdotal evidence suggesting that creatine may cause kidney damage, heart problems, muscle cramps, dehydration and diarrhea, but these claims have not been proven in focused studies. Children under 18 should avoid taking creatine until more research has been conducted to test the effects of the supplement on that age group.