Medically Reviewed by Christine Mikstas, RD, LD on June 05, 2023
2 min read

Creatine is formed from amino acids and plays a role in converting food into energy. We get some creatine from our diets, mostly from meat and fish, and our bodies make the rest naturally. Creatine is also a popular and somewhat controversial supplement used by some athletes in the belief that it enhances performance.

Despite creatine’s wide use, the evidence that creatine supplements improve athletic performance is inconclusive. The potential benefits of creatine may depend on many factors, including age, fitness level, diet, and athletic activity. There is some good evidence that creatine might help modestly with sports that require sudden bursts of activity. Examples are sprinting or weightlifting. It may also increase muscle mass in some people.

However, the evidence that creatine boosts stamina or performance in aerobic activity is mixed. It may not have the same benefits in older people. Since it causes water retention, creatine could slow down some athletes.

Researchers have also studied creatine as a treatment for many health conditions. There is ongoing research to see if it  might help with congestive heart failure, Parkinson’s disease, and muscular dystrophy, but more research is needed. Creatine has also been studied for conditions such as Huntington’s disease and Lou Gehrig’s disease, and to help with bone health. But the results have been conflicting or inconclusive.

Creatine is an unproven treatment. There is no established dose. Many different dosages of creatine supplements have been used in studies. For athletic performance, some people start with 10 grams to 20 grams of creatine a day. This is typically followed by a maintenance dose of 2 grams to 5 grams of creatine a day.

Natural food sources of creatine include meat, poultry, and fish.

  • Side effects of creatine may include kidney disease and kidney failure, water retention, nausea, diarrhea, cramping, muscle pain, and high blood pressure. To prevent dehydration, experts often suggest drinking plenty of water when using creatine.
  • Interactions. Large amounts of carbohydrates may increase the effects of creatine. Caffeine may decrease the muscle effects. Using creatine along with stimulants such as caffeine, guarana, and others could potentially cause dangerous cardiovascular side effects.
  • Risks. The long-term risks of creatine are unknown. People with kidney or liver disease should not take creatine. Creatine may affect blood sugar levels, so the supplement may not be safe for people with diabetes.

Given the lack of evidence about its safety, creatine is not recommended for children or for women who are pregnant or breastfeeding. Consult your doctor before taking creatine supplements.