According to Kurtis Frank and Sol Orwell of Bodybuilding.com, creatine supplementation is generally considered to be safe for people who do not suffer from any type of kidney disorder that may cause edema or other related tissue swelling. Conditions such as polycystic kidney disease and focal segmental glomerulosclerosis have been shown to react poorly to creatine supplements. Otherwise, the use of creatine has been scientifically proven to be safe.
Creatine is known to cause a few unwanted side effects in people who use it excessively, such as fluid retention, nausea and diarrhea. None of these conditions are cause for alarm and are easy to regulate by taking smaller doses of creatine or by increasing water intake along with the supplement. Frank and Orwell warn that people who are being treated for hypertension should avoid creatine as complications may occur. Creatine is sometimes associated with heart and liver issues, but scientific research into the effects of the supplement have not proven these concerns to be true. WedMD explains that creatine occurs naturally in the body and can also be found in some food sources. The main goal of people who supplement with the substance is to increase muscle mass and overall athletic performance. Creatine has been shown to aid fitness enthusiasts in working out for longer periods of time before becoming fatigued.