 The Society for Sarcopenia Cachexium Wasting Disease convened an expert panel that, despite the lack of long-term trials, suggested creatine be used for the management of age-related muscle loss, also known as sarcopenia. Are there any creatine side effects? Well, if one can extrapolate from mice, one side effect may be longevity. The average healthy lifespan of creatine-fed mice was found to be 9% more than control mice, and they performed better on neurobehavioral tests, especially improved memory skills, but is taking creatine safe. One can take a bit of comfort in the fact that it's one of the world's best-selling dietary supplements with literally billions of servings taken, and the only consistently reported side effect has been weight gain, presumed to be from water retention. The only serious side effects appear to be among those with pre-existing kidney diseases taking whopping doses of like 20 grams a day for weeks. The bottom line, according to the European Food Safety Authority, is that doses of up to 3 grams a day are unlikely to pose any risk, provided high-purity creatine is used. Dietary supplements are not regulated by the FDA and may not actually contain what's on the label, or in the case of creatine be tainted with contaminants generated during the industrial production process. When researchers looked at 33 samples of creatine supplements made in the US and Europe, they all did actually contain creatine, that's good. But half exceeded the maximum level recommended by Food Safety Authorities for at least one contaminant. The researchers recommend that consumers choose products from producers that ensure the highest quality control, but that's easier said than done. One third-party supplement testing outfit that tested for purities chose bulk supplements brand, as their top pick, which also happened to be the cheapest at about $0.10 per daily 5-gram serving, which is a level teaspoon. What about just getting it from meat? You could get that 3 grams of creatine, eating about 5 steaks a day, since cooking destroys about 20%, but the heat reacts with the creatine and amino acids in meat to create carcinogenic heterocyclic amines, and one of the reasons meat is considered to be cancer-causing. A separate safety concern was raised that creatine in supplement form could potentially form a different carcinogen known as N-nitrososarcazine when it hit the acid bath of the stomach, but when actually put to the test, this does not appear to be a problem. Some have argued caution for creating use among those with kidney issues. This concern appears to derive in part from a misinterpretation of laboratory data. The blood levels of a different compound called creatinine is used as a marker of kidney function. It's a muscle metabolism waste product that is regularly cleared out by well-functioning kidneys. So if your levels rise, maybe your kidneys aren't doing so good. But where does creatinine come from? The breakdown of creatine. So if you take extra creatine, your creatinine levels in your blood could rise, giving the false impression that your kidneys are malfunctioning, but instead you're just making more, rather than clearing less. For patients who take creatine, doctors can consider other kidney function tests, such as blood levels of C-statin C levels, a waste product that's more independent of dietary intervention. So tell your health care professional if you start creatine. Overall, creatine supplementation appears to be safe for the kidneys, but the longest study to date is less than three years, so true long-term studies are lacking.