The Creatine Safety Debate — Myth or Risk?
Creatine is one of the most researched and widely used supplements in the world, especially among athletes and gym-goers aiming to improve strength, performance, and muscle mass. Yet despite its strong scientific backing, one question keeps resurfacing: is creatine dangerous? More specifically, is it harmful to your kidneys?
Let’s break down the evidence, cut through the confusion, and take a closer look at the actual risks, and unexpected benefits, of creatine supplementation.
What Is Creatine, Really?
Creatine is a naturally occurring compound made by the body and found in foods like red meat and fish. Around 95% of it is stored in skeletal muscle, where it plays a central role in short-duration, high-intensity energy production. It helps regenerate ATP, the body’s primary energy currency, allowing for repeated bouts of performance – whether that’s sprinting, lifting, or even climbing stairs.
While your body makes creatine on its own, supplementing can increase muscle creatine stores by 20–40%, which is why it’s so effective for performance. But increasing creatine intake also increases creatinine, and this is where the kidney confusion begins.
Creatine and Kidney Function: The Misinformation Problem
Creatinine is a byproduct of creatine metabolism. It’s excreted in the urine and routinely used as a marker of kidney function. High creatinine levels on a blood test can signal impaired kidney clearance. But here’s the key point: elevated creatinine doesn’t automatically mean kidney damage – especially in healthy, active individuals supplementing with creatine.
People with high muscle mass or high physical activity levels naturally produce more creatinine. Increased protein intake can elevate levels as well. Creatine supplementation adds another layer – it can raise blood creatinine slightly, but not because it’s harming the kidneys. It’s simply producing more of a compound that the body already metabolises and excretes.
In other words, an increase in creatinine doesn’t equal kidney failure. It must be interpreted in context – muscle mass, diet, training load, and hydration all matter. This is why using creatinine levels alone without considering the full picture is misleading.
What the Research Says About Creatine Safety
Numerous studies — including long-term trials — have shown that creatine is safe when taken at recommended doses by healthy individuals. In fact, the American College of Sports Medicine, International Society of Sports Nutrition, and multiple clinical reviews have concluded that creatine does not impair kidney function in people without pre-existing renal conditions.
So where did the myth come from? Mostly from misunderstanding creatinine levels and anecdotal reports. But scientific evidence repeatedly shows no negative effect on glomerular filtration rate (GFR), no abnormal changes in blood urea nitrogen (BUN), and no structural kidney damage in healthy users.
That said, if someone has existing kidney disease or a known impairment, creatine may not be advisable. In these cases, supplementation should only occur under medical supervision.
Are There Any Side Effects?
Creatine is generally well tolerated, but like any supplement, it’s not completely side-effect free. The most common issues include:
Gastrointestinal discomfort (especially if taken in large doses without water)
Temporary weight gain from increased water retention in muscle cells
Mild cramping or bloating in some individuals
These are dose-related and typically resolved by splitting the daily dose, increasing fluid intake, and avoiding unnecessary loading phases. There’s no evidence that long-term use at recommended doses causes harm in healthy individuals.
Creatine’s Role Beyond Sport
Creatine isn’t just for athletes. Emerging research is uncovering benefits that extend into ageing populations and clinical settings. One of the most promising applications is sarcopenia – age-related muscle loss. When paired with resistance training, creatine supplementation can significantly enhance muscle strength, preserve lean mass, and reduce the risk of falls in older adults.
Here’s where things get even more interesting: creatine may also play a protective role in neurological and cardiovascular conditions. Animal models have shown reductions in brain infarct size after ischemic strokes and improved cognitive outcomes following traumatic brain injury. There’s also evidence that creatine supports myocardial energy supply during cardiac ischemia – which is why phosphocreatine is sometimes used clinically in heart failure cases.
Most of these findings come from rodent models, but the underlying mechanism – improved cellular energy availability – is applicable across tissues. With its strong safety profile, creatine is being studied as a potential adjunct therapy in conditions far removed from sports performance.
Final Verdict — Is Creatine Dangerous?
In healthy individuals, no – creatine is not dangerous. It’s one of the most effective, affordable, and well-researched supplements available today. When taken at recommended dosages, it supports physical performance, enhances recovery, and may even offer protective benefits beyond the gym.
For individuals with existing kidney disease or at risk of renal complications, caution is advised – but that’s true of many supplements and medications. For the average person, the fear around creatine is based more on misinterpretation than on science.
So if you’re wondering whether creatine belongs in your routine: for most people, the answer is yes – and confidently so.
References
- American College of Sports Medicine (ACSM). (2009). Position Stand: The use of creatine in sport. Medicine and Science in Sports and Exercise, 41(7), 1450-1467. doi: 10.1249/MSS.0b013e3181aae7c3
- Poortmans, J.R., & Francaux, M. (1999). Adverse effects of creatine supplementation: fact or fiction? Sports Medicine, 28(2), 65-74. doi: 10.2165/00007256-199928020-00002
- Buford, T.W., Kreider, R.B., Stout, J.R., Greenwood, M., Campbell, B., Spano, M., Ziegenfuss, T., Lopez, H., Landis, J., & Antonio, J. (2007). International Society of Sports Nutrition position stand: creatine supplementation and exercise. Journal of the International Society of Sports Nutrition, 4(6). doi: 10.1186/1550-2783-4-6
- Kreider, R.B., Kalman, D.S., Antonio, J., Ziegenfuss, T.N., Wildman, R., Collins, R., Candow, D.G., Kleiner, S.M., Almada, A.L., & Lopez, H.L. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14(18). doi: 10.1186/s12970-017-0173-z
