Are Creatine Supplements Bad For Your Kidneys? What's Fact vs. Fiction

Creatine supplements are getting a lot of attention these days. Influencers are sharing how these powders helped transform their body composition, recovery, and strength. And new research is being published on the compound's cognitive capabilities (like this recent study showing its energizing effects after sleeping poorly). 

But there's also some information circulating that creatine is bad for kidney health. This noise is so loud that people are hesitant about the supplement's safety profile, which is fair.

You should always confirm the safety and effectiveness of a supplement before giving it a go. 

Decades of research demonstrates that creatine supplements are safe and have minimal side effects1 in healthy individuals. The notion that it could negatively impact kidney health (for people without preexisting kidney problems) is a common misconception. 

How did this misinformation spread? Well, as creatine supplements can help improve physical performance2 (like enhancing muscle mass and strength), people have wrongly perceived this compound to be a steroid—which it is very much not.* 

Anabolic steroids, classified as drugs, are regulated substances and can aggravate the kidneys3. 

Creatine, on the other hand, is a compound that is simply derived from the amino acids glycine, arginine, and methionine. It's a completely different chemical structure and impacts performance in a completely different way (by supporting the body's ATP energy production4).*

However, one case report5 published in 1998 severely tarnished the compound's reputation and continues to be a source of misinformation to this day. 

In this report, authors cited creatine supplements as a contributing factor to a young man's renal dysfunction.

While this paper was published in a well-respected scientific journal (Lancet), the authors inaccurately represented creatine's role—so much so that two other teams of creatine researchers wrote letters to the editor. However, the information had already circulated, and people had something to reinforce their apprehension. 

Since then, researchers have conducted numerous experimental, controlled research trials to investigate the effects of creatine and kidney health, and the results are consistent.

The sticky relationship between creatine and kidney health has persisted all these years thanks to creatinine4. Clinically high creatinine levels are used as an indicator that something may be off with the kidneys—but it is not a direct measure of kidney function. 

For some people, "Taking a creatine supplement may increase blood levels of creatinine (a waste product from the digestion of protein)," says Michelle Darian, M.S., MPH, R.D.

As creatinine is a waste product of protein digestion and muscle metabolism, creatine supplements as well as high-protein diets7 and high levels of lean body mass8 can all increase creatinine levels, which doesn't reflect poor kidney function. 

Another blood biomarker people think creatine increases—and therefore negatively impacts—is one called creatine kinase9. 

As a dietitian at the personalized health platform InsideTracker (which includes blood testing), Darian gets asked this question all the time by customers. 

"Creatine kinase is a measure of muscle breakdown—with higher levels indicating more muscle breakdown," notes Darian. "People that see a really elevated creatine kinase level often jump to the conclusion that their creatine supplement is the culprit, but that's not the case."

And most research shows taking a modest 5-gram dose (typically just one small scoop of powder) is ideal—in addition to regular exercise, of course. 

Misinformation about creatine and kidney function has been rampant for years. But all the research to date does not show side effects at the recommended doses of creatine supplementation on kidney health for healthy people6.