Creatine and Kidney Function: What You Need to Know

When you take creatine, a naturally occurring compound that helps muscles produce energy during short bursts of activity. It's one of the most studied supplements in the world, used by athletes, older adults, and even people recovering from injury. But a lot of people worry: does creatine hurt your kidneys? The short answer? For healthy people, no—but here’s what you really need to know.

Kidney function, how well your kidneys filter waste and balance fluids in your body is often checked through blood tests like creatinine levels. Since creatine breaks down into creatinine, some assume high creatinine means kidney damage. It doesn’t. That’s just a side effect of the supplement, not a sign of harm. Studies from the Journal of the International Society of Sports Nutrition and others have followed people taking up to 30 grams of creatine daily for years—and found no negative impact on kidney health in those with normal kidney function.

But here’s the catch: if you already have kidney disease, you should talk to your doctor before starting creatine. Your kidneys might not handle the extra load, even if it’s not proven to cause damage. Also, staying hydrated matters. Creatine pulls water into your muscles, so if you’re not drinking enough, you could feel dehydrated or put extra strain on your system. That’s not a kidney problem caused by creatine—it’s a hydration issue.

Creatine safety, how safe it is to use over time, especially when combined with other supplements or medications is another big question. People stack creatine with protein, pre-workouts, or even NSAIDs like ibuprofen. While creatine itself doesn’t interact badly with most meds, combining it with kidney-stressing drugs—like some antibiotics or painkillers—could raise risks. Always check with your pharmacist if you’re on multiple meds.

And what about long-term use? A 2020 review of 27 clinical trials found no signs of kidney damage in healthy adults using creatine for up to five years. That’s longer than most people take it. The real danger? Not taking it when you could benefit—especially if you’re over 50 and losing muscle mass, or recovering from surgery. Creatine helps you rebuild strength faster, which actually reduces stress on your body overall.

So if you’re healthy, drinking water, and not on kidney-toxic drugs, creatine is likely safe. But if you’ve ever had kidney stones, high blood pressure, or been told your kidneys are "a little off," get tested first. Don’t guess. A simple blood test can tell you if your kidneys are handling things fine.

Below, you’ll find real-world guides on how creatine fits into your health routine—when it helps, when it doesn’t, and how to avoid the common mistakes people make. You’ll see how it compares to other supplements, what to watch for, and how to use it smartly without risking your health.