Does Creatine Damage Your Kidneys? A Simple, Honest Answer

For healthy people taking normal amounts, no — creatine does not appear to damage your kidneys. It can make one number on your blood test look higher, which scares a lot of people. But that higher number is normal and expected, and it doesn't mean your kidneys are in trouble. Here's why, in plain English.

Why your blood test suddenly looks scary

You start taking creatine to help with your training. A few weeks later you get a blood test, and one result is flagged as HIGH: something called creatinine.

Right away it feels alarming, because creatinine is the number doctors often use to check the kidneys. So it's easy to think, "Did I just hurt my kidneys?"

The good news: there's a simple explanation.

Creatine turns into creatinine — that's the whole trick

Here's the part almost nobody explains:

• Creatine is the supplement you take.
• Creatinine is what your body naturally makes from it.

They sound almost the same, and that's the point — one becomes the other. Your body turns creatine into creatinine every single day.

So if you put more creatine in, you'll naturally have a little more creatinine showing up in your blood. The test going up is exactly what you'd expect. It's not a sign of damage.

Picture a bathroom scale

Imagine you drink a big glass of water and then step on the scale. The number goes up. Did you suddenly gain fat? Of course not. You just added water, and the scale is doing its job.

Creatine works the same way. The number on your blood test goes up, but nothing about your actual kidneys has changed.

Download the full briefing Creatine & Your Kidneys — The Evidence in Full PDF · the complete, referenced version to read or print

What the research actually shows

To check this properly, researchers in 2026 combined 20 studies and looked not just at creatinine, but at the tests that show how well the kidneys are truly filtering blood.

Here's what they found:

• Creatinine went up a tiny bit — just as expected.
• The real "filtering" tests showed no meaningful change.
• It didn't matter whether people took creatine for a few weeks or much longer — the result was the same.

In other words: the number on the test moved, but how well the kidneys worked did not. (Researchers do say they'd like even longer studies, lasting more than a year, to be completely sure over the long term — which is a fair and normal thing for scientists to want.)

So should you stop taking creatine?

Not because of that one flagged number alone.

A "high" creatinine in someone taking creatine is usually just the supplement showing up — not a kidney problem. The smarter move is:

• Don't panic over a single result.
• Tell your doctor you take creatine so they can read the test correctly.
• If you want extra reassurance, your doctor can run a different blood test (one called cystatin C) that isn't affected by creatine, giving a cleaner picture.

When a high creatinine is worth checking

To be fair and safe, a high creatinine should always be looked at properly by a doctor if you also have:

• An existing kidney problem
• Diabetes, high blood pressure, or heart disease
• New symptoms like swelling, tiredness, or peeing much less than usual
• A number that keeps climbing on repeat tests, instead of a one-off

If any of those apply to you, talk to a doctor before drawing conclusions.