Does Creatine Damage Your Kidneys? What the Human Evidence Shows
If you've been told to stay away from creatine because it will wreck your kidneys, you've heard one of the most repeated warnings in sports nutrition. Coaches say it, some doctors still say it, and lab reports seem to back it up when a creatine user's kidney numbers come back high. It usually comes paired with a second idea: creatine is a bodybuilder's supplement, so anyone who isn't chasing size has no reason to take it. For healthy adults at normal doses, the human research doesn't support either claim. Real exceptions exist, and we cover them below.
Verdict (2 of 5): Not supported. In healthy adults taking normal doses, controlled trials and meta-analyses find no evidence that creatine damages the kidneys, and its benefits have been studied in older adults, women, and athletes well outside bodybuilding.
Evidence grade: Moderate. Several randomized trials, two meta-analyses, and two expert reviews point the same way. The trials are mostly small, many run for weeks rather than years, and young men are overrepresented. There is very little trial data in people who already have kidney disease.
This article is informational only and is not medical advice.
What claim is being tested
This post looks at two claims that usually travel together:
Creatine damages the kidneys in healthy people who take it at typical doses.
Creatine is only useful for bodybuilders.
By creatine, we mean creatine monohydrate, the form used in nearly all research. A typical dose is 3 to 5 grams a day, sometimes after a short loading phase of about 20 grams a day for five to seven days. Other forms, and doses far above that range, are not what most of the studies tested.
By kidney damage we mean an actual drop in how well the kidneys filter blood, or signs of injury such as protein leaking into the urine. That distinction turns out to be most of the story.
Why creatine got a reputation for hurting kidneys
Two things built this reputation. The first is a lab effect that is easy to misread. Creatine and creatinine are different molecules. Your muscles store creatine and slowly break it down into creatinine, which the kidneys clear from the blood. Doctors estimate kidney function from the amount of creatinine in a blood sample. Take creatine, store more of it, and you make more creatinine. The lab number goes up, and the estimated filtration rate (eGFR) goes down, even when your kidneys are filtering just as well as before.
The second is a 1998 case report in The Lancet. It described a 25-year-old man whose kidney function got worse while he was taking creatine during soccer training. He already had a kidney disease (focal segmental glomerulosclerosis with relapsing nephrotic syndrome) before he started. The report got wide press coverage, and a small number of similar case reports followed over the next two decades.
Case reports deserve attention because they flag possible problems early. What they can't do is show that creatine caused the injury, and several of the later cases involved people who were also using other supplements or anabolic steroids. Answering the question takes controlled trials.
What human studies show
The most useful studies compare creatine with a placebo and measure kidney function directly, instead of relying only on blood creatinine.
A 2013 trial from the University of São Paulo tested the scenario people worry about most. The participants were men who lifted regularly and ate a high-protein diet, at least 1.2 grams of protein per kilogram of body weight per day. Half took creatine (20 grams a day for five days, then 5 grams a day) and half took a placebo for 12 weeks, and neither the participants nor the researchers knew who got which. Kidney filtration was measured with 51Cr-EDTA clearance, a direct method that extra creatine can't distort. The two groups ended up the same. Creatinine clearance, urea, electrolytes, and urinary protein and albumin barely changed.
Pooled analyses reach the same place. A 2019 systematic review in the Journal of Renal Nutrition, the National Kidney Foundation's journal, examined 15 studies with supplementation periods from five days to about two years and concluded that creatine did not cause kidney damage at the doses and durations tested. A 2025 meta-analysis in BMC Nephrology pooled 12 trials. It found a small rise in blood creatinine, mostly in studies of a week or less, and no significant change in filtration rate. The authors put the creatinine bump down to normal turnover rather than kidney injury.
The International Society of Sports Nutrition reviewed the wider literature in 2017. Its position statement found no compelling evidence that creatine harms kidney function in healthy or clinical populations, including studies using up to 30 grams a day for as long as five years. One caveat: the Council for Responsible Nutrition, a supplement industry trade group, commissioned that paper and gave the lead author a grant. Its conclusions match the independent meta-analyses above, but you should know who paid for it.
That leaves the case reports. They are real and rare, and most involve existing kidney problems, high doses, or several products taken at once. Set against controlled trials that keep finding no harm in healthy people, they don't change the verdict. That's why we rate this claim 2 rather than 1, and why the exceptions further down matter.
Is creatine only for bodybuilders?
No. Creatine helps most with short, repeated bursts of hard effort. That covers sprinting, intervals, and team sports, along with the strength work that keeps older adults steady on their feet.
Older adults. A 2017 meta-analysis pooled 22 randomized trials with 721 men and women whose average ages ranged from 57 to 70. Adding creatine to resistance training increased lean mass by about 1.4 kilograms more than training alone, with larger gains in chest press and leg press strength. For anyone trying to hold on to muscle with age, that's a useful result.
Women. A 2021 review in Nutrients reports that women carry 70 to 80 percent less stored creatine than men, and that creatine improves strength and exercise performance in premenopausal women. The same review found fears of weight gain and other side effects in women largely unfounded.
Brain and memory. A 2024 meta-analysis of 16 randomized trials with 492 adults found a small improvement in memory. Certainty was rated moderate for memory and low for attention, processing speed, and overall cognition, so this one is promising rather than settled.
People who eat little or no meat. Vegetarians tend to have lower muscle creatine stores to begin with and may see a bigger increase from supplementing, according to the ISSN position stand.
Who this verdict does not apply to
The verdict fits healthy adults taking 3 to 5 grams a day of creatine monohydrate. It is less certain, or doesn't apply, in the situations below.
People with kidney disease or reduced kidney function
This includes chronic kidney disease, a single kidney, a past kidney injury, and diabetes or high blood pressure that has affected the kidneys. Trial data in these groups is thin. Talk with your doctor or nephrologist before starting creatine.
Anyone getting kidney blood work
Tell whoever orders the test that you take creatine. Expect blood creatinine to read somewhat higher and eGFR somewhat lower than it would otherwise. Researchers have pointed out that this can make kidney function look worse than it is, so ask whether a test that doesn't depend on creatinine, such as cystatin C, makes sense for you.
Teenagers
The ISSN considers creatine acceptable for adolescent athletes who follow recommended doses with proper supervision. Research in teens is more limited than in adults, so a parent and a doctor should be part of the decision.
Pregnancy and breastfeeding
Creatine in pregnancy is an active area of research, but human trial data is still limited. Don't start it without your obstetrician's input.
High doses, supplement stacks, and certain medications
Most research used creatine monohydrate alone at standard doses. Several of the kidney case reports involved people combining it with other supplements, anabolic steroids, or very high protein intakes. If you take medications that can strain the kidneys, such as regular high-dose ibuprofen or other NSAIDs, check with your doctor first.
Key sources
Source | What it found |
12 weeks of creatine in lifters eating a high-protein diet did not change directly measured kidney filtration (51Cr-EDTA clearance), urea, electrolytes, or urine protein compared with placebo. | |
Across 15 studies lasting 5 days to about 2 years, creatine did not cause kidney damage at the doses and durations studied. | |
Creatine caused a small, mostly short-term rise in blood creatinine but no significant change in filtration rate, consistent with normal turnover rather than injury. | |
No compelling evidence of harm to kidney function in healthy or clinical populations; doses up to 30 g/day for 5 years were well tolerated. Commissioned with industry funding. | |
Reviews 12 common creatine misconceptions, including kidney damage and use outside resistance training, and explains the effect of blood creatinine. | |
The report that started the concern: worsening kidney function in a young man who already had kidney disease before taking creatine. | |
In 22 trials of adults averaging 57 to 70, creatine plus resistance training added about 1.4 kg of lean mass and more strength than training alone. | |
Women have 70 to 80 percent lower creatine stores than men; creatine improves strength and performance in premenopausal women, and fears about side effects are largely unfounded. | |
In 16 randomized trials (492 adults), creatine modestly improved memory (moderate certainty); evidence for other cognitive measures was low certainty. |
Last reviewed and evidence accountability
Last reviewed: November 5, 2026
Reviewed by: Know Bull Wellness
Review scope: Human randomized controlled trials, systematic reviews and meta-analyses, expert position statements, and published case reports on creatine monohydrate and kidney function, plus meta-analyses and reviews of creatine in older adults, women, and cognition.
Verdict scale used: 5 Supported, 4 Mostly supported, 3 Mixed, 2 Not supported, 1 Harmful or false.
Claim reviewed: Creatine damages your kidneys and is only for bodybuilders.
Current verdict: Not supported (2 of 5).
Future updates should give the most weight to:
Randomized trials lasting a year or longer that measure kidney function directly
Trials in people with mild or moderate chronic kidney disease
Studies in women, older adults, and teenagers that report kidney outcomes
Well-documented new case reports of kidney injury with creatine taken alone
Bottom line
If your kidneys are healthy, creatine monohydrate at 3 to 5 grams a day hasn't been shown to hurt them. It also isn't just for people chasing size. It is one of the few supplements with consistent evidence for strength and repeated hard efforts, and there is good evidence that it helps older adults build and keep muscle when paired with lifting.
If you have kidney disease or take medications that affect your kidneys, talk with your doctor before you start. And if you get blood work, mention that you take creatine so a high creatinine number is read in context.
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