Short answer: For most healthy adults, yes. At the usual 3 to 5 g a day, creatine has not harmed kidney function in controlled trials, and people have been studied taking it for up to 5 years (3, 1). It can nudge up creatinine, a common kidney blood test, without real damage. If you have kidney disease, ask your doctor first.

What to know about creatine and your kidneys

Creatine is one of the most researched supplements in sports nutrition and clinical science. Despite decades of data supporting its safety in healthy people, the worry about kidney damage hangs on. Most of that fear comes from confusion around one lab marker: serum creatinine.

Your body breaks creatine down into creatinine, so taking creatine can raise your measured creatinine a little. A higher number does not automatically mean kidney injury. The real question is whether creatine harms how well your kidneys work, measured by glomerular filtration rate (GFR), creatinine clearance, cystatin C, protein in the urine, or kidney structure.

When studies look at those measures, they keep finding the same thing: creatine does not impair kidney function in healthy people at recommended doses (5, 16).

Does creatine raise creatinine? The lab test confusion

Serum creatinine is the usual way to estimate kidney function, but it is an indirect marker. Muscle mass, how much cooked meat you eat, how well hydrated you are and creatine supplements can all move it. The National Kidney Foundation lists creatine supplements among the things that can raise creatinine and make your estimated GFR (eGFR) look lower than it really is (14).

Because eGFR formulas lean on creatinine, the report can suggest your kidneys are slowing down when filtration is actually normal. This is sometimes called a "pseudo-elevation." The National Kidney Foundation notes that an eGFR calculated from both creatinine and cystatin C is more accurate than either one alone (14). Cystatin C is far less affected by muscle and creatine, so it is a useful second check if your number comes back high.

Kidney test Can creatine change the number? What it means for you
Serum creatinine Yes, it can read a little higher (5, 14) Tell whoever orders your labs that you take creatine
eGFR based on creatinine Yes, it can look lower than your true filtration (14) Ask whether a cystatin C based eGFR makes sense
Cystatin C Did not show kidney problems in a 3-month creatine trial (2) A fairer second check when creatinine reads high
Measured clearance (creatinine, urea, albumin) No difference vs non-users after 10 months to 5 years (1) A direct measure of filtration, used in research

Evidence from controlled clinical trials

Several studies have looked straight at kidney function in people taking creatine. One of the earliest compared athletes who had taken creatine for 10 months to 5 years with a control group. Creatinine, urea and albumin clearance were the same in both groups, and filtration was normal (1).

Randomized trials using more specific tests agree. In a double-blind, placebo-controlled trial, young men took about 10 g a day for 3 months, roughly double the usual dose. Their cystatin C, which is much less influenced by muscle or creatine, went down over time rather than up, which points to no kidney dysfunction (2).

These findings matter because they show that even when creatinine edges up, more direct measures of filtration stay steady. That supports the view that the creatinine change is about metabolism, not kidney damage.

What reviews and meta-analyses show

A 2019 systematic review screened 290 studies, included 15 and pooled 6. The authors concluded that creatine "does not induce renal damage in the studied amounts and durations." Look closely at the numbers, though: the pooled data did show higher serum creatinine and urea in creatine users (5). That fits the lab effect described above, and it is exactly why your doctor should know you take creatine.

Position statements from sports nutrition groups echo these findings. The International Society of Sports Nutrition reviewed the safety research and wrote: "These studies show that short and long-term supplementation (up to 30 g/day for 5 years) is safe and well-tolerated in healthy individuals and in a number of patient populations ranging from infants to the elderly. Moreover, significant health benefits may be provided by ensuring habitual low dietary creatine ingestion (e.g., 3 g/day) throughout the lifespan." (3). A 2021 review of common creatine questions lists kidney damage among the most common misconceptions (16). One caution: some authors of these position papers report advisory ties to creatine makers.

Long-term use, older adults and diabetes

A common concern is whether years of creatine could slowly wear the kidneys down. Studies that followed users for months to years have not shown a gradual decline in healthy people (1, 3). Most trials last months, not decades. So the data is reassuring, but it has limits.

Older adults. In a 2-year trial, 200 postmenopausal women took 3 g of creatine or a placebo every day. Creatine did not change the health-related lab tests the researchers tracked (9). Still, kidney function tends to fall with age, and many older adults take several medicines, so a quick check with your doctor is sensible after 60.

Type 2 diabetes. In a 12-week randomized, double-blind trial in people with type 2 diabetes who also exercised, creatine did not change kidney filtration measured with a precise tracer test. Creatinine clearance, urea, electrolytes and protein in the urine were also unchanged (6). Diabetes is still a reason to talk with your doctor first, because diabetes itself can affect the kidneys.

Why the myth persists

Several things keep the worry alive:

  1. Misread lab results: A creatinine rise from normal creatine metabolism can be mistaken for kidney damage.

  2. Case reports: Isolated reports describe kidney problems in people taking creatine. These often involved existing kidney disease, extreme doses, dehydration, other supplements or other medical problems. Case reports cannot prove cause and do not reflect the wider trial data.

  3. Mix-ups with high-protein diets: People who take creatine often eat more protein too. A higher blood urea nitrogen (BUN) from protein can be blamed on creatine.

  4. Workload confused with injury: Healthy kidneys adjust to changes in what they filter. Extra work is not the same as damage.

Who should check with a doctor first?

The evidence supports safety in healthy adults. These groups should talk with a healthcare professional before starting, because creatine has not been studied as well in them:

  • People with diagnosed chronic kidney disease (CKD)
  • Anyone with protein in the urine or abnormal kidney labs
  • People taking medicines that can affect the kidneys
  • Anyone with a history of glomerulonephritis or structural kidney problems
  • People with diabetes, especially if you use insulin
  • Anyone with surgery coming up (see the next section)

Creatine and surgery: pre-op labs and recovery

If you take creatine and have surgery coming up, the main kidney issue is not harm. It is how your pre-op blood work reads. If your labs include creatinine or eGFR, a creatine-related bump could raise questions. Tell your surgical team you take creatine, show them the label, and ask whether to keep taking it up to surgery. Your surgical team's instructions come first.

After surgery, be realistic about what creatine can do. In the one trial around knee replacement, creatine did not improve strength or function in the first month (13). After ACL reconstruction, it added no strength gain in the first 12 weeks of rehab (11). Where it has shown promise is later, once strength work starts: in healthy adults whose leg was in a cast for 2 weeks, creatine plus rehab training supported faster regain of thigh muscle size and power (12). Creatine is not proven in surgical studies, but it can be an adjunct. If you are later in your recovery and struggling to regain strength, it is worth considering. Our guides to supplements after knee replacement surgery and supplements after ACL surgery go deeper on each procedure.

What to expect after you start creatine

This assumes a steady 5 g a day with no loading phase, which is how the Recovery and Strength Mix is designed to be used. Results vary, and none of this is a promise.

When What is happening What to do
Before you start Nothing yet. This is the moment to rule out kidney disease or abnormal labs. If you are in a group listed above, ask your doctor first. If you have recent labs, note your creatinine and eGFR.
Week 1 Muscle creatine starts to rise slowly. Most people notice nothing. Take it at the same time each day and drink fluids as usual.
Weeks 2 to 4 Stores fill. In one study, 3 g a day for 28 days raised muscle creatine by about 20%, the same rise as a 6-day loading phase (7). At 5 g a day you would expect a similar rise over about the same month. Keep training or doing physical therapy. That is where the benefit comes from.
Any blood test from here on Creatinine may read a little higher (5). Tell the person ordering the test. Ask about cystatin C if eGFR looks low (14).
About 3 months, with strength training In 357 older adults training for about 12.6 weeks, creatine plus training improved leg press and chair-stand results more than training alone (8). Lift or do resistance work 2 to 3 days a week. You might notice an extra rep or easier chair rises. Not guaranteed.
Up to a year, with strength training Across 22 trials (721 adults, average age 57 to 70, 7 to 52 weeks), creatine with training added on average 1.37 kg more lean tissue than placebo (4). Keep protein up and keep training. Without training, 3 g a day for 2 years did not add lean mass in older women (9, 10).
If you stop Muscle creatine drifted back to its starting level within about 30 days of stopping in one study (7). No tapering needed. Tell your doctor if you stopped before a blood test.

If you have surgery coming up

When Creatine and kidneys Nutrition routine
Before surgery Tell your team you take creatine, mainly so pre-op creatinine and eGFR are read correctly. Ask whether to keep taking it. Start one OptiFuel packet a day about 1 week before surgery. OptiFuel contains no creatine.
Night before Follow your team's fasting rules for anything by mouth. If your team approves, 2 OptiCharge packets at bedtime, each in 12 to 16 oz of water. In a randomized trial, a carbohydrate drink before surgery left people less hungry and less anxious than fasting (15). If you have diabetes, ask first.
Week 1 after Restart supplements only when your surgical team says you can. Creatine has not shown early benefit after knee replacement (13). Focus on eating and protein. Restart OptiFuel when you are eating again.
Weeks 2 to 6 Physical therapy drives early strength. After ACL surgery, creatine added nothing in the first 12 weeks (11). Daily OptiFuel through recovery. Keep up with PT.
After 6 weeks Once strength work picks up, creatine with training supported faster regain of muscle size and power after a cast (12). If strength is slow to return, creatine is worth considering. Mention it at your next follow-up.

Practical tips for taking creatine safely

For healthy people thinking about creatine:

  • A standard dose of 3 to 5 g of creatine monohydrate a day is well supported by safety data (3, 16). You may also see 0.1 g per kg of body weight: for a 70 kg (154 lb) adult that is 0.1 x 70 = 7 g, a little above the common range.
  • A loading phase is not needed. A steady daily dose reaches similar muscle levels in about a month (7).
  • Count all your sources. If you use more than one product with creatine, add up the grams.
  • If a routine test shows a small creatinine rise after you start, consider repeating it with steady hydration or adding cystatin C before assuming a kidney problem (14).
  • Always tell your healthcare provider about supplements so your lab results are read correctly.

How the Recovery and Strength Mix fits

The Recovery and Strength Mix is the only Thrive product with creatine. Each scoop has 5 g of creatine monohydrate, inside the studied 3 to 5 g range, plus 3 g of leucine, glutamine, 2 g of arginine, isoleucine and valine. It is Informed Sport certified.

Day to day, it looks like this: one scoop in water, once a day. Thrive suggests taking it between lunch and dinner. No loading phase. At $49.99 for 30 servings, that is $49.99 / 30 = about $1.67 a day.

If you have surgery ahead, the Surgical Protocol Kit gives you daily OptiFuel (25 g whey protein with 3 g leucine) plus 2 OptiCharge packets for the night before. If surgery is already behind you, the Recovery Protocol Kit has the same OptiFuel without OptiCharge. Neither kit contains creatine, so Thrive suggests adding the Mix daily, taking OptiFuel between breakfast and lunch and the Mix between lunch and dinner. Thrive Protocol kits are HSA/FSA eligible, so you can use pre-tax health dollars. If you are told to limit protein, for example with advanced kidney disease, check with your doctor before using either kit. For the bigger picture, see our guide to the best supplements for surgery recovery and what to eat after surgery.

Thrive Protocol Recovery and Strength Mix with 5 g creatine monohydrate per scoop

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Bottom line

In healthy people with normal kidney function, creatine at recommended doses does not appear to harm the kidneys. Creatinine may rise a little because of how creatine is broken down, but direct measures of kidney filtration stay stable in controlled trials and reviews.

The idea that creatine damages kidneys is not supported by the weight of the evidence. Context still matters. If you have kidney disease, diabetes or surgery coming up, talk with your doctor or surgical team first. For most healthy adults, creatine monohydrate remains one of the most studied supplements in both sports and clinical research. If muscle and strength after 40 is your main reason for taking it, read how creatine helps with muscle loss after 40.

Frequently asked questions

Does creatine raise creatinine on a blood test?

It can. Your body turns creatine into creatinine, so supplements can push serum creatinine up a little and make a creatinine-based eGFR look lower than your true kidney function (14). A review of kidney studies found this small rise without signs of kidney damage (5).

Should I tell my doctor I take creatine before bloodwork or surgery?

Yes. Tell whoever orders your labs and your surgical team, so a higher creatinine is read in context. Ask whether an eGFR that uses cystatin C makes sense for you. Before surgery, ask your team whether to keep taking creatine, and follow their instructions.

Can you take creatine if you have kidney disease?

Not without your doctor's approval. Most safety studies were done in people with healthy kidneys, so the evidence does not cover chronic kidney disease, protein in the urine or abnormal kidney labs. Your doctor can weigh it against your results and any protein limits you have been given.

Is creatine safe for older adults' kidneys?

The data is reassuring. In a 2-year trial of 3 g a day in 200 postmenopausal women, creatine did not change the health-related lab tests the researchers tracked (9). Kidney function often declines with age and older adults take more medicines, so check with your doctor first.

Is creatine safe if you have type 2 diabetes?

In a 12-week randomized trial in people with type 2 diabetes, creatine did not change kidney filtration, protein in the urine or other kidney markers (6). Diabetes can affect the kidneys on its own, so ask your doctor before starting.

How much creatine per day is safe?

For healthy adults, 3 to 5 g a day of creatine monohydrate is the usual, well-studied dose (3, 16). You do not need a loading phase; a steady daily dose fills muscle stores in about a month (7). One scoop of the Recovery and Strength Mix gives 5 g.

This article is for education and does not replace advice from your doctor or surgical team. Your surgical team's instructions come first.

References

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  11. Tyler TF, et al. The effect of creatine supplementation on strength recovery after anterior cruciate ligament (ACL) reconstruction. Am J Sports Med. 2004;32(2):383-388. PubMed 14977662

  12. Hespel P, et al. Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. J Physiol. 2001;536(Pt 2):625-633. PubMed 11600695

  13. Roy BD, et al. Creatine monohydrate supplementation does not improve functional recovery after total knee arthroplasty. Arch Phys Med Rehabil. 2005;86(7):1293-1298. PubMed 16003653

  14. National Kidney Foundation. Creatinine. kidney.org/kidney-topics/creatinine

  15. Hausel J, et al. A carbohydrate-rich drink reduces preoperative discomfort in elective surgery patients. Anesth Analg. 2001;93(5):1344-1350. PubMed 11682427

  16. Antonio J, et al. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr. 2021;18(1):13. PubMed 33557850