Benefits & Misconceptions of Creatine Supplementation
- Andrew Kowalski
- 14 hours ago
- 9 min read
Andrew Kowalski, MD FASN
Introduction
Creatine monohydrate (commonly referred to simply as “creatine”) is one of the most-studied dietary supplements. It is naturally synthesized in the human body (mainly in the liver and kidneys) and also obtained via intake of protein-rich foods (especially red meat and fish). While it is widely used by athletes for muscle performance enhancement, its benefits extend beyond muscle strength into cognitive function (brain) and, more unexpectedly, may offer protective effects for kidney (renal) health. That said, a number of misconceptions persist, particularly regarding renal damage. This section unpacks the real benefits, the misunderstandings, and the latest evidence.
The Benefits
1. Muscle Performance & Strength
One of the best-established roles of creatine is in enhancing muscle strength, power and lean mass (especially when combined with resistance training). For example:
A 2024 meta-analysis found that in adults < 50 years of age who undertook resistance training, creatine supplementation produced +4.43 kg (upper-body) and +11.35 kg (lower-body) mean strength gains compared to placebo.
More broadly, the position review by the International Society of Sports Nutrition (ISSN) concluded that after loading, high-intensity/repetitive exercise performance is generally increased by ~10-20% with creatine supplementation.
Mechanistically, creatine helps muscles by increasing intramuscular stores of phosphocreatine (PCr) and free creatine, which facilitates faster repair of adenosine-triphosphate (ATP) during high-intensity effort.
Takeaway for muscles: When you combine resistance training + appropriate creatine use, you’re likely to see better strength and muscle adaptations than training alone.
2. Brain / Cognitive Function
Although less obvious than muscle effects, creatine is showing promising data in brain health and cognition.
A 2024 review found that creatine monohydrate supplementation “may confer beneficial effects on cognitive function in adults, particularly in the domains of memory, attention time, and information‐processing speed.”
A meta-analysis of 10 randomized control trials found that in healthy individuals, creatine supplementation improved memory performance (standard mean difference 0.29; 95% CI 0.04–0.53) and this effect was more robust in older adults (66-76 yrs; SMD = 0.88; 95% CI 0.22–1.55).
Creatine has been studied under conditions of brain energy stress (e.g., sleep deprivation) and showed beneficial changes in cerebral high-energy phosphate metabolism and cognitive performance.
Interpretation: Creatine can support brain energy metabolism (analogous to how it supports muscle energy), especially when the brain is under greater demand (aging, stress, injury). It is not a “magic nootropic” for everyone, but the evidence especially in older or stressed populations is encouraging.
3. Renal (Kidney) Function and Protection
Here, the data is especially interesting because it counters a major misconception (which we’ll address below).
A systematic review & meta-analysis (2019) found that creatine supplementation did not significantly alter serum creatinine or plasma urea in healthy individuals (i.e., no evidence of renal damage.)
A 2013 controlled study in resistance trained individuals on a high protein diet (≥1.2 g/kg/day), using gold-standard measured glomerular filtration rate (GFR by ^51Cr-EDTA clearance), found no change in kidney filtration over 12 weeks of creatine (loading + maintenance).
Reviews emphasize that while supplementing can raise serum creatinine (because creatine spontaneously converts to creatinine), this elevation does not imply kidney dysfunction.
How creatine might help kidneys:
By supporting cellular energy metabolism (especially in organs that rely on energy such as muscle, brain, and kidney), creatine could help tissues cope with stress or injury.
Some researchers suggest that the osmolyte and cell-hydration effects of creatine may help protect renal tubular cells from damage under certain conditions , though direct clinical renal-protection trials are still limited.
Because creatine supplementation is safe for kidneys in healthy individuals, it opens up the idea that maintaining optimal creatine stores could help the kidneys be more resilient, though this is still an emerging hypothesis rather than established fact.
Common Misconceptions (and the Reality)
Misconception | Reality / Evidence |
“Creatine damages kidneys” | In healthy individuals at standard doses (3–5 g/day maintenance; or loading then maintenance), multiple meta-analyses and long-term studies do not show impaired kidney function (e.g., no change in filtration rate). |
“Creatine causes harmful rise in creatinine meaning kidney failure” | Creatinine is a breakdown product of creatine, so when you supplement creatine, serum creatinine may rise — but this is a metabolic effect, not evidence of damage. It can falsely lower eGFR by standard formulae. |
“High-protein diet + creatine overloads kidneys” | The 2013 study in high-protein diet individuals found no adverse renal effect of creatine. |
“Creatine causes kidney stones / dehydration / kidney stress” | Systematic reviews have found no convincing evidence that creatine causes kidney stones or dehydration in healthy users when properly hydrated. |
“Creatine only works for young athletes” | While most data come from athletes, increasing data in older adults suggest benefits for strength and cognition in aging. |
Important caveats:
The “safe kidney function” conclusion is for healthy individuals without existing renal disease. Many sources caution that people with pre-existing kidney disease should consult a healthcare provider before supplementing.
Quality of supplement matters, as with all dietary supplements, manufacturing regulation is less strict than drugs (so third-party testing is advised).
How to Interpret the Evidence – What You Should Know
Dosage matters — Typical maintenance dose is ~3–5 g/day of creatine monohydrate in adults, though “loading” protocols (e.g., ~0.3 g/kg/day for 5–7 days) exist.
Training matters — The muscle-strength benefits are maximized when creatine is paired with resistance training (rather than supplement alone). Without training stimulus, benefit is smaller.
Baseline matters — Individuals with lower baseline creatine stores (e.g., vegetarians, older adults) may show greater relative benefit for cognition/memory.
Renal monitoring context — Because supplementation may raise serum creatinine (without reflecting damage), clinicians may need to interpret kidney-function tests (e.g., eGFR) with context. Awareness of this is vital to avoid misdiagnosis.
Healthy population vs. disease states — While evidence supports safety in healthy people, the effect in people with existing kidney disease (or other comorbidities) is less clear and requires professional oversight. Mostly because CKD patients are frequently excluded for general studies, unless changes in kidney function is one of the goals of the study. Bottom line is that we don't know the answer; although we can speculate that there shouldn't be a difference and the benefits should be the same, unless more studies are done, all we can do is the typical "shoulder shrug" when answering this question.
Why It’s a “Forgotten” Supplement for Overall Health (especially Kidney Protection)
Many think of creatine only as a “body-builder drug”, but when you view it holistically; muscle + brain + kidneys it has broader “health supplement” potential.
The kidney-safety story is under-recognized: despite years of evidence, the outdated myth of “creatine = kidney damage” persists. Clearing that misconception opens the door to considering it in wider health-contexts.
As we age, we lose muscle mass (sarcopenia), brain-processing speed declines, and kidney-function resilience decreases. Creatine offers a multi-organ adjunct: helps maintain muscle and cognitive reserve, and may bolster kidney energy-metabolism resilience.
Because the kidneys are energy-demanding organs (they filter, reabsorb, secrete continuously), anything that supports cellular energy (like creatine) might help maintain renal resilience under stress. While direct “kidney-protection clinical trials” are limited, the underlying logic plus safety data make this a compelling avenue.
For people with demanding lifestyles (e.g., heavy training, long hours, sleep deprivation, aging, lower dietary meat intake), creatine is under-utilized. The evidence suggests it’s not just for athletes—it could be for “everyday health”.
Key Takeaways
Creatine supplementation (when used at recommended doses in healthy individuals) is safe for kidneys — numerous systematic reviews/meta-analyses show no impairment of renal filtration or damage.
Creatine offers real benefits for muscle strength (especially with resistance training) and potential benefits for cognitive/memory function (particularly in older adults or under brain-stress conditions).
The idea that “creatine damages kidneys” is largely a myth in healthy populations; increases in serum creatinine seen during supplementation reflect creatine metabolism, not kidney injury.
Because creatine supports energy metabolism in muscle, brain and possibly kidneys, it deserves consideration as a multi-organ health supplement, not just a gym-aid.
Especially for aging adults, people with lower dietary intake of creatine (e.g., vegetarians/vegans), or those under cognitive/physical stress – creatine could be a “forgotten” tool to maintain strength, brain sharpness, and possibly kidney resilience.
That said: if you have pre-existing kidney disease (or are on nephrotoxic medications), you should consult a healthcare provider before supplementing, in a proactive effort to avoid serious confusion..
Ensure high-quality supplement sourcing (third-party tested), stay hydrated, and pair supplementation with appropriate training and nutrition for best results.
One Last Time
Seeing a rise in serum creatinine does not always equal kidney injury, and this can be taken even deeper that if there is a change in serum creatinine and that change resoleve with minimal intervention (if any at all) then there truly was never an injury.
When asking my students, residents, or fellows to describe what a "typical definition of a injury would be," they usually say "something that leaves damage to the person that will take time to resolve." This is 100% true and should ALWAYS be asked when addressing any change in creatinine or suspecting kidney injury. One key, and simplified, example is if giving a patient hydration by IV fluids and witnessing the creatinine immediatly improve automatically implies that there was NO INJURY. On the other hand, if giving a patient hydration by IV fluids and the creatinine does not change, then there is a strong possibility that there is some damage that needs to be addressed.
This reflexive attribution to assume that there is injury is partially the fault of the definintion of kidney injury "...Any rise in creatinine by more than 0.3mg/dl in a 48hr period or 1.5x baseline numbers in 7 days..." So the reflex that many providers will have is that as soon as there is any "rise" in creatinine, "injury" is the leading reason, and that is it. Creatinine is not a "marker of injury," it is a marker of how the kidney is filtering. So it is correct to say that a change in creatinine suggest some change in filtration, not damage. Unfortunately, this misconception has rarely been challenged or corrected and has gained so much momentum that it is now repeated without thought.
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Creatine Supplementation: Benefits, Misconceptions, and Renal
Safety (Concise Evidence Report)
Creatine monohydrate is among the most studied dietary supplements. Beyond its well-known effects on muscle performance, evidence now spans cognitive function and—critically—renal safety. This brief compiles key, verifiable findings (with direct links) across three domains: muscle, brain, and kidneys.
1) Muscle Performance & Body Composition
The International Society of Sports Nutrition (ISSN) position stand concludes creatine monohydrate is effective for high intensity exercise, strength/power, and lean mass, with an excellent safety profile.
Mechanism: Creatine increases intramuscular phosphocreatine, enabling faster ATP synthesis during repeated high intensity work.
• ISSN Position Stand (2017, open access): safety & efficacy in exercise, sport, and medicine. DOI: 10.1186/s12970-017-0173-z
2) Brain / Cognitive Function
Growing evidence shows creatine can benefit cognitive domains such as memory, attention time, and information processing speed, especially under energy stress (e.g., aging, sleep loss) or in people with lower baseline creatine stores.
• Meta-analysis & systematic review (Frontiers in Nutrition, 2024): Significant positive impact on memory; overall SMD » 0.31 (95% CI 0.18–0.44).
• Meta-analysis (Nutrition Reviews, 2023): Memory improved in healthy individuals; stronger effects in older adults (66–76 y).
3) Renal Function: Safety and Interpretation
Key point: In healthy individuals using recommended doses, creatine has not been shown to impair renal filtration or cause kidney damage. A frequent confusion arises because serum creatinine—used to estimate kidney function (eGFR) can rise modestly during supplementation due to increased creatine-to-creatinine turnover, without reflecting actual renal injury. Gold standard measurement data: In a randomized, double blind, placebo controlled trial of resistance trained adults on high protein diets, measured GFR via 51Cr EDTA clearance was unchanged after 12 weeks of creatine (loading + maintenance).
• Randomized controlled trial with measured GFR (JISSN, 2013): No change in 51Cr EDTA GFR after 12 weeks despite high protein intake. https://pubmed.ncbi.nlm.nih.gov/23680457/ |
• Systematic review & meta-analysis (2019): No significant changes in serum creatinine or plasma urea in healthy users. https://pubmed.ncbi.nlm.nih.gov/31375416/
• ISSN Q&A; / review of misconceptions (2021): No adverse kidney effects in healthy individuals at recommended doses. https://jissn.biomedcentral.com/articles/10.1186/s12970-021-00412-w
Practical Notes for Clinicians & Readers
• Dosing: Commonly 3–5 g/day maintenance. Optional loading » 0.3 g/kg/day for ~5–7 days, then 3–5 g/day.
• Interpretation of labs: Mild increases in serum creatinine while on creatine can artificially lower eGFR estimates; consider Cystatin C or direct GFR measures if concern persists.
• Population scope: Safety data here pertain to generally healthy individuals. Those with established kidney disease or on nephrotoxic drugs should consult a healthcare professional before use. Selected References
• Kreider RB et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine. J Int Soc Sports Nutr. 2017. https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0173-z
• Lugaresi R et al. Does longnterm creatine supplementation impair kidney function in resistancentrained individuals consuming a highnprotein diet? J Int Soc Sports Nutr. 2013.
• Alexandre de Souza ES et al. Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-analysis. 2019. PubMed: https://pubmed.ncbi.nlm.nih.gov/31375416/
• Antonio J et al. Common questions and misconceptions about creatine supplementation. J Int Soc Sports Nutr. 2021.
• Prokopidis K et al. Effects of creatine supplementation on memory in healthy individuals. Nutrition Reviews. 2023.
• Xu C et al. Creatine supplementation and cognition: metananalysis. Frontiers in Nutrition. 2024.