From the Guidelines
Creatine supplements do not appear to negatively affect kidney function in healthy individuals when taken at recommended doses. For healthy adults, the typical dosing protocol involves a loading phase of 20 grams per day (divided into 4 doses of 5 grams each) for 5-7 days, followed by a maintenance dose of 3-5 grams daily. However, individuals with pre-existing kidney disease or impaired renal function should consult with a healthcare provider before using creatine supplements, as noted in a study on Duchenne muscular dystrophy management 1. It's also important to maintain adequate hydration while taking creatine, as it causes water retention in muscle cells. The safety concern stems from the fact that creatine is metabolized to creatinine, which is a waste product filtered by the kidneys and used as a marker of kidney function. While creatine supplementation can temporarily increase creatinine levels, this elevation reflects increased creatine metabolism rather than kidney damage, as discussed in a review of dietary supplements in living kidney donors 1.
Some key points to consider when taking creatine supplements include:
- Maintaining adequate hydration to prevent dehydration and potential kidney strain
- Monitoring kidney function, especially in individuals with pre-existing kidney disease or impaired renal function
- Being aware of potential interactions with other medications or supplements that may affect kidney function
- Discontinuing use and consulting a healthcare provider if unusual symptoms occur, such as severe muscle cramps, unusual weight gain, or decreased urination. A study published in 2020 1 highlights the importance of careful consideration when using dietary supplements, including creatine, in individuals with a solitary kidney or those who have undergone kidney donation. However, the evidence suggests that creatine supplementation does not alter kidney function in healthy individuals, and any potential risks can be mitigated with proper precautions and monitoring.
From the Research
Effects of Creatine Supplementation on Renal Function
- Creatine supplementation appears to be safe for healthy adults when used at recommended loading and maintenance doses, but may be associated with an increased risk of renal dysfunction in people with a history of renal disease or those taking nephrotoxic medications 2, 3.
- Some studies have reported that creatine supplementation can transiently rise serum creatinine levels, which may mimic a kidney disease or lead to overdiagnosis of chronic renal failure 2, 3.
- However, other studies have found that creatine supplementation does not significantly alter serum creatinine levels or induce renal damage in the studied amounts and durations 4, 5.
- A systematic review and meta-analysis found that creatine supplementation did not significantly alter serum creatinine levels or plasma urea values, suggesting that it does not induce renal damage 5.
- It is recommended that creatine supplements should not be used in people with chronic renal disease or using potentially nephrotoxic medications, and that further studies are needed to evaluate the potential adverse effects of prolonged creatine supplementation 2, 3, 6.
Key Findings
- Creatine supplementation is safe for healthy adults when used at recommended doses 2, 3.
- Creatine supplementation may be associated with an increased risk of renal dysfunction in people with a history of renal disease or those taking nephrotoxic medications 2, 3.
- Creatine supplementation does not significantly alter serum creatinine levels or induce renal damage in the studied amounts and durations 4, 5.
- Further studies are needed to evaluate the potential adverse effects of prolonged creatine supplementation 6.