Small Supplement-Led Rise In Creatine Is No Worry, Say Experts

HYDERABAD: A gym-goer who takes creatine can receive a blood report that lists raised creatinine and a lower estimate of kidney filtration, even though the kidneys still work normally. Has the supplement injured the kidneys, or has the test counted creatine’s breakdown product?

Hyderabad nephrologists say the second explanation can fit a healthy user, and a 2025 systematic review found a small creatinine rise without a fall in actual filtration.

“The body converts creatine supplements taken to build muscle into creatinine. This can cause a transient rise in creatinine. Even if it is slightly raised, there may be nothing to worry about. It does not necessarily translate into pathology,” said Dr G. Murali Mohan Reddy, a nephrologist in Hyderabad.

Creatine is a compound that the body makes from amino acids and also obtains from meat and fish. Skeletal muscle stores about 95 per cent of it. A part of that store exists as phosphocreatine, which helps cells rapidly restore adenosine triphosphate, or ATP, during brief, intense effort. ATP supplies immediate energy to muscles. Supplementation can raise muscle creatine stores by 20 to 35 per cent and the body converts part of the larger pool into creatinine, a waste product measured in blood.

Laboratories call that blood value serum creatinine. Doctors often use it to calculate estimated glomerular filtration rate, or eGFR, which estimates how much blood the kidneys filter. The calculation treats a higher creatinine value as a possible sign of poorer filtration. A supplement-related rise can therefore push the printed eGFR down even when filtration has not fallen.

Dr Reddy said laboratories estimate eGFR from creatinine rather than measure it directly. “If there is doubt about whether creatine supplementation has altered the estimate, the person can undergo a measured GFR test. It is a cumbersome test, but it can settle the uncertainty,” he said.

However, how can a doctor tell whether the number comes from supplementation or disease? The doctor must read it beside the patient’s baseline result, medical history and other kidney tests.

“Before taking creatine supplements, it is better to undergo a creatinine test so that the person has a baseline value,” Dr Reddy said. He advised against unsupervised use when a person already has kidney disease. “If baseline kidney function is normal and there are no risk factors such as diabetes, hypertension or a family history of chronic kidney disease, there is nothing wrong with taking creatine supplements.”

Dr Reddy said he sees patients who become worried after a report lists high creatinine or low eGFR. “We ask them to stop creatine supplements for one week and repeat the creatinine test. If the level returns to normal, the elevation was due to the creatine supplement, and there is nothing to worry about,” he said.

Many people reported panicking after seeing their report, but tests returned to normal after stopping the usage. “My parents freaked out a lot and consequently so did I, but the doctor said it is a transient issue and a retest with a creatine pause will give normal results,” said Abhinav K, adding, “A test within a week showed normal levels.”

However, Dr Murali says hydration is essential while taking creatine. “Creatine pulls water into the muscles, so users need to maintain good hydration,” he said. He recommended an additional one to 1.5 litres of water a day for users and said dehydration could raise creatinine further.

“People who are new to health usually get afraid of consuming dietary supplements like protein and creatine, but 3 to 5 grams of creatine is safe,” said Arpan Kushwaha, Hyderabad based Yoga and gym instructor. He described a supplement as something that fills a dietary gap rather than replaces food, and also helps with brain and cognitive function.

Creatine research has indeed shown effects of supplementation on memory in healthy individuals. Further, a small 2025 University of Kansas pilot led by Matthew Taylor gave people who had Alzheimer’s disease 20 grams a day for eight weeks and reported higher brain creatine and changes on cognitive tests.

So, a healthy adult who plans to take creatine should obtain a baseline creatinine result, choose a standard creatine monohydrate product and disclose the dose and duration to the doctor before a kidney test. A raised result still deserves attention. The doctor may order cystatin C, measured GFR or a repeat test after a pause instead of diagnosing kidney failure from one estimate.