Creatine is the top sports performance supplement available. Yet despite its research-backed benefits, some people avoid creatine because they worry it’s bad for their health.
Some claim it causes weight gain, cramping, and issues with digestion, the liver, or the kidneys. But hundreds of studies support its safety and effectiveness.
This article provides an evidence-based review of creatine’s safety and side effects.
Depending on who you ask, the suggested side effects of creatine may include:
- kidney damage
- liver damage
- kidney stones
- weight gain
- muscle cramps
- digestive concerns
- compartment syndrome
Is creatine a steroid?
One study examined 69 health markers after participants took creatine supplements for 21 months. It found no adverse effects (
Is creatine safe to take every day?
Research has shown that it is safe to consume creatine supplements daily, even over several years.
There is no evidence to support any significantly detrimental side effects in people who consume high doses of creatine (30 grams/day) for up to 5 years (
In fact, research has shown positive health benefits in athletes who took daily supplements of creatine for long periods of time (
Although some people make false claims about creatine’s side effects and safety issues, none of them are supported by research.
Creatine is found throughout your body, with 95% of it stored in your muscles (
Your diet and natural creatine levels do not typically maximize muscle stores of this compound.
The average stores are about 120 mmol/kg in someone who weighs 154 pounds (70 kg), but creatine supplements can elevate these stores to around 160 mmol/kg (
Once you fill your muscle’s creatine stores, any extra is broken down into creatinine, which is metabolized by your liver and released in your urine (
Around 95% of the creatine in your body is stored in your muscles. There, it provides increased energy for high intensity exercise.
This fact may be behind the theory that creatine causes dehydration. However, this shift in cellular water content is minor, and no research supports the claims about dehydration.
A 3-year study of college athletes found that those taking creatine had fewer cases of dehydration, muscle cramps, or muscle injuries than those not taking it. They also missed fewer sessions due to illness or injury (
One study examined creatine use during exercise in hot weather, which can accelerate cramping and dehydration. During a 35-minute cycling session at 99°F (37°C), creatine had no adverse effects on cyclists, compared with o a placebo (
Further examination via blood tests also confirmed no difference in hydration or electrolyte levels, which play a key role in muscle cramps (
The most conclusive research has been conducted in individuals undergoing hemodialysis, a medical treatment that may cause muscle cramps. Researchers noted that the group taking creatine experienced a 60% reduction in cramping (
Based on the current evidence, creatine does not cause dehydration or cramping. If anything, it may protect against these conditions.
Contrary to popular belief, creatine does not increase your risk of cramps and dehydration. In fact, may reduce your risk of these conditions.
Research has thoroughly documented that creatine supplements cause a quick increase in body weight.
In a study, 1 week of high dose loading of creatine supplementation (20 grams/day) increased participants’ body weight by around 2–6 pounds (1–3 kg) (
Over the long term, studies show that body weight may continue to increase to a greater extent in creatine users than in people who do not take creatine. This weight gain is due to increased muscle growth — not increased body fat (
Weight gain from creatine is not due to gaining fat but increased water content in your muscles.
However, the fact that creatine raises creatinine levels does not mean that it is harming your liver or kidneys (
To date, no study of creatine use in healthy individuals has provided evidence of harm to these organs (
A long-term study of college athletes found no side effects related to liver or kidney function. Other studies measuring biological markers in the urine found no difference after creatine ingestion (
One of the longest studies to date — lasting for 4 years — similarly concluded that creatine has no negative side effects (
But this single case study is insufficient evidence. Numerous other factors, including additional supplements, were also involved (
That said, use caution when it comes to taking creatine supplements if you have a history of liver or kidney concerns. A healthcare professional can help you decide whether taking creatine is right for you.
Current research suggests that creatine does not cause liver or kidney issues.
As with many supplements or medications, excessive doses may cause digestive issues.
In a 2008 study, a 5-gram dose (taken twice per day) caused diarrhea in 29% of participants, which was not significantly different than the placebo. However, a 10-gram dose (taken once per day) increased diarrhea risk by 56% (
Despite anecdotal reports, there is no evidence that creatine causes digestive concerns when taken at recommended doses (
It is recommended that you purchase a trusted, high quality product.
Creatine does not increase digestive issues when the recommended dosages and loading guidelines are followed.
Some research has demonstrated that creatine may help your skin by improving skin wrinkles, aging, and damage when used topically (
There is no current research to suggest creatine directly causes acne. In fact, some studies show that it can help with wrinkles, aging, and skin damage.
As with any diet or supplement regimen, it is best to discuss your creatine plans with a doctor or other healthcare professional before you start.
You may also wish to avoid creatine supplements if you take any medications that affect liver or kidney function.
Creatine may interact with certain medications, so check with your doctor before starting supplementation.
You should also consult a healthcare professional if you are pregnant or nursing or if you have a serious condition, such as heart disease or cancer.
Creatine may cause concerns if you take certain types of medications, including medications that affect blood sugar.
Some people suggest that creatine can lead to compartment syndrome, a condition that occurs when excessive pressure builds inside an enclosed space — usually within arm or leg muscles.
Although one study found increased muscle pressure during 2 hours of heat training, this resulted mainly from heat and exercise-induced dehydration — not from creatine (
Researchers also concluded the pressure was short-lived and insignificant.
Some claim that creatine supplements increase your risk of rhabdomyolysis, a condition in which muscle breaks down and leaks proteins into your bloodstream. However, this idea is not supported by any evidence.
The myth originated because a marker in your blood called creatine kinase increases with creatine supplements (
This slight increase is quite different from the large amounts of creatine kinase associated with rhabdomyolysis. Interestingly, some experts even suggest creatine may protect against this condition (
Some people also confuse creatine with anabolic steroids, but this is yet another myth. Creatine is a completely natural and legal substance found in your body and in foods — such as meat — with no link to steroids (
Finally, there is a misconception that creatine is suitable only for male athletes. Yet no research suggests that it is unsuitable in recommended doses for women or older adults (
Unlike most supplements, creatine has been given to children as a medical intervention for certain conditions, such as neuromuscular disorders or muscle loss.
Research has consistently confirmed creatine’s excellent safety profile. There is no evidence that it causes adverse conditions like rhabdomyolysis or compartment syndrome.
Creatine has been used for more than a century, and hundreds of studies support its safety and effectiveness.
It also provides many benefits for muscle and performance, may improve markers of health, and is being used in medical settings to help treat various diseases.
Creatine is one of the cheapest, most effective, and safest supplements available.