- What is creatine?
- Side effects
- How it works
- Dehydration and cramps
- Weight gain
- Kidneys and liver
- Drug interaction
- Other effects
What is creatine? Is it bad for you?
Creatine is the top sports performance supplement available. Yet despite its research-backed benefits, some people avoid creatine because they worry it’s terrible 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.
Purported side effects of creatine
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?
Some people wrongly claim that creatine is an anabolic steroid, that it’s unsuitable for women or teenagers, or that it should be used only by professional athletes or bodybuilders.
Despite this negative press, the International Society of Sports Nutrition regards creatine as highly safe, concluding that it is one of the most beneficial sports supplements available.
One study examined 69 health markers after participants took creatine supplements for 21 months. It found no adverse results.
Creatine has also been used to treat various diseases and health concerns, including neuromuscular disorders, concussions, diabetes, and muscle loss.
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.
Research has shown positive health benefits in athletes who took daily supplements of creatine for long periods.
Summary: Although some people make false claims about creatine’s side effects and safety issues, none of them are supported by research.
How does creatine work biologically?
Creatine is found throughout your body, with 95% of it stored in your muscles.
It is obtained from meat and fish and can also be produced naturally in your body from amino acids.
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.
During high-intensity exercise, the stored creatine helps your muscles produce more energy. This is the main reason that creatine enhances exercise performance.
Once you fill your muscle’s creatine stores, any extra is broken down into creatinine, which is metabolized by your liver and released into your urine.
Summary: Around 95% of the creatine in your body is stored in your muscles. There, it provides increased energy for high-intensity exercise.
Does creatine cause dehydration or cramps?
Creatine alters your body’s stored water, driving additional water into your muscle cells.
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. They also missed fewer sessions due to illness or injury.
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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 crucial role in muscle cramps.
The most conclusive research has been conducted on 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.
Summary: Contrary to popular belief, creatine does not increase your risk of cramps and dehydration. In fact, it may reduce your risk of these conditions.
Does creatine cause weight gain?
Research has thoroughly documented that creatine supplements cause a quick increase in body weight.
In a study, one 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 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.
Increased muscles may also have benefits for older adults, individuals with obesity, and those with certain diseases.
Summary: Weight gain from creatine is not due to gaining fat but increased water content in your muscles.
How does creatine affect your kidneys and liver?
Creatine can slightly raise levels of creatinine in your blood. Creatinine is commonly measured to diagnose kidney or liver conditions.
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However, the creatine raises creatinine levels does not mean it harms 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 most extended studies to date — lasting for four years — similarly concluded that creatine has no adverse side effects.
Another famous study often cited in the media reported kidney disease in a male weightlifter supplemented with creatine.
But this single case study is insufficient evidence. Numerous other factors, including additional supplements, were also involved.
That said, use caution when 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.
Summary: Current research suggests that creatine does not cause liver or kidney issues.
Does creatine cause digestive concerns?
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 daily) increased diarrhea risk by 56%.
For this reason, the recommended serving is set at 3–5 grams. The 20-gram loading protocol is split into four servings of 5 grams each over a day.
Despite anecdotal reports, there is no evidence that creatine causes digestive concerns when taken at recommended doses.
It is possible that additives, ingredients, or contaminants generated during the industrial production of creatine can lead to issues.
It is recommended that you purchase a trusted, high-quality product.
Summary: Creatine does not increase digestive issues when followed by the recommended dosages and loading guidelines.
Does creatine give you acne?
There is no evidence that creatine causes acne. Creatine may enhance your ability to exercise harder and longer, leading to increased sweat. While sweating can lead to acne, creatine itself does not.
Some research has demonstrated that creatine may help your skin by improving skin wrinkles, aging, and damage when used topically.
Summary: No current research suggests that creatine directly causes acne. Some studies show that it can help with wrinkles, aging, and skin damage.
How does creatine interact with other drugs?
As with any diet or supplement regimen, discussing your creatine plans with a doctor or other healthcare professional before you start is best.
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.
Creatine can help improve blood sugar management, so if you use medication known to affect blood sugar, you should discuss creatine use with a doctor.
You should also consult a healthcare professional if you are pregnant or nursing or have a serious condition, such as heart disease or cancer.
Summary: Creatine may cause concerns if you take certain types of medications, including medications that affect blood sugar.
Other potential side effects of creatine
Some suggest that creatine can lead to compartment syndrome, where 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 where 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 differs from the amounts of creatine kinase associated with rhabdomyolysis. Interestingly, some experts even suggest creatine may protect against this condition.
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Some people also confuse creatine with anabolic steroids, but this is yet another myth. Creatine is a natural and legal substance found in your body and 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 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.
Studies lasting as long as three years have found no adverse effects of creatine in children.
Summary: 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 over a century, and hundreds of studies support its safety and effectiveness.
It also provides many benefits for muscle and performance, may improve health markers, and is used in medical settings to help treat various diseases.
Creatine is one of the cheapest, most effective, and safest supplements.