Creatine Side Effects, Interactions, and What You Should Know (2024)

The majority of research suggests creatine supplementation is safe when taken at the recommended daily dose. That said, some people avoid creatine because they worry about certain myths.

Creatine is one of the most common sports performance supplements available.

Yet, despite its research-backed benefits, some people avoid creatine because they worry about potential side effects. These are thought to include:

• kidney damage
• liver damage
• kidney stones
• weight gain
• bloating
• dehydration
• hair loss
• muscle cramps
• digestive concerns
• rhabdomyolysis

A 2021 review found that many studies don’t support these side effects. In fact, creatine could help improve athletic performance, muscle mass, and recovery, among other things.

In this article, we answer common questions regarding the safety, concerns, and potential side effects of creatine.

Some people claim creatine is an anabolic steroid.

However, creatine is a substance naturally found in your body. It’s produced from the two amino acids glycine and arginine in your liver and is also found in foods like red meat and fish.

The International Society of Sports Nutrition (ISSN) regards creatine as safe and concludes it’s one of the most beneficial sports supplements available.

Creatine is found throughout your body, with 95% of it stored in your muscles.

Most of the creatine in your muscles is phosphocreatine. This contributes to the generation of adenosine triphosphate (ADT), which is the molecular source of energy for your cells.

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 kilograms (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.

Creatine supplementation could increase the production of phosphocreatine and ADT, leading to enhanced exercise performance.

Once you fill your muscle’s creatine stores, any extra is broken down into creatinine, metabolized by your liver, and excreted in urine.

Creatine alters your body’s stored water content, driving additional water into your muscle cells.

This fact may be behind the theory that creatine causes dehydration and muscle cramps.

However, this shift in cellular water content is minor, and the ISSN found that no research supports these claims.

Instead, the ISSN notes that many studies found creatine supplementation may have a hyper-hydrating effect that could help prevent dehydration and muscle cramps when exercising in hot temperatures.

Similarly, a 3-year 2003 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.

Based on the current evidence, creatine does not cause dehydration or cramping. It may even protect against these conditions.

Research has thoroughly documented that creatine supplements cause a quick increase in body weight.

This weight gain, however, is due to an increase in water weight, not fat.

A 2019 study found that taking 2 grams (g) of creatine daily and exercising twice weekly for 5 weeks helped participants ages 50 years and older lose slightly more body fat than participants who only exercised.

A 2023 review found similar results in people younger than 50 years old.

Over the long term, creatine users may continue to increase their body weight more than people who don’t take it.

However, this weight gain is due to increased muscle mass, not body fat.

Increased muscle mass may especially benefit older adults, individuals with obesity, and those with certain diseases.

Creatine can slightly raise creatinine levels in the blood. Creatinine is commonly measured to diagnose kidney or liver conditions.

However, the fact that creatine raises creatinine levels does not mean it’s harming your liver or kidneys.

A 2020 study found that taking up to 5 g of creatine daily for 35 days did not affect kidney function.

Similarly, another 2020 study found that creatine supplementation did not impact blood, urine, and metabolic markers, as well as kidney function.

A 4-year 2001 study — one of the longest studies to date — concluded that creatine supplementation has no negative side effects. Similarly, the ISSN notes that no study of creatine use in healthy individuals has provided evidence of harm to these organs.

That said, it’s still best to use caution when taking creatine supplements if you have a history of liver or kidney concerns. A healthcare professional can help you decide whether creatine is right for you.

As with many supplements or medications, excessive doses of creatine may cause digestive issues.

In a 2008 study, a 5-g dose taken twice daily caused diarrhea in 29% of participants, which was not significantly different from the placebo. However, a 10-g dose taken once daily increased diarrhea risk by 56%.

For this reason, the recommended serving is set at 3 to 5 g daily. The 20-g loading protocol is also split into 4 servings of 5 g each over a day.

Interestingly, a 2021 review found that creatine supplementation may help reduce the severity of inflammatory bowel diseases. These are usually characterized by gastrointestinal symptoms like diarrhea, abdominal pain, and bloody stools.

It’s possible that additives, ingredients, or contaminants generated during the industrial production of creatine can lead to digestive concerns.

However, no evidence suggests creatine causes digestive concerns when taken at recommended doses.

It’s recommended that you purchase a trusted, high quality product.

No evidence suggests 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.

As with any diet or supplement regimen, it’s best to speak with a healthcare professional before taking creatine. Creatine may interact with certain medications.

You may also wish to speak with a doctor if:

• you take medications that affect your liver, kidneys, or blood sugar
• you’re pregnant or nursing
• you have a serious medical condition, such as heart disease

A doctor could help you decide whether creatine is right for you.

Some people suggest creatine may lead to compartment syndrome.

A 2006 study found increased muscle pressure during 2 hours of heat training, but this resulted mainly from heat and exercise-induced dehydration, not creatine.

No research suggests that creatine supplementation leads to compartment syndrome.

Some claim that creatine supplements increase your risk of rhabdomyolysis, but no evidence supports this.

The myth originated because a marker in your blood called creatine kinase is used to help diagnose the condition.

However, the slight increase from creatine supplementation is different from the large amounts associated with rhabdomyolysis.

A 2017 review found that creatine supplementation did not cause rhabdomyolysis.

Research has shown that it is safe to consume creatine supplements daily, even over several years.

No evidence supports significant, detrimental side effects in people who consume high doses of creatine (30 g/day) for up to 5 years.

In fact, athletes who take daily creatine supplements for long periods of time experience positive health benefits.

There’s a misconception that creatine is suitable only for adult male athletes. Yet, no research suggests it’s unsuitable in recommended doses for adult females.

A 2021 review suggests creatine supplementation may have several benefits for females, such as improving:

• muscular strength, function, and performance during premenopause
• mood and mental cognition
• bone health

Studies lasting as long as 3 years have also found no negative effects of creatine in children. It’s been used as a medical intervention in children for certain conditions, such as neuromuscular disorders and muscle loss.

Creatine supplementation may provide more health benefits beyond athletic performance. A 2021 review of 1,322 articles found that creatine may help:

• lower blood lipid markers, such as cholesterol and triglyceride levels
• reduce liver fat, heart disease risk, and bone loss
• provide antioxidative benefits
• control blood sugar levels
• slow down cancer progression
• improve osteoarthritis symptoms and cognitive function

Is creatine OK to take every day?

Research suggests it’s safe to take up to 5 g of creatine every day. If you’re living with an underlying health condition, speak with a doctor about the best dosage for you.

What does creatine do to your body?

Creatine may have several benefits, such as increasing athletic performance, muscle mass, and endurance and preventing chronic diseases.

What happens if you stop taking creatine?

A 2018 review found that it could take 4 to 6 weeks for your phosphocreatine levels to return to what they were before you started taking creatine supplements. The authors also note that research is mixed on whether creatine cycling is necessary, too. One cycle is when you supplement for a period, then stop for a period.

Does creatine affect sleep?

No research has looked at how creatine affects sleep. However, some research indicates that creatine supplementation may help manage the impacts of sleep deprivation.

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 health markers, and is being used in medical settings to help treat various diseases.

Creatine is one of the cheapest, most effective, and safest supplements available.