Creatine is a popular supplement that athletes use to build muscle and improve performance. Many people worry it might cause cancer, hurt their kidneys, or cause other health problems. Scientists reviewed all the current research on creatine safety and found good news: when used properly, creatine appears to be safe for most healthy people. The research doesn’t support fears about cancer or kidney damage in people with healthy kidneys. However, people with existing kidney problems or pregnant women should talk to their doctor first, since there isn’t enough research on these groups yet.

The Quick Take

  • What they studied: Scientists looked at all the research about whether creatine supplements are safe and whether the common worries people have about creatine are actually true.
  • Who participated: This was a review of existing studies, so it didn’t involve new participants. Instead, scientists examined research that other scientists had already done on creatine safety.
  • Key finding: Creatine monohydrate (the most common type) appears to be safe for healthy people when used as directed. The research doesn’t support common fears about cancer, kidney damage, dehydration, or muscle cramps.
  • What it means for you: If you’re a healthy person considering creatine, the science suggests it’s likely safe to use. However, if you have kidney problems, are pregnant, or have other health conditions, you should talk to your doctor before taking it.

The Research Details

This was a review article, which means scientists didn’t do a new experiment themselves. Instead, they carefully read through many existing studies about creatine safety and looked for patterns in what the research showed. They examined studies about different safety concerns: cancer risk, kidney function, dehydration, muscle cramps, and stomach problems. By looking at all this research together, they could see what the overall evidence actually supports and what concerns might be based on fear rather than facts.

This type of review is useful because it helps sort through lots of conflicting information. Instead of relying on one study or one person’s opinion, scientists can see what the majority of research shows. They looked at both theoretical concerns (things that could happen in theory) and actual results from real studies with real people.

Reviews like this are important because they help separate real health risks from myths. Many people have heard scary stories about supplements, but not all of those stories are backed by science. By carefully examining all the available evidence, scientists can give people accurate information to make good decisions about their health.

This review was published in Frontiers in Nutrition, a respected scientific journal. The authors looked at current scientific evidence rather than just opinions. However, because this is a review of other studies rather than a new study itself, the quality depends on which studies they included and how carefully they evaluated them. The review acknowledges where evidence is weak or missing, which is a sign of honest science.

What the Results Show

The research shows that creatine does not appear to cause cancer. While scientists have theorized that creatine could form cancer-causing compounds, actual studies in humans don’t support this concern. For kidney health, studies consistently show that creatine doesn’t damage the kidneys of healthy people. This is important because kidney damage is one of the biggest fears people have about creatine.

Regarding dehydration and muscle cramps, the evidence is actually positive for creatine users. Controlled studies (the most reliable type) show that creatine doesn’t cause dehydration or increase muscle cramps. In fact, some research suggests creatine might actually help prevent muscle cramps and help the body maintain proper temperature during exercise.

The only side effect that appears real is stomach upset, but this is dose-dependent, meaning it only happens at high doses and not everyone experiences it. Most people who follow recommended doses don’t have this problem.

The review notes that creatine may actually have some benefits beyond just muscle building. It appears to help with maintaining body temperature during exercise and may reduce muscle cramps, which are bonuses for athletes. The research also shows that individual responses to creatine vary—some people experience minor stomach issues while others have no problems at all.

This review confirms what many previous studies have suggested: creatine is safer than many people think. Over the past 20+ years, as creatine has become more popular, scientists have studied it extensively. This review brings together that body of research and shows that the safety concerns haven’t been proven by evidence. The findings align with what major sports medicine organizations have concluded about creatine safety.

The biggest limitation is that some populations haven’t been well-studied. People with kidney disease, pregnant women, and children have limited research available, so scientists can’t say for certain whether creatine is safe for these groups. The review also notes that most studies have looked at creatine monohydrate specifically, so other forms of creatine might have different safety profiles. Additionally, most research has focused on short-term use, so very long-term effects aren’t fully understood.

The Bottom Line

For healthy adults: Creatine monohydrate appears safe when used at recommended doses (typically 3-5 grams per day after an optional loading phase). The evidence supports this with high confidence. For people with kidney disease, pregnant women, or those taking medications: Talk to your doctor before using creatine, as research is limited in these groups. For children and teenagers: More research is needed, so consult a healthcare provider.

Athletes and people interested in building muscle should care about this research because it addresses their safety concerns. People with kidney problems or who are pregnant should care because they need to be cautious. Parents of young athletes should care because they need accurate information to make decisions for their children. Anyone considering creatine should read this to understand the actual risks versus imagined ones.

Creatine doesn’t work overnight. Most people start noticing effects on muscle performance and size within 1-2 weeks, with more noticeable changes over 4-8 weeks. The safety profile is established relatively quickly—if someone is going to have stomach issues, they usually notice within the first few days.

Want to Apply This Research?

  • Track daily creatine intake (in grams) and note any side effects like stomach discomfort, energy levels, and workout performance. This helps users see if creatine is working for them and if they’re experiencing any issues.
  • Users can set a daily reminder to take their creatine dose at the same time each day, ideally with food and plenty of water. This builds consistency, which is important for creatine to work effectively.
  • Over 4-8 weeks, track changes in muscle strength, workout performance, and body composition. Also monitor for any side effects. Users can rate how they feel overall and note any changes in energy or recovery. This long-term tracking helps users decide if creatine is right for them.

This review summarizes scientific research on creatine safety but is not medical advice. Individual responses to supplements vary. People with kidney disease, pregnant women, nursing mothers, children, and those taking medications should consult their healthcare provider before using creatine or any supplement. This information is for educational purposes and should not replace professional medical guidance. Always follow product label instructions and talk to a doctor if you experience unusual symptoms.