Creatine for Athletes: Benefits, Dosage and Is It Safe?

Most sports supplements promise a lot and deliver very little. Creatine is the exception. It's cheap, it's been studied for over 30 years in hundreds of trials, and it reliably helps athletes in sports that involve short, hard, repeated efforts.

It also attracts more myths than almost any other supplement. People worry it damages kidneys, causes hair loss, makes you bloated or counts as a steroid. Most of these worries don't hold up.

This guide explains what creatine is, how it works, who benefits and who doesn't, how much to take, whether to load, and what the research actually says about safety and side effects.

What is creatine?

Creatine is a natural compound made in your liver and kidneys from amino acids. You also get it from food, mainly meat and fish. Around 95% of the creatine in your body is stored in your muscles, mostly as phosphocreatine.

Phosphocreatine is a rapid energy reserve. During very intense efforts, such as a sprint, a heavy lift or a jump, your muscles need energy faster than other systems can supply it. Phosphocreatine regenerates ATP, your cells' energy currency, almost instantly. But stores are small, and they run low after about 10 seconds of maximal effort.

Taking creatine as a supplement increases these stores, typically by around 20 to 40%, depending on how much you had to begin with. Larger stores mean more energy for repeated short efforts and faster recovery between them.

What does creatine do for athletes?

The International Society of Sports Nutrition's 2017 position stand, led by Richard Kreider, describes creatine monohydrate as the most effective nutritional supplement available for increasing high-intensity exercise capacity and lean body mass during training.

The main benefits:

• More reps and more power in repeated high-intensity efforts, such as sprints, lifts and jumps.
• Greater strength gains from resistance training. A 2017 meta-analysis by Charlotte Lanhers and colleagues found that creatine increased upper-body strength more than placebo.
• More lean mass over weeks of training, partly from water stored in muscle and partly from being able to train harder.
• Faster recovery between repeated efforts, for example between sprints in team sports.

Who benefits most?

Endurance athletes may still benefit indirectly: creatine can help them handle harder interval and strength sessions, and some research suggests it helps with glycogen storage. But for pure endurance performance on race day, the effect is small.

How much creatine should you take?

There are two common approaches. Both end up in the same place.

Option 1: daily dose

Take 3 to 5 g of creatine monohydrate every day. Muscle stores rise gradually and are fully topped up after about three to four weeks.

Option 2: loading phase

Take about 20 g a day, split into four doses of 5 g, for 5 to 7 days, then drop to 3 to 5 g a day. This fills muscles in about a week.

The evidence for both comes from a classic 1996 study by Eric Hultman and colleagues. Men who took 20 g a day for six days reached high muscle creatine levels quickly. Another group who took 3 g a day reached similar levels after 28 days. Once stores were full, 2 g a day was enough to keep them there.

Loading is useful if you want the benefit quickly, for example before a competition block. If you're not in a hurry, the daily dose avoids the stomach upset some people get from 20 g a day.

Which type of creatine?

Creatine monohydrate is the form used in almost all the research. It's cheap, effective and well studied. Other forms (creatine HCl, buffered creatine, creatine ethyl ester and so on) are more expensive and haven't been shown to work better. Micronised monohydrate dissolves more easily but works the same way.

Does timing matter?

Not much. Some studies suggest a small advantage to taking it close to training, particularly afterwards, but the difference is minor. Taking it with a meal that contains carbohydrate and protein may slightly improve uptake. The most important thing is taking it every day.

Is creatine safe?

For healthy people, the research is reassuring. The ISSN position stand concludes that short- and long-term use of creatine monohydrate at recommended doses is safe and well tolerated in healthy individuals. A 2021 review by Jose Antonio and colleagues addressed common misconceptions directly and reached the same conclusion.

Kidneys

Creatine raises levels of creatinine in the blood, a waste product doctors use as a marker of kidney function. This can make kidney tests look worse even though the kidneys are fine. Controlled studies in healthy people haven't found kidney damage from creatine at normal doses.

If you take creatine and have a blood test, tell your doctor. If you have existing kidney disease, don't take creatine without medical advice.

Liver

There's no good evidence that creatine harms the liver in healthy people at recommended doses.

Hair loss

This myth comes from a single small 2009 study in rugby players, which found a rise in dihydrotestosterone (DHT), a hormone linked to male pattern baldness. That study didn't measure hair loss, and the finding hasn't been replicated. Antonio and colleagues' 2021 review concluded that current evidence doesn't show creatine causes hair loss.

Dehydration and cramping

Early concerns that creatine would cause cramps or heat illness haven't been supported. Several studies have found no increase, and some found fewer cramps and heat problems in creatine users.

Weight gain and bloating

Creatine draws water into muscle cells, so most people gain about 1 to 2 kg in the first week or two, mostly water stored inside the muscle rather than under the skin. Loading doses are more likely to cause stomach discomfort; splitting doses or skipping the loading phase usually solves it.

Is it a steroid?

No. Creatine is a naturally occurring compound found in food. It's not a hormone, and it's not on the World Anti-Doping Agency's prohibited list.

Creatine myths and facts

Creatine for women

Women tend to have lower natural creatine stores and often eat less meat, so they may see meaningful benefits. Research in women shows similar improvements in strength and high-intensity performance, often with less water weight gain than in men. Interest is also growing in creatine's role in bone and muscle health around menopause, though that research is still developing.

Creatine for vegetarians and vegans

Because dietary creatine comes mainly from meat and fish, vegetarians and vegans usually have lower muscle stores. They often see a larger response to supplementation. Most creatine monohydrate is made synthetically, so it's generally suitable for vegans, but check the capsule material if you use capsules.

Creatine for older adults

Combined with strength training, creatine may help older adults gain more strength and muscle than training alone. This matters because muscle loss with age affects mobility and independence. As always, check with a doctor if you have a medical condition or take regular medication.

Creatine and the brain

Your brain also uses creatine for energy. A 2018 systematic review by Konstantinos Avgerinos and colleagues found that creatine supplementation may improve short-term memory and reasoning in healthy people, with clearer effects in older adults and under stress, such as sleep deprivation. The evidence is still limited, and it's not a reason on its own to take creatine, but it's an interesting area of research.

What to expect, week by week

Creatine doesn't work like caffeine. You won't feel a buzz before a session. Its effects come from fuller energy stores, which help you train a little harder over weeks and months.

What happens when you stop?

When you stop taking creatine, muscle stores gradually return to normal over about four to six weeks. The extra water weight usually goes as well. You keep the strength and muscle you built through training, although your capacity for repeated high-intensity efforts returns to your previous baseline. There's no "crash" and no evidence that stopping causes your body to produce less creatine long term.

Creatine and caffeine

Some early studies suggested caffeine might cancel out creatine's benefits. More recent research hasn't found a consistent problem when both are used normally, for example with a coffee in the morning. If you use both, there's no need to change your coffee habits. Some people who are sensitive to stomach upset prefer to take them at different times.

Creatine for team-sport players during the season

For team-sport players, creatine is often most useful in pre-season, when training is heavy and focused on strength and repeated sprints. During the season, a daily maintenance dose keeps stores topped up, which may help in matches with lots of repeated high-intensity efforts. If you play in a sport where every kilogram matters, such as a weight-class combat sport, plan creatine use well away from weigh-ins.

Who should avoid creatine or check first?

• People with kidney disease or reduced kidney function.
• People taking medicines that affect the kidneys.
• Pregnant or breastfeeding women, because there's limited research.
• Under-18s, unless advised by a doctor or sports dietitian.
• Anyone with a medical condition who is unsure. Ask your doctor.

Choosing a creatine product

• Pick creatine monohydrate. Plain, unflavoured powder is usually cheapest.
• Look for third-party testing if you compete under anti-doping rules. Supplements can be contaminated with banned substances.
• Ignore blends that add creatine to pre-workout products in small or undisclosed amounts.
• Check the dose per scoop. Some scoops are 3 g, some 5 g.

Should you take creatine?

Creatine is worth considering if:

• You do strength training, sprint work or a sport with repeated high-intensity efforts.
• You want to build strength and muscle.
• You eat little or no meat or fish.
• You're an older adult doing strength training.

It's less likely to help if your training is almost all steady endurance work, or if you're in a weight-class sport close to competition, where the water weight matters.

And it won't replace the basics. Creatine works best on top of good training, enough protein and enough total food. Our guides to protein needs and interval training cover two of the things creatine supports.

If you're under 18, pregnant, breastfeeding, or have kidney disease or any other medical condition, talk to a doctor or registered dietitian before taking creatine.

Frequently asked questions

Sources and further reading

1. Kreider RB, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 2017;14:18. DOI PubMed
2. Antonio J, et al. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? Journal of the International Society of Sports Nutrition, 2021;18(1):13. DOI PubMed
3. Hultman E, et al. Muscle creatine loading in men. Journal of Applied Physiology, 1996;81(1):232-7. DOI PubMed
4. Lanhers C, et al. Creatine Supplementation and Upper Limb Strength Performance: A Systematic Review and Meta-Analysis. Sports Medicine, 2017;47(1):163-173. DOI PubMed
5. Avgerinos KI, et al. Effects of creatine supplementation on cognitive function of healthy individuals: A systematic review of randomized controlled trials. Experimental Gerontology, 2018;108:166-173. DOI PubMed