Short answer
Creatine is the most researched supplement in sport, and one of very few with strong evidence behind it. Taking 3 to 5 grams of creatine monohydrate a day helps you do more work in each set, which over time means more strength and muscle than training alone. It works best for people who lift or sprint, and especially for vegetarians and adults over 50. In healthy people it is safe, and the common worries about hair loss, kidneys and bloating are not supported by the research.
Most supplements on a gym shop shelf have little evidence behind them. Creatine is the exception. Hundreds of studies over more than 30 years have looked at what it does, and the International Society of Sports Nutrition (ISSN) calls it the most effective supplement available for increasing high-intensity exercise capacity and lean body mass.
This guide covers what creatine does, who gets the most from it, how to take it, and which of the common worries hold up. If you are taking it on a trip, our guide to flying with creatine and buying it abroad covers the practical side.
What creatine is and how it works
Creatine is a compound your body makes from three amino acids, mostly in the liver and kidneys. You also get it from meat and fish. About 95% of it is stored in your muscles, mainly as phosphocreatine.
When you do something short and hard, like a heavy set of squats or a sprint, your muscles burn through their immediate energy supply (ATP) in seconds. Phosphocreatine rebuilds that ATP quickly, so it is what lets you keep going for those few extra seconds.
A normal diet leaves your muscle creatine stores about 60 to 80% full, according to the ISSN. Supplementing fills them, which typically lets you squeeze out an extra rep or two per set and recover a little faster between sets. One extra rep is not much on its own. Across months of training, the extra work adds up.
What the research shows it does
Strength and power
This is the best-established benefit. A 2003 meta-analysis by Branch, covering about 100 studies, found creatine improved performance in short, high-intensity efforts, especially repeated efforts. A 2017 meta-analysis by Lanhers and colleagues found it increased upper-body strength in exercises like the bench press, and an earlier analysis by the same group found the same for the lower body.
Muscle growth
Taken alongside resistance training, creatine leads to more gains in lean mass than training alone. Part of the early gain is water drawn into the muscle cells. The longer-term gain is real muscle, built because you can train harder. The effect is modest: think of it as making good training a little more effective, not replacing it.
Older adults
From about the age of 50, people lose muscle and strength faster. A 2014 meta-analysis by Devries and Phillips found that older adults who combined creatine with resistance training gained more muscle and strength than those who trained alone. Without the training, creatine on its own does little.
The brain
Your brain also uses creatine for energy. A 2018 systematic review by Avgerinos and colleagues found that creatine may improve short-term memory and reasoning, with the clearest effects in older adults and in situations that stress the brain, such as sleep deprivation. The research is promising but still early, and you should not take creatine for this reason alone.
Who should take it
| Who | Evidence | Why |
|---|---|---|
| Anyone lifting weights | Strong | More strength and muscle from the same training |
| Vegetarians and vegans | Strong | Lower starting stores, so a bigger rise when supplementing |
| Adults over 50 | Good | Helps training slow age-related muscle and strength loss |
| Women | Good | Same training benefits as men; research on other benefits is growing |
| Sprint and team-sport athletes | Good | Better repeated short, hard efforts |
| Endurance-only athletes | Weak | Little benefit for steady efforts; may add a little body weight |
Vegetarians and vegans
Creatine is found almost only in meat and fish, so people who do not eat them start with lower stores. In a 2003 study by Burke and colleagues, vegetarians who supplemented had a larger rise in muscle creatine, and larger gains in lean mass, than meat eaters. If you do not eat meat, creatine is likely to be one of the most useful supplements you can take.
Women
Much of the early research was on men, which led to a myth that creatine is a men's supplement. Reviews since, including one by Smith-Ryan and colleagues in 2021, find women get the same training benefits. Researchers are now looking at whether it helps around menopause, when muscle and bone loss speed up.
Who should be careful
Ask a doctor first if you have kidney disease, are pregnant or breastfeeding, are under 18, or take medicines that affect the kidneys. Endurance athletes who only do steady efforts, such as marathon runners, get little benefit, and the extra kilo or two of water weight could slow them down.
How to take it
- Form: creatine monohydrate. It is what the research uses, and no other form has been shown to work better.
- Dose: 3 to 5 grams a day. A classic study by Hultman and colleagues in 1996 found 3 grams a day fills your muscles in about 28 days.
- Loading (optional): about 20 grams a day, split into four doses, for five to seven days fills your muscles in a week. Then drop to 3 to 5 grams. It works faster but is more likely to upset your stomach.
- Timing: any time of day. Taking it every day matters far more than when.
- Quality: buy a product tested by a third party, such as Informed Sport, especially if you are tested for drugs in your sport.
Creatine is cheap. A 500 g tub lasts more than three months at 5 grams a day. You do not need a branded product with added extras.
Travelling? Because the benefit comes from keeping your muscles full, a few missed days make almost no difference: your stores take weeks to drop. You can pack it in your hold luggage or buy it when you land. See what supplements you can take through airport security.
The myths, and what the evidence says
A 2021 paper in the Journal of the International Society of Sports Nutrition, "Common questions and misconceptions about creatine supplementation" by Antonio and colleagues, went through the most common worries one by one. Here is what it and other research found.
| The claim | What the research says |
|---|---|
| It causes hair loss | One 2009 study in 20 rugby players found a rise in DHT, a hormone linked to hair loss. It measured no hair and has not been replicated; reviews find no evidence that creatine causes hair loss. |
| It damages your kidneys | Long-term studies in healthy people show no harm. It can raise creatinine on a blood test, which can look like a kidney problem, so tell your doctor you take it. If you have kidney disease, ask first. |
| It makes you bloated | The extra weight, usually 1 to 2 kg in the first weeks, is mostly water drawn into the muscle, not under the skin. Skipping the loading phase makes it less noticeable. |
| It is a steroid | No. It is a compound your body makes from amino acids and you eat in meat and fish. It is allowed in every sport. |
| You need to cycle it | There is no evidence that stopping and starting helps. Your body does not stop making its own creatine permanently. |
| It causes cramps and dehydration | Studies in athletes training in the heat have found no increase, and some found fewer cramps. |
The bottom line: if you train with weights or play a sport with short, hard efforts, creatine monohydrate at 3 to 5 grams a day is cheap, safe for healthy people, and one of the few supplements that reliably does what it claims. It will not replace training, sleep or protein, but it makes all three a little more effective.
Sources
- Kreider RB et al. (2017). 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.
- Antonio J et al. (2021). Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? Journal of the International Society of Sports Nutrition.
- Branch JD (2003). Effect of creatine supplementation on body composition and performance: a meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism.
- Lanhers C et al. (2017). Creatine supplementation and upper limb strength performance: a systematic review and meta-analysis. Sports Medicine.
- Devries MC, Phillips SM (2014). Creatine supplementation during resistance training in older adults: a meta-analysis. Medicine & Science in Sports & Exercise.
- Avgerinos KI et al. (2018). Effects of creatine supplementation on cognitive function of healthy individuals: a systematic review of randomized controlled trials. Experimental Gerontology.
- Burke DG et al. (2003). Effect of creatine and weight training on muscle creatine and performance in vegetarians. Medicine & Science in Sports & Exercise.
- Smith-Ryan AE et al. (2021). Creatine supplementation in women's health: a lifespan perspective. Nutrients.
- Hultman E et al. (1996). Muscle creatine loading in men. Journal of Applied Physiology.
- van der Merwe J et al. (2009). Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players. Clinical Journal of Sport Medicine.
Frequently asked questions
What does creatine actually do?
Creatine tops up the phosphocreatine stored in your muscles, which your body uses to make energy quickly during short, hard efforts like a heavy set or a sprint. With fuller stores you can do a rep or two more per set. Over weeks of training, that extra work adds up to more strength and muscle than training alone.
Who should take creatine?
Anyone who lifts weights or does sports with short, hard efforts will probably benefit. Vegetarians and vegans tend to see the biggest effect, because they get little or no creatine from food. Adults over 50 are another group with strong evidence, as creatine combined with strength training helps counter muscle loss with age.
How much creatine should I take a day?
3 to 5 grams of creatine monohydrate a day. Your muscles fill up in about three to four weeks. If you want them full in a week, take about 20 grams a day split into four doses for five to seven days, then drop to 3 to 5 grams. Larger people may need the upper end.
Does creatine work for women?
Yes. Women get the same training benefits as men: more strength and lean mass alongside resistance training. Researchers are also studying benefits around menopause, pregnancy and mood, though that evidence is earlier. The water weight is usually small and fades once your muscles are saturated.
When is the best time to take creatine?
Whenever you will remember. Timing matters far less than taking it every day, because the benefit comes from keeping your muscles saturated. Some studies suggest a small advantage to taking it around training, but the difference is minor. Mixing it with a meal can help if it upsets your stomach.
Which type of creatine is best?
Creatine monohydrate. It is the form used in almost all the research, it is cheap, and no other form, such as creatine HCl or buffered creatine, has been shown to work better. Look for a product that is independently tested for purity, such as Informed Sport certified.
What happens if I stop taking creatine?
Your muscle creatine slowly returns to normal over about four to six weeks, and you lose the water weight. You keep the muscle you built, as long as you keep training. Missing a few days, for example on a trip, makes almost no difference.
The supplement works if the training does
Creatine only helps if you keep lifting. GymMaps finds gyms wherever you are, with day pass prices, real photos and the equipment each one has, so you never have to skip a session on the road.
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