Creatine: The Complete, Science-Backed Guide

Creatine is the most researched supplement in sport, and one of the few with consistent evidence that it works. It is also cheap. Yet it still comes with a cloud of myths about kidneys, hair loss and water weight. Here is what the research actually says, and exactly how to take it.

What is creatine?

Creatine is a compound your body makes and stores, mostly in your muscles. According to the International Society of Sports Nutrition (ISSN), you use and need to replace about 1-3 g a day. Around half of that comes from food, mainly meat and fish, and the rest is made in your liver and kidneys from amino acids. For context, a pound (about 450 g) of raw beef or salmon contains about 1-2 g.

Inside your muscles, creatine is stored as phosphocreatine. During short, hard efforts like a heavy set or a sprint, it helps your muscles quickly regenerate ATP, the molecule they use for energy. More creatine in the tank means you can produce a little more work before you tire, rep after rep and session after session.

What creatine does for you

The ISSN position stand concludes that creatine supplementation raises the creatine stored in your muscles, which helps explain the improvements seen in high-intensity exercise performance and the bigger gains from training over time. A review of 22 studies put numbers on it:

Creatine does not do the training for you. It helps you get a little more out of every session, and that adds up.

• Older adults. A meta-analysis of older adults found that creatine taken alongside resistance training led to more lean mass, greater gains on the chest press and leg press, and better performance on a chair-stand test than training alone.
• Vegetarians and vegans. They tend to have lower creatine stores in their muscles, because they eat little or none from food, so they may see bigger gains from supplementing.
• Your brain. A 2024 meta-analysis found creatine may improve memory, attention and processing speed, but the certainty of the evidence was only moderate to low. Promising, but not a reason to buy it on its own.

How much creatine to take

There are two ways to fill your muscles with creatine. Both get you to the same place; one just gets there faster.

For a 70 kg person, loading works out at roughly 20 g a day, as four 5 g servings. A 2021 review by ISSN researchers concluded that a loading phase is not required: 3-5 g a day works on its own, it just takes longer to reach full stores. If you want the simplest option, skip loading and take 5 g a day.

When to take creatine

Whenever you will remember. Creatine works by gradually topping up your stores, not by giving you a boost on the day, so taking it consistently matters far more than timing.

One small study of 19 recreational bodybuilders compared 5 g taken just before or just after training for four weeks. The after-training group looked slightly better, but the difference between groups was not statistically significant. Taking it after training is fine if it suits you; it is not something to stress about.

Which creatine to buy

Buy creatine monohydrate. The ISSN describes it as the most extensively studied and clinically effective form, and concludes that claims about other forms being better absorbed are unfounded. Fancier versions, such as creatine HCl or ethyl ester, cost more without being proven better.

Because supplements are regulated as food in the UK, choose a product that is batch-tested by a third party, such as one certified by Informed Sport. That matters most if you are drug tested in your sport.

Creatine myths, checked against the research

"Creatine damages your kidneys"

Not in healthy people. The ISSN found no compelling evidence that creatine harms kidney function, and its review concluded that at the recommended doses it does not cause kidney damage in healthy individuals. A 2025 meta-analysis found creatine can cause a small, temporary rise in creatinine on a blood test, while kidney filtration itself did not change. So if you have blood tests, tell your doctor you take it. If you already have a kidney condition, speak to your GP before you start.

"Creatine causes hair loss"

This myth traces back to one small 2009 study in rugby players that found a rise in DHT, a hormone linked to male pattern baldness. It did not measure hair, and its findings have not been repeated. In 2025, a 12-week randomised controlled trial gave resistance-trained men 5 g of creatine or a placebo every day and measured both hormones and hair directly. Creatine made no difference to DHT or to any measure of hair loss.

"It is just water weight"

Partly true at the start. Weight gain is the most consistently reported side effect of creatine, and loading can cause short-term fluid retention of around 0.5-1 litre. That water is held in your muscles, not under your skin. Over weeks of training, the extra work you can do adds up to real gains in strength and lean mass.

"Creatine is a steroid"

No. Creatine is not an anabolic steroid or a hormone. It is a compound found in food and made by your own body, and the ISSN notes that it is not banned by any sport organisation.

"You need to cycle it" and "it causes cramps"

Neither holds up. The ISSN position stand reports that both short and long-term use, including studies of up to five years, is safe and well tolerated in healthy people, so there is no need to take breaks. The 2021 review also concluded that creatine does not cause dehydration or muscle cramps.

Who should take creatine?

Creatine is most useful if you lift weights or play a sport built on short, hard efforts, such as football, rugby or sprinting. It is especially worth considering if you are vegetarian or vegan, or if you are older and training to hold on to muscle. The benefit for long, steady endurance exercise is smaller.

Creatine is one of only a handful of supplements with strong evidence behind it. To see how it compares with the rest, read our guide to which supplements actually work.

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