Creatine: The science behind the gym supplement with benefits for both brain and body

Creatine is one of the most widely studied performance-enhancing substances in the world. Once dismissed as just a bodybuilding supplement, its public popularity has grown hand-in-hand with interest from scientists.

The supplement is generally associated with improved strength and muscle mass, but evidence suggests that it actually has a role in everything from growth in children and adolescents to brain health.

“After 20 [to] 30 years of research on physical performance, we’ve noticed a lot of health benefits,” says Richard Kreider at Texas A&M University. “It’s a remarkable nutrient, which helps our cells in a variety of ways, not only for exercise performance.”

What is creatine?

It is a compound that is produced naturally in our bodies and those of other vertebrates. Primarily found in muscles, it also shows up in the brain, blood, testicles and other tissues and organs.

Our bodies synthesise creatine, with 1 to 2 grams created each day by the liver, kidneys, pancreas and the brain. People who eat protein-rich animal products get roughly the same amount from their diet.

“Any time you consume protein, those proteins are made up of amino acids, and if you put three particular amino acids together, it forms this molecule called creatine,” says Scott Forbes at Brandon University in Canada.

What does creatine do in the body?

It plays a critical role in the complicated way that our bodies produce energy at the cellular level, says Forbes. “It’s converted and stored into a molecule called phosphocreatine, which can then be broken down into energy rapidly.”

Like carbohydrates, creatine is used to produce adenosine triphosphate (ATP), which stores and supplies energy to our cells. It also seems to protect the structure and function of mitochondria, the energy powerhouses inside cells.

Forbes says creatine is particularly useful when you are stressed or if your tissues are lacking oxygen, which can be brought on by conditions such as asthma or anaemia. “Any situation when you might require more energy,” he says.

How does it affect physical performance?

Creatine has been available as a sports supplement since the early 1990s, and has long been credited for helping athletes increase their strength and speed.

There are thousands of studies to support this, says Kreider. “An athlete that has higher creatine stores will sprint faster, recover faster, do more total work – a 10 to 15 per cent improvement in performance and training adaptation. It’s not modest at all.”

Supplementing with creatine also leads to rapid increases in muscle mass, which is why it is popular among bodybuilders. “We have shown that trained athletes can have as high as a 3.5-kilogram increase in muscle mass within a 5 to 10 week period,” says Kreider. “That is profound. Compare it to a control, where somebody is just training and having a normal diet, you may gain half a kilogram per month.”

Creatine supplements may also be particularly beneficial later in life. “We recommend creatine for active ageing to reduce the decline in muscle [and] to maintain muscle performance,” says Kreider.

But researchers stress that this isn’t an elixir that can replace a healthy lifestyle. “You only really get the benefits, particularly from a muscle-growth perspective, if you combine it with exercise or resistance training,” says Forbes.

How does creatine affect the brain?

A number of papers have shown that creatine supplementation can improve aspects of cognitive performance. One small study published earlier this year found that a single dose of creatine improves memory and processing speed within 3 hours in sleep-deprived people, compared with a placebo.

But not all research has produced consistent results. In 2023, the largest randomised placebo-controlled study of creatine’s effects on cognition to date found only a small beneficial effect, equivalent to a 1 to 2.5 point increase in intelligence quotient (IQ) .

“Most of the research shows that it might impact your brain, but in young, healthy individuals, it doesn’t seem to play a big, big role unless your brain is stressed with sleep deprivation or mental fatigue,” says Forbes.

And while the research on this is still in its infancy, there may also be a protective effect against neurodegenerative conditions – for instance, people with Alzheimer’s have lower amounts of creatine in their brains – or even physical brain damage.

“For example, if you get a concussion, you basically have an ischemic event: lack of oxygen to an area of the brain that limits its ability to function and causes swelling and inflammation,” says Kreider. “We know, at least in animals fed on creatine, the concussion damage is reduced by about half.”

How does creatine impact our wider health?

Creatine works at the cellular level, so researchers believe that its positive effects could be widespread in the body. “We’re finding that increasing the energy availability in the cell is critical, especially when there’s a lot of limitations in providing energy,” says Kreider. “If you have a heart attack or stroke, for example, [creatine] reduces the size of the damage because it’s protecting those cells.”

An analysis of data from the US National Health and Nutrition Examination Survey also suggests that creatine could be beneficial for children. “Kids that grow up with less creatine in their diet have less muscle, they’re shorter and they have a higher body fat,” says Kreider. “Adolescent girls who have higher creatine have fewer menstrual cycle issues.”

He also points to studies that support the effects of creatine in strengthening bones, reducing levels of low-density lipoprotein (LDL) cholesterol and managing blood glucose, although reviews of multiple studies on the latter show inconsistent results for people with diabetes.

Who should take it?

An emerging consensus among scientists is that creatine supplementation is beneficial for pretty much everyone. Kreider predicts that, in time, this will be recommended for certain groups, including older or pregnant people, and anyone who doesn’t eat meat, fish or dairy.

He also thinks certain food will one day be fortified with creatine. “It’s going to start in the plant-based space, adding creatine to plant-based protein powders and veggie burgers, those types of things,” says Kreider. “That would offset the deficiency they may have in their diet.”

Does it matter when I take creatine?

The time of day may only matter if you are an athlete trying to win a race or beat your personal best. “We know that if you take it in close proximity to your training, the results are a little bit better,” says Forbes.

But creatine is also stored in the body as an energy reserve. “Think about endurance athletes where there’s changes in pace in a race,” says Forbes. “Suddenly somebody breaks away and you’re like, ‘whoa, how’d they do that?’ Well, they changed their power output quite substantially and I think creatine plays a role in that.”

The effects of supplementation can be relatively long lasting, but it still needs repeating. “If you stop taking creatine, it takes four to six weeks to return back to baseline,” says Forbes. “Some people will cycle on and off creatine, but there’s never been a study to compare cycling on and off versus just taking it for long periods of time.”

How should I take it?

Creatine is available in powder form, pills or gummies. In terms of efficacy, there doesn’t seem to be any difference between them, although pills and powders have been around for longer so tend to be the formulations that are tested in studies.

There are also different types of creatine available, but creatine monohydrate is the most widely available and the best studied.

Does creatine have any side effects?

The supplements are generally considered safe at the doses most people take them, which is around 5 grams a day, according to Forbes. But some people report dehydration or muscle cramps. “There are a few people that have GI [gastrointestinal] distress,” says Forbes. “They take creatine and it just doesn’t sit well in their stomachs. For those individuals, I suggest taking a lower dose of creatine.”

You may need to consult a doctor before taking supplements