Creatine is no longer confined to the vocabulary of the gym. This molecule, which occurs naturally in the body, is being studied for its effects on strength, ageing and even certain brain functions. But these lines of research are not all supported by the same level of evidence. This distinction is essential before considering supplementation.
What does creatine do in the body?
The body produces creatine from amino acids and also obtains it from food, mainly meat and fish. Much of it is found in the muscles, where it helps to rapidly replenish ATP, a molecule that supplies cells with energy directly.
During brief, intense exertion, such as a sprint or a set of resistance exercises, the body must regenerate ATP very quickly. Creatine stored in the form of phosphocreatine contributes to this process. It is therefore neither an anabolic hormone nor a substance foreign to the normal functioning of muscles.
The scientific fact sheet from the US National Institutes of Health notes that the value of creatine supplements depends first and foremost on the type of exercise and the training conditions.
In sport, which benefits are actually documented?
The body of trials reviewed by the NIH points to a possible effect on strength, power and the ability to repeat high-intensity efforts. A person training may therefore be able to handle more work over the course of their sessions, which can facilitate certain training adaptations.
By contrast, the benefit is far less clear for disciplines based mainly on continuous endurance, such as a long-distance run. Creatine is no substitute for technical development, sleep, diet or regular training sessions.
Responses vary between individuals and according to the method used. It is also important to distinguish a change in performance measured during a given exercise, an increase in body mass and a lasting gain in muscle tissue. These three observations are not interchangeable.
What Europe actually allows manufacturers to claim
Health claims appearing on products sold in the European Union are regulated. The consolidated version of European Regulation No 432/2012 allows a claim stating that creatine improves performance during successive bursts of short-term, high-intensity exercise, for products providing 3 grams of creatine per day and aimed at the relevant adults.
A second, more specific claim concerns adults over 55 who regularly engage in resistance training. The text specifies that creatine can enhance the effect of this training on muscle strength under defined conditions, including 3 grams per day and a progressive programme followed at least three times a week for several weeks.
These authorisations are not a universal recommendation to take creatine. They indicate the conditions under which a manufacturer may claim a specific benefit, not that this benefit is guaranteed for every person.
Gaining weight does not necessarily mean gaining the same amount of muscle
Creatine can increase body weight on the scales from the first few weeks, partly because it promotes water retention in the muscles. The NIH notes that studies have reported a body-weight increase of around 1 to 2 kilograms over one month in some situations where supplementation accompanies weight training.
This figure should not be repeated as a promise of muscle growth. To assess a genuine muscular adaptation, researchers need to distinguish water mass, overall weight, volume measurements and the force produced during standardised exercises.
The same principle applies to commercial comparisons: a ‘before and after’ photo cannot isolate the effect of the supplement from that of training, diet or changes in hydration.
What about memory or concentration?
This is the area where the gap between media enthusiasm and the conclusions reached by authorities is most evident. Research is exploring the idea that increased phosphocreatine availability in the brain could support certain demanding tasks, particularly under specific experimental conditions.
But in November 2024, the European Food Safety Authority (EFSA) concluded that the available studies did not establish a cause-and-effect relationship between creatine consumption and improved cognitive function. The opinion concerned an application for a health claim aimed at the general adult population.
The experts highlighted limitations in several trials and in the methods used to pool their results. A few signals observed at high doses on specific tasks have not been reproduced consistently enough at other doses and in other areas of cognition.
The scientific conclusion is not that every hypothesis concerning the brain has been disproved, but that it would be misleading today to sell creatine as a proven way to improve memory or concentration, or to prevent brain ageing.
In what form, and with what precautions?
Creatine monohydrate is the most widely studied form and the one used as a reference in most clinical studies. Forms sold at a higher price may claim better absorption or additional effects; these claims should be assessed through relevant direct comparisons, not just advertising messages.
Safety must also be considered in context. The NIH regards creatine as generally well tolerated by healthy adults at the doses usually studied, including over several years in some research. Reported effects mainly include weight gain related to water and, in some people, digestive discomfort.
This does not mean that taking it is appropriate at every age or in every circumstance. In the presence of kidney disease, medication use or a particular medical condition, individual medical advice is necessary. Pregnant or breastfeeding women and minors should not assume that findings from trials conducted mainly in adults apply to them.
Product quality is a separate question from the molecule’s effectiveness. Before buying, check the ingredients, independent testing where available, the doses actually stated and the claims authorised. No brand has a monopoly on the effects described in studies.
Creatine ultimately illustrates two things at once: a supplement whose effects on intense exercise are supported well enough to be recognised by European regulations, and a line of research whose promises for the brain remain to be confirmed. The decision to take it therefore depends less on its popularity than on the activity undertaken, the state of one’s health and what one is really seeking to improve.
