Creatine: One Supplement That Holds Up

Most supplements arrive with big claims and thin data. Creatine is different. It has decades of research behind it and the evidence has kept growing — especially for people who care about staying strong and capable as they age.

What it actually does well

Creatine increases the amount of phosphocreatine stored in muscle. This helps recycle energy quickly during short, intense efforts. When it is combined with progressive resistance training, the results are consistent across multiple meta-analyses in older adults:

•  Greater gains in lean tissue mass (typically around 1–1.4 kg more than training alone)

•  Improvements in strength, particularly upper body

•  Better performance on functional tasks such as sit-to-stand

The benefits are clearest when people train regularly. Creatine appears to amplify the adaptive response to strength work rather than replace it.

There is also published research — including meta-analyses — showing modest improvements in memory and some other cognitive measures, especially in older adults or when people are sleep-deprived or mentally fatigued.

A 2023 meta-analysis by Prokopidis and colleagues found clearer memory benefits in older adults (Prokopidis et al., Nutrition Reviews, 2023), and a 2024 review by Xu et al. reported positive effects on memory, attention time and processing speed (Xu et al., Frontiers in Nutrition, 2024). It is not dramatic and not as consistent as the muscle evidence, but it is not accurate to say there is no good research. Some people notice the difference most clearly during periods of poor sleep, which matches the conditions where the research tends to show the strongest signal.

The longevity angle

Sarcopenia — the gradual loss of muscle mass and strength with age — is one of the strongest predictors of reduced independence later in life.

Resistance training remains the foundation.

Creatine is one of the few supplements that reliably makes that training more effective for many people. That is why it sits higher than most of the optimisation noise.

Kidney function — the common concern

One frequent worry is kidney health, because creatine can raise the creatinine level that appears on blood tests. Creatinine is a normal breakdown product of creatine, so higher creatine stores naturally produce a bit more of it. When researchers measure actual kidney filtration using methods that are independent of creatinine, the evidence does not show damage in healthy people at standard doses (usually 3–5 g per day).

If you already have kidney disease or significant risk factors, check with your doctor first. And if you have blood tests while taking creatine, it is worth letting the clinician know so the creatinine result is interpreted correctly.

Practical points

•  Most research for muscle uses 3–5 g of creatine monohydrate per day. A loading phase is optional — consistent daily use is enough for most people.

•  Some cognitive studies, particularly those involving sleep deprivation, have used higher short-term doses (often 10–20 g). For everyday use, 3–5 g remains a practical and well-supported starting point.

•  In the first 1–2 weeks many people notice a small increase on the scales (often 0.5–2 kg). This is almost entirely water drawn into the muscle cells alongside the creatine — not fat. Muscles can feel slightly fuller. Performance changes are usually subtle at this stage.

•  By weeks 3–4, once muscle creatine stores are closer to saturation, many notice they can squeeze out an extra rep or two on harder sets, or recover a little better between efforts. Actual measurable strength and lean mass differences compared with training alone typically become clearer after 4–6 weeks of consistent training and supplementation.

•  Cognitive effects, when they occur, are often noticed more during periods of poor sleep or mental fatigue rather than as a constant “brain boost.”

•  Vegetarians and vegans often start with lower stores and may notice clearer effects.

•  Individual response varies. It is not magic.

Honest limits

• Without resistance training the benefits shrink.

• It will not replace sleep, protein intake, or consistent movement.

• It is a useful adjunct, not a foundation.

Bottom line

In a landscape full of recovery gadgets and optimisation trends with weak data, creatine is one of the supplements that has quietly built a solid evidence base. It supports muscle and to a lesser extent, brain function as we age — provided the basics are already in place.