Creatine: the gym supplement with a growing case for the brain

Creatine is made in the body and stored in muscle, where it helps supply energy for short, hard efforts. As a supplement, creatine monohydrate powder has been a gym staple for thirty years. The newer interest is in the brain.

Muscle

A 2023 meta-analysis in Nutrients found creatine taken with resistance training produced a small extra increase in directly measured muscle size, in both the upper and lower body, compared with training alone. A separate 2023 meta-analysis found it made no difference to VO2 max, the measure of aerobic fitness.

Memory and thinking

• A 2023 meta-analysis in Nutrition Reviews found creatine improved memory compared with placebo. The effect was large in older adults aged 66 to 76 and close to zero in people aged 11 to 31. The dose, from 2.2 to 20 grams a day, and the length of use, from five days to 24 weeks, did not change the result.
• A 2024 meta-analysis in Frontiers in Nutrition rated the evidence for memory as moderate certainty. Evidence for processing speed, attention and overall cognition was low certainty.

Kidneys

Creatine raises blood creatinine, a marker doctors use to check the kidneys, which has fed worries about kidney harm. A 2025 meta-analysis in BMC Nephrology found no significant change in GFR, the actual measure of kidney filtration, and concluded kidney function was preserved.

Yes, but

Because creatine raises creatinine, it can make a routine kidney blood test look worse than it is; tell your doctor you take it. Most trials are in healthy people, and supplements vary in quality.

When to talk to your GP

If you have kidney disease, diabetes or high blood pressure, or take medicines that affect the kidneys.

Sources

1. The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis, Front Nutr, 2024
2. Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis, Nutr Rev, 2023
3. The effects of creatine supplementation combined with resistance training on regional measures of muscle hypertrophy, Nutrients, 2023
4. Effect of creatine supplementation on kidney function: a systematic review and meta-analysis, BMC Nephrol, 2025
5. Creatine supplementation and VO2max: a systematic review and meta-analysis, Crit Rev Food Sci Nutr, 2023

Checked 3 October 2026. Spotted something out of date? Tell us via the about page.

General information, not medical advice. Check with your GP first, especially if you are pregnant, have a heart condition or take medication.