What it means
Creatine is a nitrogen-containing compound made from arginine, glycine and methionine, stored mostly in muscle as phosphocreatine, where it regenerates ATP during the first seconds of hard effort. The body makes about 1 g a day and meat and fish provide another 1–2 g; vegetarians have lower stores.
Supplementing 3–5 g of creatine monohydrate a day saturates muscle stores within three to four weeks, which is what every trial result rests on.
Why it matters for longevity
Muscle strength and mass are two of the strongest predictors of healthspan, and sarcopenia is the failure mode most older adults meet. Creatine is the one supplement that reliably augments the strength and lean-mass response to resistance training, in older adults as well as young ones.
What the evidence says
Meta-analyses of resistance-trained older adults (Chilibeck 2017, 22 trials) show creatine plus training added about 1.4 kg of lean mass and improved upper- and lower-body strength beyond training alone. Trials in postmenopausal women show modest preservation of bone density with training. In young adults the strength and power effect is one of the most replicated findings in sports science.
Cognition: a 2023 meta-analysis found small improvements in memory, especially in older adults and under sleep deprivation; a 2024 trial reported creatine partly offset the cognitive effects of a sleepless night. Safety: decades of trials at 3–5 g/day show no kidney harm in people with normal kidney function; creatinine rises slightly because creatine is its precursor, which is why kidney function is better read as cystatin C.
How to measure or use it
- 3–5 g of creatine monohydrate daily, any time, with or without food; loading phases are unnecessary.
- Expect 1–2 kg of water weight in the first weeks; it is intramuscular, not subcutaneous.
- Judge it on strength and a DEXA lean-mass trend over 12 weeks of training; read kidney function as cystatin C, since creatinine will read higher.
Related
- Muscle mass and ageing — why muscle is the target
- Supplements that have evidence — creatine at the top of the list
- The lean-mass protocol — creatine inside a plan
Frequently asked questions
Is creatine safe for the kidneys?
In people with normal kidney function, yes, across decades of trials. It raises creatinine slightly because creatine breaks down into it, so cystatin C is the better kidney marker.
Do I need to load?
No. 3–5 g a day saturates muscle in three to four weeks; loading (20 g/day for a week) gets there faster with more stomach upset.
Does creatine help cognition?
Modestly, in older adults and under sleep deprivation, per a 2023 meta-analysis. It is not a nootropic for well-rested young adults.
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