The short answer
- For muscle and strength, with resistance training: works
- Pooled trials in postmenopausal women found small but real gains in lean mass and leg strength when creatine was paired with training.
- For bone density: not proven
- Bone density did not change overall in the pooled trials.
- For brain fog: not proven
- The trials in postmenopausal women measured muscle, strength and bone. They did not show a change in thinking or memory.
What it is
A compound your body already makes and that you also get from meat and fish. Muscles use it for short bursts of hard effort. The form used in almost every trial is creatine monohydrate.
What the studies say
- A 2025 review pooled seven randomized trials in 608 postmenopausal women, average age about 62.
- Creatine added about 0.37kg of lean mass compared with placebo.
- Leg press strength improved by about 7.5kg across three of the trials.
- The gains showed up when women took at least 5g a day alongside resistance training. Trials using 3g a day or less with no training showed no measurable effect.
- Bone density was unchanged. Side effects were mild and no different from placebo, and kidney blood tests did not change.
- Worth knowing about that review: the authors declared industry support, and one of them chairs a creatine advisory board funded by a manufacturer. It is still the best pooled evidence we have in this group of women.
How much people take in trials
The trials that found a benefit used at least 5g a day of creatine monohydrate with resistance training. Sports research has used a loading phase of 20g a day for up to 7 days, then 3g to 5g a day.
This is what the research used. It is not a dose for you.
What a label is allowed to say
UK law only lets a supplement say what is on the official list. For this one, that is:
- Daily creatine consumption can enhance the effect of resistance training on muscle strength in adults over the age of 55
- Creatine increases physical performance in successive bursts of short term, high intensity exercise
Both claims need 3g of creatine a day. The first also needs resistance training at least three times a week. Creatine on its own, with no training, is not what was approved.
In the US the rules are looser. A label may say how a nutrient supports the body if the company holds evidence for it. The FDA does not check the claim first, which is why US labels carry the line saying the FDA has not evaluated it.
Safety
- The common effect is a small weight gain from water held in the muscle.
- Some people report nausea, loose stools, cramps or stiffness. The reports are anecdotal rather than from trials.
- If you have kidney disease, creatine is not one to start on your own.
- Without resistance training there is little sign it does anything for muscle.
Ask your doctor first if
- You have kidney disease or a history of kidney problems.
- You are on medicines that affect your kidneys.
- You are not sure whether resistance training is safe for you yet.
This is general information, not medical advice. Check with your doctor or pharmacist, especially if you take medication.