The Journal

Nutrition

Creatine: fuel or fad?

Dr Amy Shacaluga·18 August 20264 min read

Creatine used to live in the gym bags of twenty-something men. It is now one of the fastest-growing health searches among women, especially women in perimenopause and beyond, and patients have started asking about it in clinic.

So is this another supplement fad, or is there something real here? The honest answer sits in between, and it is worth knowing exactly where the line is. As a consultant obstetrician and gynaecologist practising lifestyle medicine, I find creatine one of the more interesting cases: a supplement with decades of safety data and genuine evidence, being marketed with claims that sometimes run ahead of that evidence.

What creatine actually is

Creatine is not a steroid and not a stimulant. It is a compound your own body makes, and you eat small amounts in meat and fish. Its job is energy: it helps regenerate the rapid-fire fuel your muscles and brain use for short, demanding efforts. Body stores are typically not full, which is why supplementing can increase them, and there is some evidence women carry lower baseline stores than men.[1]

Plant foods do not fill that dietary gap. Creatinine is the non-enzymatic cyclisation product of creatine and phosphocreatine. Creatine is made only by vertebrates (AGAT/GAMT pathway, liver–kidney–pancreas) and stored almost entirely in skeletal muscle. Plants have no creatine synthesis pathway and no muscle, so plant foods contain essentially none of either. Analytical reports of “creatine in plants” are trace-level and nutritionally irrelevant. Fortified or fermented plant products can contain creatine if creatine monohydrate has been added (vegan supplements, some sports foods). That is an additive, not an intrinsic plant constituent. Yeast extracts and fermented soy do not contribute appreciably.

Why midlife women, specifically?

Because of muscle. From perimenopause onwards, women lose muscle at an accelerated rate while gaining fat, a shift documented in long-term studies of the menopause transition. Muscle is the engine of metabolism, insulin sensitivity and future independence, so anything that helps you keep and build it in midlife deserves attention. That is exactly where creatine’s best evidence sits.

What the evidence actually shows

The strong claim: in postmenopausal women, creatine combined with resistance training improves lean muscle mass and strength beyond what training alone achieves. This is supported by systematic reviews and meta-analyses of randomised trials.[1],[2] The key phrase is “combined with resistance training”. Creatine is an amplifier of the work, not a substitute for it. Taken on the sofa, it builds nothing.

The emerging claims: bone health, brain and mood. A two-year randomised trial in postmenopausal women found benefits for bone geometry alongside lean mass, though the bone evidence overall is mixed rather than settled.[1] For the brain, systematic-review evidence suggests creatine may support memory, and there are early signals for mood and even sleep, which is why you will see it marketed for “menopause brain fog”.[1] I would call this genuinely promising and genuinely unproven. The studies are small, and almost none of this research has been done in perimenopausal women specifically.[1] Anyone telling you creatine is proven to fix brain fog is ahead of the data.

If you decide to try it

The evidence-based version is unglamorous: 3 to 5 grams of creatine monohydrate daily, the cheapest and best-studied form, taken consistently, alongside a proper resistance-training programme.[1],[3] Loading phases are optional, not required.

Safety data over decades is reassuring in healthy adults. The common side effect is mild water retention or bloating in the first weeks. Two practical notes from the precision side of clinic: creatine can nudge up creatinine, the marker used to estimate kidney function, so mention that you take it before blood tests; and if you have kidney disease, talk to your doctor first.

The bigger principle

Creatine is a good example of how I think about every intervention: what does the evidence actually show, in whom, and does it fit your biology and your life? For one woman, creatine plus two strength sessions a week is an excellent, evidence-aligned investment in her metabolic future. For another, it is a distraction from the sleep, nutrition or training foundations that would move her health further. Working out which woman you are is precisely what a consultation is for.

References

1. Smith-Ryan AE, et al. Creatine in women’s health: bridging the gap from menstruation through pregnancy to menopause. J Int Soc Sports Nutr. 2025.
2. Creatine monohydrate for lean mass, strength, and bone density in postmenopausal women: a systematic review and meta-analysis. 2025. PMID: 42141930.
3. Smith-Ryan AE, et al. Creatine supplementation in women’s health: a lifespan perspective. Nutrients. 2021.