You've probably encountered creatine in the context of gym bros chasing bigger biceps. You've also almost certainly experienced the mid-afternoon brain fog that makes you question whether you've retained a single coherent thought since Tuesday. Here's what the research now tells us: these two things are connected in ways that matter specifically for women.
Creatine is a naturally occurring compound made from three amino acids, arginine, glycine, and methionine, stored primarily in muscle tissue, but also, crucially, in the brain. Your body uses it to regenerate ATP, the energy currency your cells run on. When your brain is working hard, it burns through ATP fast. Creatine phosphate helps replenish it.
The brain health research
A landmark 2003 study published in Proceedings of the Royal Society B found that just 5g of creatine per day for six weeks significantly improved working memory and intelligence test scores in young adults, particularly in tasks requiring speed of processing. (Rae et al., 2003)
A 2018 systematic review of randomised controlled trials found that creatine supplementation improved memory performance in healthy individuals, with the strongest effects seen in older adults and those under cognitive stress, including sleep deprivation. (Avgerinos et al., Experimental Gerontology, 2018)
Why women specifically
Women naturally synthesise less creatine than men. Research suggests women have approximately 70–80% of male baseline creatine stores, partly because creatine synthesis is influenced by testosterone, and partly due to average dietary patterns (women typically consume less creatine-rich meat and fish). (Smith-Ryan et al., Nutrients, 2021)
This matters because lower baseline stores mean more room to benefit from supplementation. There is also emerging, and still developing, research on creatine's relationship with serotonin regulation and mood, which is relevant given that cognitive fog and low mood during the luteal phase are common complaints linked to progesterone's influence on the central nervous system. This area needs more research specific to women before firm conclusions can be drawn, but the early signal is interesting.
What happens when you're sleep-deprived
Dr. Rhonda Patrick has discussed this with Dr. Darren Candow, one of the world's leading creatine researchers.
A German study found that a single dose of approximately 25–30g of creatine, taken during 21 hours of sleep deprivation, not only reversed the cognitive deficits of sleep deprivation, but actually enhanced brain function beyond well-rested levels. Worth filing away for Friday morning after Thursday night got the better of you.
BEFORE CREATINE
AFTER CREATINE
Dr. Patrick has also shared her own experience of taking around 20g when jet-lagged or under-slept before demanding work, including before giving a talk at 5am after minimal sleep. She reports a meaningful difference in mental performance. In short: when your brain is under stress, it burns through creatine faster than a standard 5g can replenish. Higher acute doses appear to saturate brain stores more rapidly.
The dose
Daily: 5g per day. No loading phase required. Timing matters less than consistency, with food, without food, morning or evening. Creatine monohydrate is the most researched form.
Acutely (under-slept, jet-lagged, cognitively stretched): Some people, including Dr. Patrick, increase to 15–25g on a single demanding day. Creatine's safety profile is well-established, though good hydration is important at higher doses.
Note: plant-based eaters tend to have lower baseline brain creatine stores, so the cognitive uplift from supplementation is typically more pronounced in this group.
The bottom line
Creatine is one of the safest and most-studied supplements available. For women, who start with lower baseline stores and may experience phase-specific cognitive fatigue, a consistent 5g daily habit is a genuinely useful tool. And on the days you've had three hours of sleep and a 9am presentation? Consider bumping it.