Creatine and Your Menstrual Cycle: What the Research Shows
Most creatine research was built on a simple assumption: that men and women respond to supplementation the same way. That assumption is being tested properly for the first time. Sex hormones, particularly oestrogen and progesterone, directly influence how the body makes, transports and uses creatine, which means the menstrual cycle itself may change how creatine behaves.
Here is what the actual trials looking at creatine across the menstrual cycle have found, including the two questions we get asked most: does it hit differently depending on where you are in your cycle, and does it make period bloating worse.
In this article
How Hormones Change Creatine Metabolism
In 2016, a foundational review in the journal Amino Acids proposed a genuine shift in how researchers think about creatine and women: that oestrogen and progesterone influence the activity of creatine kinase, the enzyme creatine relies on to help regenerate energy in muscle cells, and affect how the body produces and transports creatine in the first place.
A 2025 review in the Journal of the International Society of Sports Nutrition, which pulled together the evidence on creatine across a woman’s reproductive lifespan, confirmed this remains an active area of research. The luteal phase (the second half of the cycle, after ovulation, when oestrogen and progesterone are both elevated) is associated with increased protein breakdown and reduced carbohydrate storage, which is part of the physiological rationale for why creatine’s effects might differ by cycle phase.
Creatine’s Effect During the Luteal Phase
A 2023 randomised, double-blind, cross-over trial tested this directly. Thirty-nine active women took either 20g of creatine monohydrate per day or a placebo, with performance and recovery measured in both the follicular (low hormone) and luteal (high hormone) phases of their cycle.
During the high-hormone luteal phase, fatigue index was reduced by 5.8% with creatine monohydrate, compared with just 0.1% for placebo, suggesting greater fatigue resistance when hormone levels are elevated.
Creatine did not meaningfully change heart rate variability in this trial. The consistent finding was specifically around fatigue resistance during repeated sprint efforts, and specifically during the phase of the cycle when hormone-driven performance dips tend to show up. It’s one trial, and a small one, but it’s a genuinely useful data point for anyone who notices their training feels harder in the second half of their cycle.
Does Creatine Make Period Bloating Worse?
This is one of the most common questions we get, understandably, since a lot of women already deal with fluid retention around their period without adding a supplement into the mix. A 2023 randomised, placebo-controlled trial published in Nutrients tested exactly this. Thirty women took either creatine monohydrate or a placebo, with body mass, total body water, extracellular fluid and intracellular fluid all measured across both the follicular and luteal phases using bioelectrical impedance.
The result: change in body mass was not significantly different between the creatine and placebo groups, in either phase of the cycle. Creatine did not measurably worsen fluid retention markers beyond what happens naturally across the cycle. If you already notice bloating around your period, that is a hormonal pattern that exists independently of creatine, the data doesn’t support creatine meaningfully adding to it.
Should You Time Creatine Around Your Cycle?
Based on the current evidence, no. None of the trials above found a reason to stop and start creatine around your cycle, or to load higher during any particular phase. The benefit observed in the luteal-phase trial came from consistent daily supplementation, not from timing doses to a specific week.
The research so far actually supports the opposite approach: take it every day, year-round, and let the body maintain a steady, saturated creatine store. Consistency is what the studies were built around, and it’s the only approach the current evidence actually supports.
How Much to Take
The trials above used higher loading-style doses (20g/day) over short periods to see measurable effects quickly in a research setting. For everyday use, the International Society of Sports Nutrition’s standard recommendation still applies: a maintenance dose of 3 to 5g of creatine monohydrate per day, taken consistently, with no loading phase required.
Look for a pure, micronised creatine monohydrate with no unnecessary fillers, so it dissolves easily and you know exactly what you are taking.
Safety and Limitations
Creatine monohydrate has one of the longest safety track records of any sports supplement. Both trials referenced above reported it was well tolerated, with no adverse effects linked to supplementation across either cycle phase.
That said, the research specific to menstrual cycle phases is still a small body of evidence, a handful of trials with modest sample sizes. If you have an existing health condition, are managing a hormonal disorder, or are unsure whether creatine is right for you, it’s worth checking with your doctor first.
The Bottom Line
The research on creatine and the menstrual cycle is still developing, but what exists points to two reassuring conclusions: creatine may help offset the fatigue that shows up during the high-hormone luteal phase, and it does not appear to meaningfully add to period-related bloating. Neither finding is the final word, both come from single trials, but both are useful, specific answers to the two questions women ask most about creatine and their cycle.
If you’d like to try it, our creatine for women is a pure, micronised creatine monohydrate with no fillers or added flavours, dosed in line with the research above.
This article is general information, not medical advice, and is not a substitute for guidance from your doctor, particularly if you are managing an existing health condition or taking medication.
Jasmine Meagher
BSc Food Science and Nutrition · Founder, Ritua
Jasmine founded Ritua to bring evidence-based, TGA-compliant supplements to Australian women. She writes about the research behind every ingredient Ritua sells.
FAQs
Does creatine affect performance differently depending on your cycle?
A 2023 trial found creatine reduced fatigue index by 5.8% (versus 0.1% for placebo) during the luteal phase, the second half of the cycle when hormone levels are higher and performance often dips. It’s one small trial, but the finding is specific and measurable.
Does creatine make period bloating worse?
A 2023 randomised trial measuring body mass and fluid markers across the cycle found no significant difference between creatine and placebo groups in either phase. The current evidence doesn’t support creatine adding meaningfully to period-related bloating.
Should I stop taking creatine during my period?
No, the research supports consistent daily use rather than cycling on and off around your period. None of the current trials found a benefit to timing or pausing supplementation around any cycle phase.
How much creatine should I take?
The general recommendation from the International Society of Sports Nutrition is 3 to 5g of creatine monohydrate per day, taken consistently, with no loading phase required.
Does hormonal contraception change how creatine works?
The 2023 fluid distribution trial included both naturally-menstruating women and women using hormonal contraception, and found consistent results across both groups. There isn’t yet enough dedicated research to say definitively whether contraceptive use changes creatine’s effects.
Sources
- The Effects of Creatine Monohydrate Loading on Exercise Recovery in Active Women throughout the Menstrual Cycle. National Institutes of Health (PMC), 2023.
- A Randomized Controlled Trial of Changes in Fluid Distribution across Menstrual Phases with Creatine Supplementation. Nutrients, 2023.
- Creatine in women’s health: bridging the gap from menstruation through pregnancy to menopause. Journal of the International Society of Sports Nutrition, 2025.
- Creatine for women: a review of the relationship between creatine and the reproductive cycle and female-specific benefits of creatine therapy. Amino Acids, 2016.
- International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. National Institutes of Health (PMC).