Your Cycle, Your Creatine

Why Hormones Change Everything About How Your Body Uses Energy

If you've ever felt like your workouts are weirdly harder some weeks than others — like your body just didn't get the memo that today was supposed to be a good training day — you're not imagining things. Your menstrual cycle is actively changing how your body produces and uses energy. And creatine is right in the middle of it.

Most creatine research was done on men, who have relatively stable hormone levels day to day. Women? We're working with a 28-ish day hormonal symphony that affects everything from muscle performance to brain function to how much water our cells are holding. It's a lot of variables — and for decades, researchers just... ignored them.

That's finally changing. And what they're finding is genuinely useful.

The Hormone-Creatine Connection

Here's what's happening under the hood. Estrogen and progesterone — the two main hormones cycling through your body each month — directly influence creatine kinase, the enzyme that regulates creatine metabolism. In plain English: your hormones affect how well your body can use creatine for energy.

During the follicular phase (the first half of your cycle, when estrogen is rising), your body tends to perform better. Energy is higher, recovery is faster, workouts feel more manageable. This is when your creatine system is humming.

During the luteal phase (the second half, after ovulation, when progesterone dominates), things shift. Research shows reduced sprint performance and slower phosphocreatine resynthesis — meaning your muscles can't recover between bursts of effort as quickly. This is also when PMS symptoms, bloating, fatigue, and brain fog tend to peak.

The Science: A 2023 randomized controlled trial (Moore et al., Nutrients) looked at how creatine supplementation changed fluid distribution across the menstrual phases, and a 2025 review in the Journal of the International Society of Sports Nutrition (Smith-Ryan et al.) summarizes what we know so far about creatine across the cycle.

Translation: researchers think the times your body feels the most depleted may be exactly when creatine stores matter most. It is still an early area of research.

What Creatine Actually Does for Your Cycle

Let's get practical. Here's what researchers are looking at:

Energy during the luteal phase: When phosphocreatine resynthesis slows down, having more creatine on board may act as a buffer. Think of it as extra fuel reserves so that the slowdown in refueling doesn't leave you stranded mid-workout.

Reducing menstrual discomfort: Creatine draws water into your cells, and the luteal phase is when many women feel bloated from fluid shifting outside the cells. The 2023 trial above looked at exactly this fluid shift. Whether that translates into less discomfort has not been proven yet, but it is one of the questions researchers are now asking.

Mood and mental clarity: Your brain uses creatine for energy too. Researchers are studying whether creatine affects mood and mental clarity across hormonal changes, but the human evidence is still early, and the 2025 review calls for more female-focused studies.

Cycle regularity: This one is surprising. A study of 4,522 U.S. women using national health survey data (Ostojic et al., 2024, NHANES 2017–2020) found that women who got at least 13 mg of creatine per kg of body weight from food each day had about 25% lower odds of irregular periods than women who got less. This was diet only, not supplements, and it shows an association, not cause and effect.

And What About Reproductive Health More Broadly?

The same NHANES analysis also looked at other reproductive health questions in the survey, such as hysterectomy and having the ovaries removed, and found these were reported more often by women with lower creatine intake from food. The authors are clear that a survey like this cannot show that creatine caused any of these differences, and that longer-term studies are needed.

The Science: Researchers theorize that creatine supports the energy demands of reproductive tissues, since the uterus and ovaries use a lot of cellular energy. This is a working theory, not a proven effect.

This is emerging science, and the researchers behind the 2025 review issued an explicit call for more studies in women. What we can say today is that creatine monohydrate has a long safety record, and most women in the NHANES data were not getting the recommended amount from food.

What This Looks Like in Practice

Research commonly uses 3–5 grams of creatine monohydrate a day, and consistency matters far more than timing. You don't need to sync it to your cycle. GUMvees Creatine follows its Health Canada licensed directions (NPN 80126442): adults 18+ take 3–5 gummies (3–5 g) a day for the first 4 weeks, then 2–5 gummies (2–5 g) a day, and drink plenty of fluid before, during and after exercise. Each gummy contains 1 g of creatine monohydrate.

Some researchers suggest that women who notice tougher luteal phases may be a group worth studying for year-round creatine use, rather than cycling on and off. If you have a medical condition or are pregnant or breastfeeding, talk to your health care practitioner before starting creatine.

Creatine monohydrate. Every day. Simple as that.

Next, we move to one of the most underserved chapters in women's health: perimenopause and menopause. This is where the creatine conversation gets urgent — and where the newest research is genuinely exciting.

Next up: Article 3 — The Menopause Chapter: Your Brain, Your Bones, and the Supplement You Should Have Started Yesterday

Sources

• 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;22(1):2502094.
• Moore SR, et al. A randomized controlled trial of changes in fluid distribution across menstrual phases with creatine supplementation. Nutrients. 2023;15(2):429.
• Ostojic SM, et al. Association between dietary intake of creatine and female reproductive health: Evidence from NHANES 2017–2020. Food Sci Nutr. 2024;12(7):4893–4898.