No, creatine does not cause infertility. There is no published evidence linking creatine supplementation to reduced fertility in men or women. In fact, early research points in the opposite direction: creatine appears to play a supportive role in reproductive cell energy and may modestly improve some fertility markers.
Where the Concern Comes From
Most fertility worries about creatine trace back to a single 2009 study on college-aged rugby players. After a seven-day loading phase of 25 grams per day, participants saw a 56% increase in dihydrotestosterone (DHT), a potent form of testosterone linked to hair loss and, in theory, hormonal disruption. DHT remained 40% above baseline after an additional 14 days at a lower maintenance dose. That study made headlines and sparked ongoing speculation about creatine’s hormonal effects.
The problem is that no other study has replicated those DHT results. Twelve additional studies have examined creatine’s effect on testosterone at doses ranging from 3 to 25 grams per day over periods of six days to 12 weeks. Ten found no change in testosterone levels. Two reported small increases that were not considered physiologically meaningful. Five of those studies also measured free testosterone, the form your body actually uses to produce DHT, and none found an increase. The original DHT finding remains isolated, involved only 16 participants, and has not been confirmed.
What Creatine Actually Does in Reproductive Cells
Creatine isn’t a foreign substance your body has to deal with. It’s a natural compound your cells use to recycle energy. The creatine-phosphocreatine system acts as a rapid energy buffer, shuttling high-energy phosphate molecules from where they’re produced to where they’re needed. This system is especially important in cells with high or fluctuating energy demands.
Both sperm and egg cells fall squarely into that category. In sperm, creatine kinase (the enzyme that manages creatine energy transfer) helps shuttle energy from the mitochondria in the midpiece to the tail, which powers movement. Research on human sperm cells shows that while creatine isn’t the only fuel source for motility, it supplements energy production under certain conditions, particularly when other fuel sources are limited. Demembranated sperm models can be reactivated using creatine phosphate and ADP, confirming that the creatine energy system is functional in these cells.
In women, reproductive organs are among the most energy-demanding tissues in the body. The ovaries express genes involved in creatine transport and synthesis. Human ovarian stromal cells, which surround and support the developing egg, show detectable levels of the enzymes needed for creatine production. Creatine and phosphocreatine have been measured directly in human oocytes at concentrations of roughly 4 to 5 millimoles per kilogram of dry mass. Expression of creatine kinase genes has even been found to be elevated in women who produce good-quality embryos during assisted reproduction.
Early Evidence in Men
A 2025 randomized controlled pilot trial looked at what happens to sperm quality when men supplement with creatine for eight weeks. Among participants who received creatine (with or without an additional antioxidant called ubiquinol), 60% showed an improvement in sperm concentration at the eight-week mark, compared to only 20% in the control group. That difference was statistically significant.
The results were particularly notable for men who started with low sperm counts. Every participant with low sperm concentration who received creatine showed improvement, while those in the control group stayed the same or got worse. The group receiving creatine plus ubiquinol saw an average rise of 7.4 million sperm per milliliter, though this specific increase didn’t reach statistical significance due to the small sample size. Sperm creatine levels themselves rose by about 36% in the combination group, confirming that supplemental creatine actually reaches these cells.
This is preliminary data from a small trial, not a definitive answer. But it directly contradicts the idea that creatine harms male fertility.
Effects on Menstrual Health and Female Fertility
A large observational study using U.S. national health survey data from 2017 to 2020 found that women who consumed at least 13 milligrams of dietary creatine per kilogram of body weight daily had a 25% lower risk of irregular menstrual periods compared to women with lower intake. Women with regular cycles consumed significantly more creatine on average (11.1 versus 9.8 milligrams per kilogram per day). Higher dietary creatine was also associated with reduced risk of obstetric conditions and pelvic pathology.
These findings make biological sense. Estrogen, which fluctuates throughout the menstrual cycle, is a major regulator of cellular energy metabolism. When estrogen drops during the follicular phase (the first half of the cycle), creatine kinase levels also appear to dip. Supplemental creatine could help bridge that energy gap. During the luteal phase (after ovulation), when protein turnover increases, creatine may support muscle preservation and reduce menstrual discomfort by helping maintain cell hydration.
Creatine also functions as an antioxidant, which could reduce oxidative stress in ovarian and oviductal tissue. In animal models, maternal creatine intake has improved egg production and quality. Researchers have suggested that creatine supplementation may be particularly relevant for women during menstruation, pregnancy, postpartum recovery, and menopause, all periods when hormone-driven shifts alter how the body produces and uses creatine.
Safety Profile at Standard Doses
The International Society of Sports Nutrition has stated that creatine monohydrate supplementation is safe for healthy individuals and that there is no scientific evidence of detrimental effects from short- or long-term use within recommended guidelines. Their position goes further, noting that creatine may actually be beneficial for injury prevention and management of certain medical conditions.
No long-term studies have identified adverse effects on reproductive organs. The typical supplementation protocol of 3 to 5 grams per day is well-studied across populations ranging from adolescents to older adults, with consistent safety data. The concerns about fertility are not supported by the body of evidence available, and the biological role creatine plays in reproductive cells suggests it is more likely to support fertility than impair it.