At the 2025 Creatine Conference, a panel of researchers who study creatine in women sat down to answer a blunt question from moderator Dr. Richard Kreider: what will it take to get accurate creatine information to women? The panel included Dr. Susan Kleiner, a sports dietitian who has spent decades translating nutrition science into products; Dr. Stacey Ellery, a perinatal physiologist who leads the only human creatine in pregnancy program in the world; Dr. Ann Brown, who studies creatine, sleep and mood in women; Dr. Abbie Smith Ryan, whose lab runs creatine trials across the menstrual cycle and menopause; and Peggy Reichelt, founder of a German menopause nutrition company. What follows is a restructured account of what they said, checked against the published research wherever a claim could be checked.
Why women were left out of creatine research
Kreider opened by reminding the room how recently women’s nutrition meant taking a men’s product, coloring it pink and making it smaller. Creatine is a clear example. It is one of the most studied supplements in existence, yet the studies overwhelmingly enrolled men. Kreider estimated that of roughly 700 clinical trials, about a third have included any women at all. The picture is worse when you look for trials that studied women on their own. A 2020 systematic review led by Deborah de Guingand and Stacey Ellery counted 656 creatine intervention studies and found only 58 that enrolled women exclusively, about nine percent.
Why does that matter? Because women are not smaller men when it comes to creatine. The 2021 lifespan review by Smith Ryan and colleagues in Nutrients reports that women carry roughly 70 to 80 percent less stored creatine than men, and that estrogen and progesterone influence creatine synthesis, transport and the enzyme that recycles it. The panel’s own 2025 review in the Journal of the International Society of Sports Nutrition, written by Smith Ryan, Brown, Kleiner, Ellery and colleagues, states plainly that no study has yet examined creatine in perimenopausal women and that the pregnancy literature is mostly from animals.
Brown put it simply: the field needs more of what it is already doing. Only a handful of labs run female creatine research, and she credited friendships and collaborations, rather than funding calls, for pulling her into the work. Each lab can only ask a few questions, and the list of unanswered ones is long. She asked industry as well as government to fund it.
What women actually ask about creatine
Reichelt provided the consumer view. When she attended her first ingredients trade fair in 2019 and asked what was on offer for women’s health, the answer was urinary tract infections. Nothing else. By 2024 the same fair had a track on female life stages. Her company began in the menopause space in Germany at a time when, in her words, there was nothing, and a survey her company ran with around 2,000 women found that 88 percent had never heard the word perimenopause even though many reported classic symptoms. That figure is company data and has not been published, so treat it as an illustration rather than a statistic.
When she launched a creatine product, the first questions were predictable: will I get bulky, will I retain water, is it dangerous, what does it do to my kidneys. Six months on, she said, the questions had become more specific and the feedback centered on energy and feeling better. That is self reported and uncontrolled, but it matches what the science suggests women notice first.
The evidence on the bulking and water questions is reassuring. The de Guingand meta analysis pooled 29 studies with 951 female participants and found no deaths, no serious adverse events, and no significant difference between creatine and placebo in total side effects, digestive complaints or weight gain. Kreider added that his group’s own data, to be presented later at the conference, find no support for the bloating women fear.
Reichelt also described a regulatory bind. In the European Union the only authorized creatine claims relate to physical performance during repeated bursts of high intensity exercise at 3 grams per day, and muscle strength with resistance training in adults over 55, both assessed by the European Food Safety Authority. Anything about brain, mood or bone risks fines. She said what would help her most is an authorized claim for cognition or mental health, because the evidence she saw at the conference in that area looked more solid to her than the bone evidence. The research reviewed below suggests she is roughly right about the relative strength, though both bodies of evidence are still small.
What women want from creatine versus what it does
Reichelt made a marketing observation the scientists did not dispute. Women approaching menopause are mostly worried about weight, appearance and energy. Telling them their muscles will get stronger can backfire, because “muscle” reads as “bulk.” Her workaround is to talk about being able to get up from a chair or a toilet unaided in later life, then let the bone and muscle benefits come along with the outcomes women can feel: sleep, energy and mental clarity.
Kleiner, who has advised supplement companies for years, said the sales data agree. Companies that invest in education do better with women, and Kreider added that it builds loyalty because women feel they are getting honest information and making an informed choice. Smith Ryan pushed the point further: the industry is now flooding the market with products “for women” without the education to go with them, which makes things more confusing, not less. Women, she said, thrive on understanding what a product is supposed to do in their bodies, and there is data behind that.
Kleiner raised a related problem. Industry tends to promote the lowest dose found effective in any single study, because that saves money on the most expensive ingredient. Creatine is cheap, so the motive is different, but the result is the same: women eat one or two gummies, get one or two grams, see nothing, and conclude creatine does not work. Her plea to researchers was to test multiple doses and to say clearly what dose produces what benefit for a woman of a given age and size.
Creatine and the menopause transition
Smith Ryan, who described herself as biased toward this life stage, said perimenopause is where women are most desperate for help and where the evidence is thinnest. Aside from unpublished results she had heard the day before, she said there are no creatine trials in perimenopausal women. The 2025 review confirms that gap. Sleep problems, fatigue, brain fog, joint pain, bone loss and muscle loss all cluster in this window, and creatine is not going to solve all of it. She wanted the field to take a strictly evidence led approach rather than promising the transition away.
After menopause the picture is better, though not uniformly positive. The lifespan review reports that postmenopausal women gain muscle size and function with higher creatine doses (around 0.3 grams per kilogram per day) and see favorable bone effects when creatine is combined with resistance training. But the two largest trials tell a mixed story. A two year randomized trial in Brazil gave 200 postmenopausal women with osteopenia 3 grams per day or placebo without a training program and found no benefit for bone density, lean mass, strength or falls. A separate two year Canadian trial gave 237 postmenopausal women a weight based dose alongside supervised resistance training and walking, and found no difference in bone density at the hip or spine, but some improvement in the geometry of the upper femur, which relates to how the bone resists bending.
The honest summary is that creatine alone does not appear to protect bone, that creatine plus serious training may modestly improve bone structure, and that the muscle benefits require doses higher than the 1 to 2 grams in a couple of gummies. Reichelt said her own reason for starting creatine was osteopenia, but she was quick to add that most of her customers are not that “nerdy” and want to feel a difference in energy and body composition.
Creatine, mood and the brain
Several panelists said the mental health and cognition data are the most persuasive part of the female creatine literature, and this is where the evidence is at its most interesting. The landmark trial, published in the American Journal of Psychiatry in 2012, randomized 52 women with major depressive disorder to the antidepressant escitalopram plus 5 grams of creatine daily or plus placebo for eight weeks. The creatine group improved more, and the difference appeared by week two. At eight weeks, remission was about twice as common in the creatine group. Adverse events were no more frequent with creatine, though serum creatinine rose, which is expected and reflects creatine turnover rather than kidney harm.
That is one trial of 52 people, run as an add on to medication, not a replacement for it. Later small studies in adolescent girls with treatment resistant depression suggested that higher doses raise brain phosphocreatine more, and that the rise tracks symptom improvement. A pooled analysis of creatine and depressive symptoms found benefit but also substantial variation between trials and signs of publication bias. Anyone reading this with depression should discuss it with their clinician; creatine is not a treatment on its own.
On sleep and cognition, two studies are worth knowing. In 2011, Christian Cook’s team found that a single creatine dose taken 90 minutes before testing prevented the fall in passing accuracy that elite rugby players showed after a night of three to five hours’ sleep. In 2024, Ali Gordji Nejad’s group at Forschungszentrum Jülich gave 15 volunteers a single very large dose, about 0.35 grams per kilogram (roughly 25 grams for a 70 kilogram person), during 21 hours without sleep, and measured improved processing speed and memory along with changes in brain high energy phosphates on spectroscopy. The dose was far above normal daily use, the sample was tiny, and the authors themselves advised against replicating it at home. What the study does show is that the brain can take up creatine faster than previously assumed when energy demand is high.
Brown said her protocols now measure sleep quality alongside mood, because the two are deeply entangled, and Kreider suggested there may be room for combining creatine with sleep aids in what sports nutrition calls pre sleep nutrition. That remains an idea, not a finding.
Creatine in pregnancy and labor
Ellery works in what she called an incredibly challenging space. Most creatine tubs carry a pictogram of a pregnant woman with a line through it, and she said that image ends conversations before they begin. She understands why it is there. Pregnancy involves two patients, and the history of drugs introduced into pregnancy without adequate evidence is grim. Her position is that creatine in pregnancy must be consumer driven and safety first. Pregnant women, she noted, care about their baby far more than themselves, so safety data matter more than efficacy data, and the field has to level with them about what is and is not known.
Where does the evidence stand? A 2025 narrative review in Frontiers in Nutrition grades human evidence for creatine in pregnancy as limited, while animal studies show consistent protective effects against complications linked to oxygen shortage. Ellery’s group has now published the first human pharmacokinetic trial: a single 5 gram dose in third trimester women produced blood creatine levels comparable to non pregnant women, and modeling suggested that 5 grams taken three to four times daily would reach a target steady state within about three days. That is a dosing study, not an outcome study, and it involved fewer than ten pregnant women at each stage. Nobody yet knows whether creatine improves any pregnancy outcome in humans.
Smith Ryan offered a personal risk to benefit view. She called pregnancy the most athletic event a woman will ever do, said she took creatine during both of hers, and argued that when a pregnant woman has no appetite or room for the six chicken breasts it would take to match a scoop, 5 grams of creatine is a reasonable thing to consider, with little apparent risk. She was explicit that she is not a pregnancy researcher and that more work is absolutely needed. Readers should treat that as one scientist’s judgment for herself, not a recommendation, and talk to their own care provider.
Kreider asked whether creatine loading could help natural labor, since labor is muscle contraction and relaxation and creatine helps both. Ellery described a preliminary in vitro study with uterine biologists at Vanderbilt: strips of human myometrium obtained at cesarean delivery were bathed in medium containing 5 millimolar creatine for about 18 hours, the maximum the tissue could be kept viable, and contractile force was measured. The initial data, presented only as a poster, were not promising. But she listed the caveats herself: the dose was an educated guess, the exposure was short, and creatine uptake into the tissue has not yet been measured, although a labeled tracer was included so it can be. A trial comparing contraction patterns in laboring women given creatine or placebo is possible in principle but a long way off.
Ellery also mentioned unpublished findings that creatine concentrations in umbilical cord blood differ depending on whether the baby arrived by elective cesarean without labor, by unassisted vaginal birth, or by emergency intervention after labor went poorly. Something is happening to creatine metabolism during labor, she said, but nobody knows what. Her broader frustration is that a marathon runner’s fueling is timed to the minute based on decades of physiology, while the metabolic demands of labor have essentially never been characterized. She has obtained serial blood samples from laboring women collected for another study and plans a full metabolomic screen. Her stated goal is for labor to be, if not easy, at least a positive experience for more women.
One technical note she raised deserves passing on because it affects how readers should interpret tissue studies. Her group reports total creatine, meaning creatine plus phosphocreatine, because phosphocreatine breaks down within moments of tissue leaving the body unless the sample is snap frozen. Ratios of creatine to phosphocreatine from placental or uterine tissue are therefore prone to sampling error, and she declines to draw conclusions from them.
Creatine and fertility
Asked about fertility, Ellery called it a fascinating question that nobody has properly pulled together. Sperm express a creatine transporter of their own, distinct from the one used elsewhere in the body, and creatine concentrations in follicular fluid and fallopian tube fluid rise around ovulation. She suspects the creatine is there to power the burst of hyperactivated swimming sperm need to reach the egg.
The mouse research supports her. A 2018 study in Human Reproduction found that creatine in follicular fluid increased after ovarian stimulation and in oviductal fluid around ovulation, confirmed the transporter in sperm, and showed that adding creatine to IVF medium raised sperm ATP, prolonged motility, and reduced the number of sperm needed to fertilize eggs, with normal offspring born. A 2022 mini review by Sergej Ostojic notes that men with poor sperm count and motility tend to have low semen creatine, that a few pilot trials of oral creatine looked favorable, and that proper trials in a real world fertility context are missing. Kreider recalled that a section of a broader creatine and health paper cited a study of improved sperm count in men with low counts; that reference could not be verified for this article and should be treated as his recollection.
Ellery was careful about the human application. Couples in fertility treatment are, in her words, a highly vulnerable population, already offered a long list of unproven add ons. Even if the risk to benefit ratio might justify trying, she would not want creatine introduced as another add on without good data behind it. Her conclusion was that the research should absolutely be done, and done well.
Should teenage girls take creatine?
Kreider put the panel on the spot: would you recommend that female teenagers take creatine daily? Kleiner, speaking as a dietitian, answered food first. When her practice works with youth athletes, it evaluates their diet and tries to improve it across the board; more animal protein in a teenage girl’s diet brings iron and other benefits along with creatine. For a young athlete, she said, Smith Ryan’s work on strength and performance justifies supplementation. For adolescent girls in general, she admitted she would probably give creatine to her own daughters if they were still young, but she could not yet call that an evidence based recommendation.
The published guidance is consistent with her hedge. A 2018 review in Frontiers in Nutrition by Andrew Jagim and colleagues found strong support for creatine’s safety in active adolescents and minimal risk of adverse events, and the International Society of Sports Nutrition’s position stand says supplementation in children and adolescent athletes is acceptable with supervision, but only for young people in serious supervised training, eating a balanced diet, who understand proper use and do not exceed recommended doses. The same document notes that “not for under 18” label warnings are probably unnecessary and reflect legal caution rather than science.
Smith Ryan reframed the teenager question as the same risk to benefit calculation she applied to pregnancy. Whole foods first, but most women under consume both calories and protein, so 5 grams of creatine is potentially useful and the risk is very low. She has sons rather than daughters, and said she gives them a little creatine after an illness or when they are too active to eat enough. Brown described creatine as a safety net in the same spirit as a multivitamin: not a substitute for food, but a backstop for the days you cannot get it from food. She also shared that her six year old daughter, who suffered a brain injury before birth, takes creatine gummies.
Kreider’s own view leaned toward yes, and he backed it with population data. Analyses of the National Health and Nutrition Examination Survey by Ostojic and colleagues have found that Americans eating less than about 1 gram of creatine a day from food have higher odds of several conditions than those at or above that level, and a 2025 analysis linked to death records found lower all cause mortality among people meeting 1 gram a day. Kreider said 2 grams looked better still. Those are associations from dietary recall surveys and cannot show that creatine causes better health, but they do suggest that 1 gram a day is a reasonable floor, and that many women, whose average intake sits below it, do not reach that floor from food. His practical point was cost: 1 gram of creatine from salmon costs many dollars, while a scoop of creatine costs about fifteen cents.
How much creatine women need
Kreider recalled a 2010 era recommendation of 3 grams a day for everybody and said the evidence has only improved since. The closest verifiable source is the European Food Safety Authority’s 2011 opinion, which accepted 3 grams a day as the dose for the performance claim; that was a claim about exercise in adults rather than a general health recommendation, so the “for everybody” framing is his interpretation.
The mechanics of dosing matter more than most consumers realize, and the panel spent time on them. In Erik Hultman’s classic 1996 study, taking 20 grams a day for six days raised muscle creatine about 20 percent. Taking 3 grams a day produced a similar 20 percent increase, but it took 28 days to get there. Kreider quoted the low dose approach as reaching only about 70 percent of loaded stores in a month; the original data show the two protocols ending in roughly the same place at four weeks, so his number overstates the gap, but his methodological point is sound. If a trial uses a low dose without loading, the first month is spent filling stores, and an intervention that starts on day one may miss the effect.
Smith Ryan agreed. Her lab’s current design is a one week loading phase followed by a daily maintenance dose during a six week training study, so that a six week intervention does not stretch to twelve. She liked Kreider’s suggestion of formal guidelines for creatine research in women, including how to account for the menstrual cycle, which she said is still treated as black and white when it is not. Kreider asked the authors of the session summary paper to include a box of design recommendations, along the lines of an earlier framework for high quality sports nutrition trials.
Two consumer takeaways follow. First, the standard adult protocol, endorsed by the ISSN, is either a loading week at roughly 0.3 grams per kilogram per day then 3 to 5 grams daily, or simply 3 to 5 grams daily for at least a month before judging results. Second, the viral recommendation Reichelt saw online, 3 to 4 grams per kilogram of body weight, is off by about a factor of ten and would mean well over 200 grams a day. She said the trainer clearly had her decimal points wrong. Reichelt’s response to that kind of misinformation is to host live interviews with researchers, which she said also gives her a feedback loop for product development and for learning the language an 18 year old uses versus a 55 year old.
Sleep, cortisol and PMS
An audience question asked whether creatine could influence cortisol, given its links to sleep. Brown answered honestly that she did not know and had not studied it. She noted that the cortisol awakening response is typically elevated in people with diagnosed anxiety, which would make it an interesting marker in populations with anxiety or depression, but she had no data. Kreider said his group sees a tendency toward lower cortisol and less muscle damage when creatine is given acutely around recovery. No published trial supporting that could be located for this article, and Cook’s 2011 sleep deprivation study, which measured salivary cortisol, does not report a creatine effect on it. Readers should treat the cortisol idea as untested. Kleiner added a note of caution for anyone on social media: the “cortisol face” and anti cortisol diet trends have no data behind them, even though anxiety is a real and growing concern among younger consumers.
The final question concerned premenstrual syndrome. Kreider recalled survey feedback from the 1990s in which women reported less severe PMS symptoms and cramping on creatine. His group tried to run a proper study, but the screening required to confirm PMS was so demanding that recruitment failed. Smith Ryan said the area is ripe, though she doubted creatine alone would be the answer, and observed that PMS is far less taboo now than it was, which should make recruitment easier. Kreider offered to share the old protocol. Brown added that anyone studying PMS should measure sleep at the same time, citing Fiona Baker’s work on how the menstrual cycle and sleep disrupt each other, and said she will add PMS measures to her own sleep protocols going forward. There are no published creatine trials in PMS to report.
Misinformation and the kidney myth
Ellery said she still fields the same fears every day, and cannot understand why a person searching creatine for the first time is served a 1998 paper from The Lancet before any of the newer evidence. That paper was a single case report: a 25 year old man with an existing kidney disease, focal segmental glomerulosclerosis, who was taking the immunosuppressant cyclosporine, itself known to harm kidneys, and whose filtration rate fell while he used creatine and recovered after he stopped. A French sports newspaper reported it three days later as proof that creatine is dangerous for everyone, and the story spread worldwide.
The evidence since points the other way for healthy people. The ISSN position stand finds no compelling evidence of harm from creatine at up to 30 grams a day for five years in healthy individuals. NHANES analyses show no association between higher dietary creatine intake and kidney dysfunction. And a 2023 narrative review titled, pointedly, Is It Time for a Requiem for Creatine Supplementation Induced Kidney Failure, concludes that the case reports involved people with pre existing kidney disease or other confounders, and that the serum creatinine marker used to flag kidney trouble rises harmlessly in anyone taking creatine. People with existing kidney disease remain a group for whom medical supervision is essential.
Ellery’s prescription for the whole field was to be honest scientists in public: give people the data, do not sugarcoat it, and do not assume they cannot understand it. She will not tell a pregnant woman that creatine guarantees a complication free birth, because that is not true. She can show what the potential benefit is and how large it appears, and take people along for the ride. That, she said, is how you become the voice people want to hear instead of the one shouting loudest. Kreider closed with the same thought from the other direction: scientists may dislike social media, but altmetrics show a viral post reaches more people than any journal article ever will, and doctoral programs should probably start teaching it.