Creatine and Hair Loss: What the Actual Research Says

If you have spent any time in gym forums or supplement subreddits, you have probably seen someone claim that creatine causes hair loss. The claim is old, it is repeated constantly, and almost nobody citing it has actually read the study it comes from. That study is a single 2009 paper on 20 college rugby players, and it never measured hair loss at all. This article walks through exactly what that study measured, what the biology of DHT and hair loss actually says, what the research published since 2009 has found, and how to think about your own risk if you are considering creatine as part of a training plan built around something like the Scinergy macro calculator.

The 2009 study: 20 rugby players, serum hormones, 3 weeks

The paper is van der Merwe, Brooks, and Myburgh, "Three Weeks of Creatine Monohydrate Supplementation Affects Dihydrotestosterone to Testosterone Ratio in College-Aged Rugby Players," published in the Clinical Journal of Sport Medicine in 2009 (PubMed, 2009). It was a double-blind, placebo-controlled crossover trial run at a rugby institute in South Africa, and the total sample was 20 college-aged male rugby players, with 16 completing the full protocol.

The protocol used a standard creatine loading structure: 25 g per day of creatine monohydrate combined with 25 g per day of glucose for 7 days, followed by a 14-day maintenance phase of 5 g per day of creatine with 25 g per day of glucose. The placebo group received matched glucose doses with no creatine, 50 g per day during the loading week and 30 g per day during maintenance. Serum testosterone and DHT were drawn at baseline, after the 7-day loading phase, and after the 21-day mark, and researchers also tracked body composition at each checkpoint.

The result that gets quoted everywhere: total serum testosterone did not change in either group at any point. DHT, however, rose 56 percent above baseline after the 7-day loading phase and remained about 40 percent above baseline after the 14-day maintenance phase, both statistically significant changes (P less than 0.001). The ratio of DHT to testosterone rose 36 percent after loading and stayed 22 percent elevated through maintenance (P less than 0.01). The authors' own conclusion was measured, not alarmist: creatine supplementation "may, in part, act through an increased rate of conversion" of testosterone to DHT, and they called for further investigation given how widely creatine is used and how little was known about long-term effects on circulating androgens at the time.

Two details in the original data are routinely left out of the social-media version of this study. First, the creatine group started the trial with DHT levels roughly 23 percent lower than the placebo group, a baseline imbalance that inflates the apparent size of the later increase (Antonio et al. 2021, JISSN). Second, and most important, the study never looked at hair. No scalp photography, no follicle counts, no hair density measurement, no self-reported shedding. It measured a hormone in blood serum, full stop. The claim that this study "proves" creatine causes hair loss is an extrapolation the authors themselves did not make.

What DHT actually does to hair, and what it does not

To understand why a DHT increase is a plausible but incomplete worry, it helps to know the actual mechanism of androgenetic alopecia, or male and female pattern hair loss. The enzyme 5-alpha-reductase converts testosterone into DHT, a more potent androgen that binds strongly to androgen receptors in the dermal papilla of scalp hair follicles. In genetically susceptible follicles, that binding triggers a signaling cascade, including upregulation of TGF-beta1 and suppression of the Wnt/beta-catenin pathway, that progressively shortens the growth (anagen) phase of the hair cycle and shrinks, or miniaturizes, the follicle over repeated cycles (International Journal of Molecular Sciences, 2025).

The detail that matters most here is that this process depends heavily on genetic sensitivity, not just on how much circulating DHT a person has. Follicle androgen receptor density and the number of CAG repeats on the androgen receptor gene both influence how strongly a given follicle responds to DHT, and research summarized by hair restoration clinicians notes that normal, even low, levels of DHT are sufficient to drive miniaturization in a follicle that carries the susceptible receptor profile, while a follicle without that susceptibility can be exposed to higher-than-normal DHT and show no effect at all. In other words, DHT is closer to a necessary trigger than a dose-dependent poison: the pathway either exists in a given follicle or it largely does not, and pushing DHT modestly higher does not reliably turn a resistant follicle into a susceptible one.

This is exactly the logic pharmacologically confirmed by finasteride and dutasteride, the two drugs actually approved to treat pattern hair loss. Finasteride, a selective type II 5-alpha-reductase inhibitor, lowers circulating DHT by roughly 60 to 70 percent, while dutasteride blocks both major isoforms of the enzyme and lowers DHT by around 90 percent (Expert Opinion on Pharmacotherapy, 2023). Those are dramatic, sustained reductions achieved with a daily pill designed specifically to hit that one enzyme. A transient 40 to 56 percent rise in serum DHT from three weeks of creatine loading, in a hormone system that returns toward baseline once supplementation normalizes, is a different order of magnitude and a different kind of exposure than what actually treats or reverses pattern hair loss in the clinic.

What research since 2009 has found

No one has replicated the DHT finding

The single most important update in this story is that nobody has reproduced the original result. The 2021 International Society of Sports Nutrition review states plainly that "the results of van der Merwe et al. have not been replicated," and separately notes that intense resistance training itself can raise these same androgenic hormones independent of any supplement (Antonio et al. 2021, JISSN). A broader look at the testosterone literature found 13 studies with 278 total participants examining creatine's hormonal effects, of which only 3 studies covering 60 participants reported any testosterone increase, while the remaining 10 studies covering 218 participants found no change at all (Jinfiniti Precision Medicine literature summary). If testosterone itself rarely moves, the substrate available for conversion to DHT rarely increases either, which undercuts the mechanism the 2009 paper proposed.

The 2021 ISSN position stand addresses hair loss directly

Antonio and colleagues' 2021 paper, "Common Questions and Misconceptions About Creatine Supplementation: What Does the Scientific Evidence Really Show?," published in the Journal of the International Society of Sports Nutrition, dedicates a full section to the hair loss question as one of its core myths addressed, alongside water retention, kidney function, and whether creatine is an anabolic steroid (Antonio et al. 2021, JISSN). Its conclusion: "the current body of evidence does not indicate that creatine supplementation increases total testosterone, free testosterone, DHT or causes hair loss/baldness." The panel also points out that even in the original 2009 data, the DHT and DHT-to-testosterone values that increased remained within the normal clinical range for healthy adult men throughout the study.

Kreider 2017: the broader safety review

Kreider and colleagues' 2017 International Society of Sports Nutrition position stand, "Safety and Efficacy of Creatine Supplementation in Exercise, Sport, and Medicine," reviewed decades of creatine research, including studies with doses up to 30 g per day sustained for as long as 5 years in both healthy and clinical populations (PubMed, 2017). It concluded there is no evidence that creatine supplementation increases the incidence of musculoskeletal injury, dehydration, muscle cramping, gastrointestinal upset, or kidney dysfunction in healthy individuals, and it did not identify hair loss as a substantiated risk anywhere in that safety record. Hair loss is conspicuous by its absence from a document specifically built to catalog what creatine's real, evidence-backed downsides are.

The 2025 trial that finally measured hair, not just hormones

The most direct answer available came out in 2025. Lak and colleagues ran a 12-week, randomized, double-blind, placebo-controlled trial in 38 resistance-trained men, comparing 5 g per day of creatine monohydrate against a maltodextrin placebo, and it is the first study to measure actual hair follicle health alongside hormone levels rather than hormones alone (Journal of the International Society of Sports Nutrition, 2025). The result: no significant differences between the creatine and placebo groups in DHT levels, the DHT-to-testosterone ratio, or any hair growth parameter, including hair density, follicular unit count, and cumulative hair thickness. Total testosterone increased in both groups over the 12 weeks, a change the authors attribute to resistance training itself rather than to creatine, since it happened independent of which supplement group a participant was in. The paper's own language is direct: the findings "provide strong evidence against the claim that creatine contributes to hair loss."

The genetic component: creatine is not the variable that decides this

Pattern hair loss is substantially heritable, driven by androgen receptor sensitivity and 5-alpha-reductase activity that vary by genetics, not by supplement use. If you have a strong family history of male or female pattern baldness, particularly on both sides of your family, you carry a meaningfully higher lifetime probability of experiencing it regardless of what you take. If you do not carry that genetic susceptibility, the current evidence does not show creatine pushing a resistant follicle into miniaturization. This is the same logic that applies to normal training itself: resistance exercise raises testosterone and DHT acutely, and nobody frames a heavy squat session as a hair loss risk, because the underlying genetic sensitivity of the follicle, not the transient hormone bump, is what actually determines the outcome.

Practically, the honest framework looks like this. If you have a strong family history of early, progressive pattern baldness and are personally anxious about it, it is reasonable to discuss creatine with a doctor or dermatologist before starting, monitor your own hairline over time, and stop if you notice accelerated shedding, understanding that this is a precautionary choice rather than one mandated by trial data. If you do not have that family history, the current evidence, an unreplicated 2009 hormone study versus a 2025 randomized trial that directly measured hair and found nothing, does not support avoiding creatine for this reason.

The side effects creatine actually has

It is worth being precise about where creatine's real, documented downsides sit, since they are unglamorous compared to the hair loss myth but are the ones actually supported by data. Water retention is the most consistent finding: creatine draws water into muscle cells during the loading phase, which can show up as 1 to 2 kg of scale weight gain in the first one to two weeks, an effect the 2021 ISSN review confirms is real but temporary and intracellular rather than the bloating some people fear (Antonio et al. 2021, JISSN). Mild gastrointestinal discomfort, including bloating or loose stool, occurs in some users, particularly when a large loading dose like 20 to 25 g per day is taken in a single sitting rather than split across several smaller doses through the day. Both the 2017 Kreider position stand and the 2021 Antonio review found no credible evidence for the other commonly feared effects, including kidney damage, dehydration, or cramping, in healthy individuals using recommended doses.

If you are adding creatine into a broader training and nutrition plan, the practical dosing that avoids most of the GI complaints is a straight 3 to 5 g per day of creatine monohydrate, taken any time of day, with no loading phase required, since loading only changes how quickly you reach saturated muscle stores, not whether you get there. That number is small and stable enough to build into a fixed daily habit alongside the rest of your nutrition targets, which is where a tool like the Scinergy macro calculator is useful for keeping your protein and calorie targets dialed in while a supplement like creatine does its slower, separate job of supporting training volume, which is covered in detail in our guide to weekly set volume for muscle gain.

A worked example: putting the risk in context

Take a hypothetical 85 kg lifter with no family history of early pattern baldness, using 5 g per day of creatine monohydrate for a year as part of a structured hypertrophy program. The 2009 van der Merwe protocol used a loading dose of 25 g per day, five times higher than this lifter's steady maintenance dose, for only 7 days, and even at that higher dose produced a DHT change that stayed within normal clinical range and was never connected to any hair outcome. The 2025 Lak trial used the same 5 g per day dose this lifter is taking, sustained for 12 straight weeks, directly measured hair density and follicle counts, and found zero measurable difference from placebo. Extending a null result at 12 weeks to a full year is not proof of anything, since no trial has run that long with hair as an endpoint, but it is the closest real data point available, and it points the same direction: no detected effect at the dose and duration most people actually use.

Meanwhile, that same lifter's actual muscle growth over the year depends far more on total training volume and protein intake than on creatine's marginal contribution to any single hormone pathway. Working out roughly how much protein supports that goal is covered in our protein for muscle gain article, and the two together, protein target from that guide plus a sensible weekly set count, do more for this lifter's physique over a year than any decision about creatine's hormonal side effects ever will.

Bottom line

The creatine and hair loss claim traces back to one study, from 2009, of 20 rugby players, that measured serum DHT and testosterone and never once looked at hair. That study found a real, statistically significant, but modest and still within-normal-range increase in DHT, and it has never been replicated in over 15 years since. The 2021 ISSN position stand and the 2017 Kreider safety review both treat hair loss as an unsubstantiated concern rather than a documented side effect, and a 2025 randomized trial that finally measured actual hair follicle outcomes found no difference between creatine and placebo. None of this proves creatine can never affect hair in any individual, and if you have a strong family history of pattern baldness and personal concern about it, a conversation with a dermatologist before starting is a reasonable, low-cost precaution. But for most lifters without that specific risk factor, the evidence available today does not support treating hair loss as an established creatine side effect, especially set against the well-documented, unglamorous ones, water retention and mild GI discomfort, that the research actually does confirm.