Creatine is the most-read topic on our blog, and the most frequent question underneath it is not about endurance. It goes like this: “won't my hair fall out?” The question lives in every chat where supplements are discussed, and in September it surfaced again along with the fashion for creatine as a nootropic. Let us look at where it came from and what the only study that actually measured hair has shown.

Where the fear comes from

From one single study. In 2009 van der Merwe and colleagues (Clinical Journal of Sport Medicine) gave 20 student rugby players in South Africa the classic protocol: 25 g of creatine a day for 7 days (loading), then 5 g a day for 14 days. The design was decent — double-blind crossover, with a six-week washout between arms.

Testosterone did not change. But dihydrotestosterone (DHT) rose by 56% after the loading week and stayed 40% above baseline after the maintenance phase. The DHT-to-testosterone ratio: +36% and +22% respectively, p < 0.01.

DHT is the very androgen to which follicles are sensitive in androgenetic alopecia. From there the chain completed itself: creatine → DHT → baldness. Three important details usually get left out:

hair was not measured in this study at all — neither density, nor thickness, nor shedding;
the DHT values, even after rising, stayed within the reference range;
in sixteen years the result has never once been replicated. According to the review by Antonio and colleagues (JISSN, 2021), of twelve other studies that looked at testosterone in people taking creatine, ten found no change and two found small, physiologically insignificant ones; nobody else measured DHT until 2025.

What the new RCT did

Lak and colleagues (Journal of the International Society of Sports Nutrition, 2025) were the first to test not the intermediary hormone but the endpoint — the hair itself.

Design. 45 resistance-trained men aged 18–40, randomised to creatine monohydrate 5 g/day or placebo, 5 g of maltodextrin, for 12 weeks. Diet and training as usual, with no intervention. Before and after: blood for total testosterone, free testosterone and DHT; hair assessed by trichogram (microscopy of plucked hairs by growth phase) and by the FotoFinder system — digital trichoscopy that counts hair density, the number of follicular units and cumulative hair thickness on a fixed patch of scalp. 38 people made it to the end.

Result. There was no group × time interaction for any hormone or any hair measure (p > 0.05).

Total testosterone rose over 12 weeks in both groups — by 124 ± 149 ng/dl on creatine and by 216 ± 203 on placebo; free testosterone fell slightly in both. That is an effect of time and training, not of the supplement.
DHT and the DHT/testosterone ratio — no differences between groups.
Hair density, number of follicular units, cumulative thickness — no differences.

The authors call this the first direct evidence against a link between creatine and hair loss. The wording is strong, but let us look at what it covers and what it does not.

What this proves and what it does not

It proves: three months of a standard maintenance dose in young men shifts neither DHT nor objective hair measures. For most runners and triathletes that is exactly the scenario in which they take creatine — 3–5 g a day without loading.

Loading was not tested. The DHT jump in the rugby players happened at 25 g/day. The new study had no such phase. The question “what does a week at 20–25 g do” remains open — although even in van der Merwe's study DHT was already heading down by the end of the maintenance phase.

12 weeks is not long for alopecia. A hair's growth cycle runs for years, and androgenetic baldness develops over years. Trichoscopy is sensitive to early shifts (the share of telogen hairs, miniaturisation), but three months do not rule out a slow effect in the genetically predisposed. No such study exists in either direction.

38 people can only pick up a medium or large effect. A small shift in a subgroup with a family history of baldness would slip past a sample of this size.

Only men aged 18–40 doing resistance training. There are no data on women, on the over-40s or on endurance sports — although there is no visible mechanism by which the type of sport would change how follicles respond.

What to do

If baldness runs in your family — creatine is not the lever that will switch it on or off. Genetics and age weigh incomparably more.
If you have noticed more shedding while training — before blaming the tub, check ferritin, TSH and energy balance: telogen shedding 2–3 months after an iron deficiency or a sharp calorie deficit is far more common in runners than the hypothetical creatine effect.
Still worried — skip the loading phase. 3–5 g a day saturates the muscles in 3–4 weeks, and loading was the only regimen in which DHT moved at all.
The nootropic regimen is the same 5 g/day; the new RCT covers it completely.

The bottom line

The fear comes from a single 2009 study: 20 rugby players, DHT +56% after a week at 25 g, hair not measured, result never replicated.
The 2025 RCT: 38 men, 5 g/day, 12 weeks, trichogram + FotoFinder — no differences from placebo in DHT, or in hair density, thickness or follicle count.
Limitations: no loading phase, three months against a process that takes years, young men only.
For the standard 3–5 g/day regimen that runners use, there are no better data than these right now — and they are negative.

Sources: Lak M., Forbes S.C., Ashtary-Larky D., Dadkhahfar S., Robati R.M., Nezakati F., Khajevandi M., Naseri S., Gerafiani A., Haghighat N., Antonio J., Tinsley G.M. “Does creatine cause hair loss? A 12-week randomized controlled trial”. Journal of the International Society of Sports Nutrition, 2025;22(sup1):2495229. DOI: 10.1080/15502783.2025.2495229 · van der Merwe J., Brooks N.E., Myburgh K.H. “Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players”. Clinical Journal of Sport Medicine, 2009;19(5):399–404. DOI: 10.1097/JSM.0b013e3181b8b52f · Antonio J. et al. “Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?”. Journal of the International Society of Sports Nutrition, 2021;18:13. DOI: 10.1186/s12970-021-00412-w