The hair-loss rumor that followed a supplement for 15 years

Plenty of people stay away from things that might help them because of something they heard once. A friend at the gym. A comment section. A headline nobody actually read.

This one is about creatine, one of the most studied sports supplements there is, and a fear that has followed it since 2009.

Where the fear started

In 2009, researchers in South Africa gave 20 male college rugby players creatine for three weeks [1]. They measured two hormones: testosterone, and dihydrotestosterone (DHT), which is linked to male pattern hair loss.

Testosterone did not change. DHT went up. Because DHT and hair loss are connected, the conclusion seemed obvious to a lot of people online.

The problem: the study never measured anyone's hair. And the DHT result has not been replicated.

When someone finally measured hair

In 2025, a randomized, placebo-controlled trial followed 45 resistance-trained men aged 18 to 40 for 12 weeks [2]. Half took 5 grams of creatine monohydrate a day. Half took a placebo. Everyone kept training as usual.

This time the researchers measured hair directly: count, density, thickness, follicle health and growth phase, using standard scalp imaging. They found no significant changes in any hair measure, and DHT did not change differently between the groups [2].

What it does not show

Both studies were in men. We could not find a trial that measured hair in women taking creatine. The 2025 trial lasted 12 weeks and did not account for family history of hair loss.

Why it matters to you

The point is not the supplement. The point is how easily one small, unreplicated result can turn into something everyone "knows". Ask what was actually measured. You will be surprised how often the answer is "not that".

If hair loss runs in your family and you want personal advice, that is a good conversation to have with your doctor.