Why the hormone that grows your Movember moustache can also thin your hairline

Every November, men are encouraged to grow a moustache in support of the annual Movember campaign, which raises awareness of men's health, including mental health and prostate and testicular cancer. Movember also puts facial hair in the spotlight, offering an opportunity to explore an intriguing connection between the hair on a man's face and the hair on his head: the same hormone that encourages a moustache to grow can contribute to a receding hairline.

That hormone is called dihydrotestosterone (DHT), a potent androgen formed when the enzyme 5-alpha-reductase converts testosterone. How it affects hair growth depends on where the follicles are located. In beard and moustache follicles, DHT stimulates thicker hair growth. In certain scalp follicles, however, it shortens the growth phase, causing hairs to become progressively finer and shorter. Over time, this can lead to recession at the temples and thinning around the crown.

“Men often assume that a receding hairline means they have higher-than-normal testosterone levels, but this is generally not the case,” says Dr Kashmal Kalan, Medical Director at Alvi Armani. “Male pattern hair loss is influenced by several genes inherited from either side of the family, which affect how follicles respond to DHT. This is also why a man's hair-loss pattern cannot reliably be predicted by looking at his father or maternal grandfather alone.”

This difference in how facial and scalp follicles respond to DHT is known as the androgen paradox. Researchers Shigeki Inui and Satoshi Itami explored the phenomenon in their 2013 paper, Androgen actions on the human hair follicle: perspectives, published in Experimental Dermatology. It helps explain why beard density offers little indication of what may be happening on a man's scalp. A man can have substantial facial hair while experiencing significant scalp thinning, because facial and scalp follicles respond differently to DHT.

The differences are evident across the scalp itself. Follicles at the temples and crown are more vulnerable to DHT-driven miniaturisation, while those in the donor region are generally less affected. This relative resistance underpins the principle of donor dominance, demonstrated by dermatologist Norman Orentreich in his landmark 1959 paper, Autografts in Alopecias and Other Selected Dermatological Conditions. His work showed that transplanted follicles retain important growth characteristics of their original location, even when moved to a region affected by hair loss.

“For a transplant to deliver a durable result, we need to look beyond the number of available grafts. Hair that is already showing signs of miniaturisation may continue to thin after transplantation, which can compromise the result over time,” adds Dr Kalan. “The stability of the surrounding, non-transplanted hair also needs to be considered, as it can continue to thin even after a successful transplant.”

The same principles of follicle selection and placement apply when restoring facial hair. Scalp follicles can be transplanted to suitable facial areas to restore beard growth, while beard-to-scalp grafts may be considered for selected patients with limited scalp donor availability.

“Beard hair generally retains its thicker calibre after transplantation and can supplement scalp coverage, although finer scalp follicles are usually preferred for the leading hairline. Matching the characteristics of the transplanted hair to the recipient area is important for achieving a natural-looking result,” concludes Dr Kalan.

As Movember puts men's health in the spotlight, Dr Kalan encourages men to pay attention to changes in their hair without jumping to conclusions about the cause. A moustache will not make a hairline recede, and a receding hairline does not automatically indicate a hormone imbalance.