I remember there was a kid at my school who could grow a thick beard at the age of 15. Everyone noticed because it was unusual for a white boy to have such thick facial hair at that age. He also had a very deep voice and thick body hair.
A few years later I saw him again when he was 19 and he had lost at least 70% of the hair on his head and he looked about 40.
There’s a very simple reason for this particular type of premature hair loss. That kid had very large quantities of the male androgen hormone called Dihydrotestosterone (DHT).
DHT is the hormone that makes hair grow thicker on your face and body. It has the reverse effect in the scalp. It binds to receptors in the follicles making them either turn into thick dark hairs (in the face and body) or the reverse in the scalp.
If you have zero DHT you can’t experience male pattern baldness. You could still experience the rarer form of hair loss, alopecia areata, but not male pattern baldness (MPB), because MPB is caused by DHT.
However, you may have noticed that some men have very thick facial and body hair and yet they still don’t lose the hair in their heads or even recede at all. The example I always use are Alec Baldwin. He has tons of body hair, caused by high DHT levels, yet he still has a thick hair on his head.
So, why don’t all men with high DHT levels lose their hair?
I suspect the reason is partly genetics but more so to do with stress. I suspect men who have very high DHT levels and also have high stress levels are the ones that lose their hair very young.
A good example of this exact thing is actor Dwayne Johnson. Dwayne Johnson has taken bucket loads of steroids for most of his life, which causes very high DHT levels. He’s also said several times in interviews that he suffers from anxiety.
I suspect the combination of mega high DHT and high stress hormone levels caused by anxiety are the reason Dwayne lost his hair at a young age.