But that doesn't mean a man who suffers from boy face—meaning, he can't cultivate a beard—isn't wise or manly. So why can't some men grow facial hair? The diversity of facial hair growth depends on genetics. Men start to develop facial hair—which is regulated by testosterone —during their pubescent stage, and it doesn't fully mature until they reach their early twenties.
Some men can't grow beards and facial hair; a dermatologist explains - Business Insider
Being able to properly groom your beard is easier said than done, and growing that rugged look takes some work for just about every guy. Even though there might not be a single trick to develop that stunning beard that drives ladies crazy, there are simple steps to increase testosterone and beard growth regardless if you want that full beard or sexy goatee. It is often said that genetics has the last word when it comes to beard growth. The truth is that the hormones responsible for beard growth are testosterone and dihydrotestosterone DHT. While testosterone is responsible for hair follicle priming, DHT promotes the linear growth of facial hair.
Narrator: Look at that beard: the density, the thickness. It's what a beard is supposed to be! Not this: This is my beard, if you even want to call it a beard. This footage was taken after I let it grow for two weeks.
Waiting for a beard to grow in can feel a lot like watching grass grow. The younger you are, the longer it may take you to hit your beard goals. Many men will sport the beginnings of a mustache and a few sprigs of chin hair years before the rest of their beard starts to surface.