Why does 16-year-old beard grow so fast after being cut?

Beard, commonly known as beard, refers to the hair that grows on men's upper lip, chin, cheeks, cheeks or neck. If we want to distinguish carefully, "Hu" originally refers to the hair that grows on the mouth, while the upper lip is called "moustache" (in Cantonese, moustache, moustache and two-lipped beard), the chin is called "goatee" and the temple is connected with the chin. Men after puberty generally have beards. Beard grows faster than hair, which is the result of androgen. The more vigorous the reproductive function, the faster the beard grows. Beard has more blood vessels than hair roots, and nutrients are easy to obtain. Therefore, the beard that has just been shaved will grow back in a few days.