Hormones trigger facial hair growth in a maturing male physical & sexual systems systems
Explanation:
When a male attains puberty the androgen's take control and regulate the male physique development. This puberty changes triggers the sex hormones.
After 12 years their testosterone hormones start working on the hair follicle which replaces the thin tiny vellus hair to thick black and hoarse hairs. Eventually the hormone felicitates growth of hair in his face, under arm and leg.
Men with levels of testosterone and dihydro testosterone or DHT is the major driving factor that causes the growth of facial hair.
