Mustache and beard normally begin to grow in males during their initial puberty period, and develops in the puberty stage that is between 11 and 21 years of age. Depending on genetic conditions and environment, the process of facial hair growth may vary in individuals. Male facial hair growth is triggered by testosterone, a strong androgenic hormone produced by the testes. The amount of testosterone hormone in a man’s body is responsible for quality of facial hair, normally more testosterone hormone means more facial hair in a man.
Today growing mustache, or beard for that matter, is a personal taste; however, a wide range of customs and religious beliefs, across cultures and countries, have been associated with facial hair since ancient time.