Human hair growth
The three stages of hair growth are the anagen, catagen, and telogen phases. Each strand of hair on the human body is at its own stage of development. Once the cycle is complete, it restarts and a new strand of hair begins to form. The rate or speed of hair growth is about 1.25 centimetres or 0.5 inches per month, or about 15 centimetres or 6 inches per year.
Facial hair
Great apes such as orangutan males seem to have facial hair as well. In chimpanzees and bonobos, facial and body hair become sparser in adulthood due to the aging process, which is in stark contrast to humans, whose facial and body hair become stronger. Because infant great apes have thicker "facial" (as well as body) hair than their older counterparts, it is not androgenic but part of the fur complex. The sensitivity to androgens seems to have been acquired by humans on the gene KRT37 relatively recently.