Does the age you start shaving have any effect on regrowth?

Many people think that if you start shaving early, your hair will grow quicker and thicker. But the rate at which your hair grows is determined by heredity and the hormone testosterone. Adolescent boys have the most testosterone and as a result, their hair grows very quickly. This is also the age that most men start shaving, so you may think that it was the shaving that caused you to sprout more hair, when in actual fact it was the increased levels of testosterone.