Hormones

A hormone is a chemical that the body uses to start processes in certain parts of the body. Hormones are produced in different endocrine glands and are moved around the body in the blood.

Boys start to produce the male sex hormone testosterone and girls start to produce the female sex hormone oestrogen during puberty. These hormones cause the boy’s body to develop into a man’s body, and the girl’s body to develop into a woman’s body.