The role of reproductive hormones in puberty


Puberty is the stage in life when a child's body develops into an adult's body. The changes take place gradually, usually between the ages of 10 and 16, but sometimes before or after this age.

A hormone is a chemical substance, produced by a gland and carried by the blood, which alters the activity of specific target organs (and is then destroyed by the liver). Changes occur at puberty because of hormones:

  • testosterone – a hormone produced by the testes which controls the development of male secondary sexual characteristics, for example, facial hair
  • oestrogen – a hormone produced by the ovaries which controls the development of female secondary sexual characteristics, for example breast development

Secondary sexual characteristics appear during puberty and are not present at birth.

Changes during puberty

Boys onlyBoys and girlsGirls only
Voice breaksPubic hair growsVoice deepens gradually
Hair grows on face and bodyUnderarm hair growsHips get wider
Body becomes more muscularSexual organs grow and developBreasts develop
Testes start to produce sperm cellsOvaries start to release egg cells - menstruation starts