Hormones

Hormones are chemical messengers made by one part of the body (like the brain or the ovary) to affect another bit of the body. Like S Club 7, they’re all different but – hey! – they’ve all gotta work together to make it happen.

Hormones aren’t just involved in sex – thyroxine is made in the thyroid gland in the neck, and controls how fast most of the cells in the body work. But without sex hormones, babies wouldn’t grow up, we wouldn’t want sex, girls wouldn’t release the egg each month and the fertilised egg would never develop into a baby. So then where would we be? Dead, that’s where.

The main female sex hormones are oestrogen and progesterone. They are mostly produced in the ovaries, but their production is controlled by hormones from the brain. The ovaries in women also make a small amount of the male sex hormone – testosterone. Men make 10 times as much testosterone as women, and women make 10 times more oestrogen / progesterone than men.

When body builders take steroids, they are actually taking sex hormones. Overdosing like this allows you to put on extra muscles for a bit, but they also damage your genitals long-term.

Boys stages of puberty ...
Girls stages of puberty ...