Follicle-stimulating hormone (FSH) is a chemical in your body that helps to create babies. When you grow up big and strong, your body will start making babies and FSH is one of the helpers that does that job.
Do you know what your eggs are? Girls have these little balls in their bellies called eggs, and boys have little swimmers called sperm. When you want to have a baby, one of the eggs from a girl and one of the sperm from a boy will join together, and that starts to create a baby.
But before that can happen, a girl's body needs to get ready to give an egg to the boy's sperm. And that's where FSH comes in. FSH tells the girl's body to start making a bigger and stronger egg, so that it can be ready to join with the boy's sperm.
And that's not all FSH does. It also helps the boy's body to make more sperm, so that there will be lots of little swimmers to try and join with the girl's egg.
So, to sum it up, FSH is a special chemical in your body that helps make babies. It tells the girls' and boys' bodies to get ready to make eggs and sperm, so that they can try and join together to create a baby.