Hormones are special chemicals your body makes to help it do certain things - like grow up! Hormones are important when you start to go through puberty, which is when you begin developing into an adult. During this time, you're loaded with hormones that tell your body that it's time to start changing.
Insulin is an important hormone. It regulates the amount of sugar in your blood. That sugar, called glucose, is the body's main source of fuel.