Definition: Hormones

Hormones

Hormones are chemical substances that act like messenger molecules in the body. After being made in one part of the body, they travel to other parts of the body where they help control how cells and organs do their work. For example, insulin is a hormone that's made by the beta cells in the pancreas. When it's released into the blood, insulin helps regulate how the cells of the body use glucose (a type of sugar) for energy.