Epinephrine, also called adrenaline, is both a hormone and a neurotransmitter. As a hormone, it’s made and released by your adrenal glands, which are hat-shaped glands that sit on top of each kidney. As a central nervous system neurotransmitter, it’s a chemical messenger that helps transmit nerve signals across nerve endings to another nerve cell, muscle cell or gland cell.
Epinephrine is part of your sympathetic nervous system, which is part of your body’s emergency response system to danger — the “fight-or-flight” response. Medically, the flight-or-flight response is known as the acute stress response.
Epinephrine is also called a catecholamine, as are norepinephrine and dopamine. They’re given this name because of a certain molecule in its structure. As a hormone, epinephrine is made from norepinephrine inside of your adrenal gland.