Epinephrine is the chemical signature of fear and anxiety, released during alerting or fearful experiences.

“Epinephrine doesn't just create a desire to move and alertness. It is also the chemical signature of fear and anxiety. It's what's released from our adrenal glands when we experience something that's fearful or alerting. So if a car suddenly screeches in front of us, or we get a troubling text message, adrenaline is deployed into our system. Adrenaline is epinephrin, those are equivalent molecules. And epinephrin isn't just released from our adrenals it's also released within our brain.”