Adrenaline is a hormone and neurotransmitter produced in the adrenal glands that helps the body respond to stress by increasing heart rate, blood pressure, and strength. It has the chemical formula C9H13NO3 and contains carbon, nitrogen, oxygen, and hydrogen. While normally inactive in the adrenal glands, adrenaline causes excitement and enjoyment when released but can also cause side effects like lightheadedness and headaches after it wears off.