What are Endorphins? Endorphins are a type of hormone produced by the brain and nervous system to relieve stress and pain. They work similarly to a class of drugs called opioids. According to Jeffrey M. Cohen, PsyD, Instructor of Medical Psychology at Columbia University Medical Center, Opioid receptors are part of a system that controls pain and reward. By activating the opioid receptors, endorphins can temporarily affect aspects…