Endorphins are neurotransmitters produced by your brain and nervous system during times of stress or pain. They interact with opiate receptors in your brain reducing your perception of pain and triggering positive feelings.
A neurotransmitter that contributes to feelings of well-being and happiness.
Opiate Receptors: These are specific proteins in the brain with which endorphins (and some drugs) interact, causing a reduction in the sensation of pain.