Pronunciation: (en-DOR-fin)

One of several substances made in the body that can relieve pain and give a feeling of well-being. Endorphins are peptides (small proteins) that bind to opioid receptors in the central nervous system. An endorphin is a type of neurotransmitter.

Source: NCI Dictionary of Cancer Terms

2006-02-21 Date last modified: 2009-05-01