mu Opioid R/OPRM1 Small Molecules and Peptides

The powerful effects of opiate are mediated through the opioid receptors located on the plasma membrane of neurons and other peripheral cells. There are at least 3 types of opioid receptors, mu, kappa, and delta, each with a distinct pharmacologic profile. The mu opioid receptor is the primary site of action for the most commonly used opioids, including morphine, heroin, fentanyl, and methadone.