μ-opioid receptor

![Active and inactive μ-opioid receptors[1]](/uploads/202501/28/Mu-opioid_receptor3458.png)
The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta-endorphin, but a low affinity for dynorphins. They are also referred to as μ-opioid peptide (MOP) receptors. The prototypical μ-opioid receptor agonist is morphine, the primary psychoactive alkaloid in opium.