receptor agonist that has been described to be functionally selective towards G protein and away from ?-arrestin2 pathways. However, recent reports highlight that, rather than functional selectivity or 'G protein bias', this agonist has low intrinsic efficacy. In vivo, it has been reported to mediate pain relief without tolerance nor gastrointestinal side effects.

The delta opioid receptor agonists SNC80 and ARM390 demonstrate