KNT-127 is a potent δ-opioid receptor agonist that crosses the blood-brain barrier (BBB). KNT-127 is highly selective to the δ receptor, with K i values of 0.16, 21.3 and 153 nM for δ, μ and κ receptors, respectively. KNT-127 increases the release of dopamine and L-glutamate in the striatum, nucleus accumbens, and prefrontal cortex. KNT-127 has analgesic, antidepressant and antianxiety activities.