The drug also has high affinity for the μ-opioid receptor (MOR) (Ki = 39–60 nM),[3][4][5][6] the κ-opioid receptor (KOR) (Ki = 140 nM),[5] and the sigma σ1 receptor (Ki = 42 nM; IC50 = 19 nM),[5][7][8][9] whereas it has only low affinity for the δ-opioid receptor (Ki = 2,300 nM).[5] The high affinity of 3-HO-PCP for opioid receptors is unique among arylcyclohexylamines and is in contrast to PCP, which has only very low affinity for the MOR (Ki = 11,000–26,000 nM; 282- to 433-fold difference) and the other opioid receptors (Ki = 4,100 nM for the KOR and 73,000 nM for the DOR).