JWH 251 is a cannabimimetic indole that shows a high affinity for the central cannabinoid (CB1) receptor with a Ki value of 29 nM and a comparatively modest affinity for the peripheral cannabinoid (CB2) receptor (Ki = 146 nM). JWH 251 stimulates GTPγS binding of CB1 and CB2 receptors with EC50 values of 29 and 8.3 nM, respectively.
