1-[2-(Trifluoromethyl)phenyl]-3-azabicyclo[3.1.0]hexane Hydrochloride-d5 is labelled 1-[2-(Trifluoromethyl)phenyl]-3-azabicyclo[3.1.0]hexane Hydrochloride (T791395), an isomer of 1-[3-(Trifluoromethyl)phenyl]-3-azabicyclo[3.1.0]hexane Hydrochloride (T791390) which is a nonnarcotic analgesic agent.