The compound in cannabis responsible for its intoxicating, and many of its medical, effects. The most common compound produced in cannabis varieties that have been bred for recreational and medicinal use.The activated form of THC, Δ9-THC, causes the intoxicating feelings generally associated with consuming cannabis and being ‘high’. THC causes intoxication by binding to the CB1 receptor in our bodies. It also binds to the CB2 receptor and stimulates our immune system. Mnemonic device: The High Causer.