Blocks of hash on a table. Hashish is made from the flowering tops of female Cannabis sativa plants, which are rich in resins containing THC, the active chemical that produces a high. (The leaves and other parts of the plant are used to make another drug, marijuana, which has a lower THC content. ) The tops are dried and then compressed into a variety of forms, such as balls, cakes, or cookie-like sheets. Pieces are then broken off, placed in pipes, and smoked. The Middle East, North Africa, Pakistan, Nepal and Afghanistan are major sources of hashish.