Heroin, or diamorphine, is an opiate substance that acts on the central nervous system. Heroin can be used medicinally for coughs, insomnia
relief, or diarrhea
. However, due to its extremely addictive properties, heroin is more commonly taken as a recreational drug
, and is illegal to sell. Heroin plunges those who abuse it into a state of extreme drowsiness and causes a loss of perception of pain or external stimuli.