Dylar is intended to remove the fear of death. However, the drug does not work properly and extended use sometimes results in insanity. Extended users interpret spoken words and metaphor as actual actions and events. In an instance presented in the novel, the spoken phrase "hail of bullets" causes a Dylar-using character to panic, drop to the floor and crawl to shelter.
The drug is only produced on an experimental, highly secretive basis and comes in the form of a small white pill with an insoluble polymer coating containing only a minute hole. During digestion water enters through the polymer coating and the active ingredients begin to dissolve, but can only leave the polymer coating through the tiny laser drilled hole, creating a highly controlled release of the chemical. When empty, the coating collapses in on itself and passes harmlessly out through the digestive tract.