The combination of the narcotic heroin and stimulant cocaine mixed together and injected together in a single shot. When administered IV, the speedball produces the best rush/high in the world of drugs and is the most deadly of procedures as far as getting loaded. Highly addictive. Beyond destructive. Will bring any addict to their knees. It will call you and lure you, lie to you and kill you. Like alcohol and pills as well. This is the worst though. That is why it is the best.
"Man, my habit and tollerance were getting out of control. I was shooting about eight to ten speedballs a day just to stay high and not get sick."