speedballing refers to mixing herion and cocaine. both substances can be mixed together and snorted. or injected if you're extremely dumb. apparently it gives the feeling of falling down an escalator. it confuses the heart, because herion is a "downer" and cocaine is an "upper." so herion slows the heart down while cocaine speeds it up. its an easy way to have a heart attack if you aren't careful. yet to be experinced haha.
last night, i decided to try speedballing dude. it was fuckin ridiculous; i didn't even know what was going on.