The prohibition against drug use has boosted black market research on finding new, more powerful drugs that can be transported easier and more safely than existing ones. Because they are more powerful, a smaller amount can be profitable, as well as more dangerous and addictive than older drugs. Hence, drug prohibition has fueled the refinement of heroin (from much less addictive precursors) and the invention of crack cocaine (a cheaper, more addictive and more dangerous derivative of cocaine).