 I'm Paul Stevens. This is Fox News. A fraction of a raindrop, three grains of salt, add up to 100 times more potent than morphine. The tiniest amount of illegal fentanyl is all it takes to cause an overdose. Fentanyl can be mixed into heroin, cocaine, press pills, meth, and other drugs. It could be in your drugs, and you wouldn't be able to see it, taste it, or smell it.