Carfentanil is a synthetic opiate 100 times more potent than fentanyl. It's typically used to tranquilize elephants and other large animals.
Ingesting poppy seeds—which come from opium poppies—in the days before taking a drug test can lead to a false positive result.
Scientists believe drugs take over mechanisms in the brain which form memories, potentially offering one explanation for substance abuse and addiction.
Using crypto-currency and an underground network of nearly-untraceable websites, people get what they need.
The Homeland Security secretary says heroin, cocaine and meth are bigger problems.
The plan will focus on treating addicts rather than punishing them and targeting high-level suppliers for arrest.