controlled substance
(redirected from controlled substance, a)controlled substance
A drug whose availability is limited by law. A: "I thought you could just find your medication on the shelf at the pharmacy." B: "Nah, I'm on a new one, and it's a controlled substance, so I have a prescription for it." I'm really glad I didn't follow in my brother's footsteps and become addicted to controlled substances.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.