Use of CBD — cannabidiol, the non-psychoactive component in cannabis — has exploded in the last few years. But while it's marketed as a solution for stress, anxiety, insomnia, and pain, the Food and Drug Administration can't say it's safe. NPR health correspondent Allison Aubrey helps parse the science behind a new set of government warnings about CBD. Follow host Maddie Sofia on Twitter @maddie_sofia. Email the show at shortwave@npr.org.