Black Box Warning
The FDA's most serious labeling warning, boxed at the top of a drug's Prescribing Information.
A black box warning, officially called a Boxed Warning, is the strongest safety warning the FDA can require on a prescription drug's label. It sits in a bordered box at the top of the PI, ahead of everything else, and it's reserved for risks that are serious or life-threatening: a risk of death, a risk that requires special monitoring, or a risk severe enough that it changes how a prescriber should weigh the drug against alternatives.
For promotional content, a boxed warning isn't background information to skim past. Fair balance requirements can mean the warning, or a clear reference to it, needs to appear with a prominence that matches the claims being made elsewhere in the piece, and the exact expectation varies by format. Reviewers treat a boxed-warning drug differently from one without, and content built for one rarely transfers cleanly to the other.