Usage Examples
- FDA is asking for a boxed warning on hepatotoxicity, so we need agreed wording before the supplement goes in.
- Keep the Highlights version under 20 lines; the full box sits at the top of the prescribing information.
- We are filing this as a changes-being-effected supplement to strengthen the boxed warning, not holding it for the annual report.
What is Black Box Warning (Boxed Warning)?
Black Box Warning is FDA's most serious prescription drug labeling warning, a bordered box at the start of the prescribing information reserved for contraindications or serious warnings that may lead to death or serious injury.
Black Box Warning is what FDA reaches for when ordinary warning text will not change prescribing behavior. Prescribing information runs dozens of pages, and a risk that can kill a patient cannot compete for attention inside it. The regulation therefore lets FDA pull specific contraindications and serious warnings out of the body of the label and force them into a bordered box at the top.
Black Box Warning covers a narrow band of risk: contraindications or serious warnings, particularly those that may lead to death or serious injury. Everything else stays in Contraindications or Warnings and Precautions. The box is not a summary of the safety profile, not a REMS, and not a restriction on prescribing. It is a display requirement applied to information that already appears elsewhere in the label.
Black Box Warning text is negotiated, not drafted freely. FDA proposes or demands the box, the sponsor responds with wording, and the agreed text lands in two places: a concise summary in Highlights and the full box at the top of the prescribing information. After approval, sponsors add or strengthen the box through a changes-being-effected supplement once the causal evidence meets the labeling standard.
Not to be confused with
- Warnings and Precautions
- the label section that holds clinically significant adverse reactions generally. The boxed warning is a small subset lifted out of that section (or out of Contraindications) and displayed in a box, and it must point back to the fuller entry.
- Contraindication
- states a situation in which the drug must not be used at all. A boxed warning may or may not describe a contraindication; the box is a presentation requirement, not a prohibition on use.
- REMS
- an enforceable risk management program with elements FDA can require, such as prescriber certification or restricted distribution. A boxed warning changes only what the label says and imposes no distribution or enrollment obligations.
- Medication Guide
- patient-directed labeling handed out at dispensing. A boxed warning is prescriber-directed and lives in the professional prescribing information.
The obligations attach to the label, not to the product.
What you must do
- 1Present contraindications or serious warnings that may lead to death or serious injury inside a box when FDA requires it21 CFR 201.57(c)(1)
- 2Head the box with the word WARNING in uppercase, briefly explain the risk, and refer out to the more detailed entry in the Contraindications or Warnings and Precautions section21 CFR 201.57(c)(1)
- 3Carry a concise summary of the boxed warning in Highlights, capped at 20 lines21 CFR 201.57(a)(4)
- 4Submit a changes-being-effected supplement to add or strengthen a warning once the evidence of a causal association satisfies the standard for inclusion in labeling21 CFR 314.70(c)(6)(iii)(A)
Common mistakes
Treating the box as new information
the boxed warning has to cross-reference detailed text in Contraindications or Warnings and Precautions. A box that asserts something the body of the label does not support is a labeling defect and costs a review cycle on the supplement.
Blowing the 20-line Highlights limit
teams draft the full box first and paste it into Highlights. Highlights carries a concise summary capped at 20 lines; over-length copy comes back as a formatting deficiency.
Waiting for FDA to ask
sponsors sit on a maturing safety signal assuming the agency will initiate the change. The changes-being-effected route exists so the sponsor can move first once the causal evidence meets the 21 CFR 201.57(c) standard; sitting on the signal turns a routine supplement into a question about why the sponsor did not act.
When This Matters
- FDA is asking for a boxed warning on hepatotoxicity, so we need agreed wording before the supplement goes in.
- Keep the Highlights version under 20 lines; the full box sits at the top of the prescribing information.
- We are filing this as a changes-being-effected supplement to strengthen the boxed warning, not holding it for the annual report.
Frequently Asked Questions
Yes. Boxed warning is the regulatory term used in 21 CFR 201.57; black box warning is the informal name clinicians and journalists use for the same thing, taken from the bold border around the text. FDA labeling, guidance, and supplements use boxed warning exclusively.
