Warning Letters — What to Expect
A warning letter is FDA's primary enforcement communication — it is public, searchable, and commercially significant.
What triggers a warning letter?
- Inadequate response to 483 observations
- Systemic MDR failures
- Off-label promotional claims
- Failure to submit required reports
Key facts
- Must respond in writing within 15 business days
- Response should address each 483 observation and explain corrective actions taken or planned. Failure to respond adequately or failure to promptly correct violations may result in escalated enforcement action, including seizure, injunction, or criminal prosecution.
- Published publicly on FDA's website
- Visible to customers, partners, and other regulators globally