I spent years as an FDA Investigator drafting and issuing 483 Inspectional Observations to noncompliant firms. I read dozens of 483 responses as a Compliance Officer and noticed that companies across food, supplements, and cosmetics write bad 483 responses for the same reason: they do not know what the agency is actually looking for. The 15-day window is real When an investigator hands you a 483 at the close of an inspection, you have 15 business days to submit a written resp