PurposeTitle IX, § 921 of the Food and Drug Administration (FDA) Amendments Act of 2007 requires the FDA to mine data on a regular basis, using its adverse events database, the FDA Adverse Event Reporting System, to identify potential signals of serious risks/new safety information. This review of the FDA's quarterly web-posted results is the first to document the contributions of the program to maintaining the continued safe use of approved pharmaceutical drugs/biologics and the lessons that have emerged from this rich experience. MethodsDetails on proprietary prescription drugs/biologics, generic prescription drugs, and over-the-counter drugs were downloaded from the quarterly posts that begin in first quarter of 2008. Key information was tabulated, including proprietary and generic names of products or classes of products, the identified potential signals of serious risks, the labeling-decision category (updated, no action is necessary at this time, or evaluating the need for regulatory action), the labeling section (Warnings and Precautions, Adverse Reactions, Drug Safety Communications, Contraindications, or Boxed Warnings), and estimated times to updated decisions. FindingsSince the beginning of the FDAAA Section 921 posting requirement, the FDA has posted 555 potential signals of serious risk or new safety information. Of these, there have been 262 posts (47%) that resulted in decisions requiring updated product labeling, 75 posts (14%) that resulted in decisions that no action was necessary, and 218 posts (39%) indicating that the FDA was evaluating the need for regulatory action. Of the 262 posts that required updating one or more sections of a product label, there was a preponderance of Warnings and Precautions, with 172 (66%); followed by Adverse Reactions, with 114 (44%); Drug Safety Communications, 44 (18%); Contraindications, 27 (10%); and Boxed Warnings, 19 (7%). The median times to update decisions were 12 months for Warnings & Precautions, Adverse Reactions, and Boxed Warnings, and 11 months for Contraindications. ImplicationsImportant themes from the present analysis include the following: (1) nearly 80% of posts resulted in updated product labeling; (2) 20% of decisions concerned classes of proprietary and generic drug/biologic products; (3) product-use errors, such as name confusion, continue to be important; (4) the safe use of pharmaceuticals in children is gaining attention but still has a long way to go; and (5) drug–drug interactions are of continuing concern. The FDA Amendments Act § 921 program will continue to have an important place in the future of pharmacovigilance practices.