FDA Adverse Event Reporting System (FAERS)

The FDA Adverse Event Reporting System (FAERS) is the U.S. Food and Drug Administration’s database of adverse event and medication error reports submitted for drugs and biologics that are already approved and on the U.S. market. It is FDA’s central tool for post-marketing safety surveillance — ongoing monitoring of a product’s real-world safety profile after it has cleared premarket review, as opposed to the safety monitoring that happens inside a clinical trial before approval.

For research administrators and clinical trial staff, the operationally important distinction is where FAERS sits relative to the trial lifecycle: it is downstream of approval, separate from the investigator/sponsor safety reporting obligations that apply to an investigational product still under an active protocol (governed by ICH GCP and, in the U.S., IND safety reporting under 21 CFR 312.32). An adverse event occurring in an ongoing trial of an unapproved product is not a FAERS report; a report about an approved product already prescribed in routine practice is.

Two report streams feed FAERS

FAERS data comes from two structurally different sources, and understanding which stream a given report came from matters when interpreting the database:

• Mandatory manufacturer reports. Holders of an approved New Drug Application (NDA), Abbreviated New Drug Application (ANDA), or Biologics License Application (BLA) are legally required to submit adverse event reports they become aware of, on regulatory timelines set out in 21 CFR 314.80 (drugs) and 21 CFR 600.80 (biologics) — serious and unexpected events on an expedited basis, other events periodically.
• Voluntary reports via MedWatch. FDA’s MedWatch program (FDA Form 3500) lets healthcare professionals, patients, and consumers report a suspected adverse event or product problem directly to FDA, without going through the manufacturer. These reports are voluntary and make up a smaller share of total FAERS volume than mandatory manufacturer reports, but they are an important independent channel — particularly for events a manufacturer may not otherwise learn about.

Both streams flow into the same underlying database, which historically also absorbed FDA’s earlier Adverse Event Reporting System (AERS) predecessor.

The public dashboard and quarterly data extracts

FDA has made de-identified FAERS data publicly accessible in two forms: an interactive, web-based public dashboard that lets a user query the data by product, event, or time period without needing database or programming tools, and downloadable quarterly data extract files (in ASCII or XML format) intended for users who want to run their own relational-database analysis. Both draw from the same underlying report pool and have historically been refreshed on a quarterly cycle as new reports are processed and become ready for public release.

What FAERS does not tell you

The single most important interpretive caveat, and one FDA states explicitly about its own database: the presence of an adverse event report in FAERS does not establish that the product caused the event. Reports reflect a suspected association at the time of submission, not a confirmed causal relationship, and are subject to well-known limitations common to spontaneous-reporting systems — underreporting, duplicate reports, reporting bias (more severe or novel events are more likely to be reported), and the absence of a defined denominator (FAERS does not by itself indicate how many patients were exposed to a product, only how many adverse events were reported). FDA and outside researchers use FAERS data as one input into broader signal-detection and pharmacoepidemiologic analysis, not as a standalone causality determination.

FAERS and the wider adverse-event reporting landscape

FAERS is the U.S. analog to spontaneous post-market adverse event systems maintained by other national and regional regulators, most notably the European Medicines Agency’s EudraVigilance. Within FDA’s own remit, FAERS has historically been scoped to drugs and biologics, with medical devices captured separately (MAUDE) and vaccine adverse events reported through the CDC/FDA-co-managed Vaccine Adverse Event Reporting System (VAERS). As of early-to-mid 2026, FDA has reportedly been consolidating FAERS with several of these adjacent legacy systems onto a new unified platform, the Adverse Event Monitoring System (AEMS), intended to eventually process reports for all FDA-regulated product types on one dashboard. The mandatory-vs-voluntary reporting mechanics and legal reporting obligations described above continue to apply to the underlying data either way; given how recent this platform transition is, confirm the current system name and access point directly on fda.gov before citing specifics or linking a live URL.

Frequently asked questions

Who can submit a report to FAERS?

Manufacturers are required to submit reports they become aware of about their own approved products; healthcare professionals, patients, and consumers may voluntarily submit reports through MedWatch. Both feed the same database.

Does a FAERS report mean the drug caused the adverse event?

No. FDA states explicitly that a report’s presence in FAERS does not establish causation — it reflects a suspected association reported at the time, not a confirmed causal link.

How is FAERS different from IND safety reporting?

IND safety reporting (21 CFR 312.32) applies to an investigational product still under an active clinical trial, before approval. FAERS applies to products already approved and marketed — it is post-market surveillance, not trial-specific safety reporting.

How often is FAERS data updated?

FAERS data has historically been released publicly on a quarterly cycle, through both the interactive public dashboard and downloadable quarterly data extract files; verify current update cadence given FDA’s 2026 platform consolidation described above.