How to Access FDA Adverse Event Databases for Safety Monitoring

How to Access FDA Adverse Event Databases for Safety Monitoring
by Derek Carão on 9.12.2025

The U.S. Food and Drug Administration (FDA) runs one of the largest public safety databases in the world: the FAERS (FDA Adverse Event Reporting System). It’s not a secret system. It’s not locked behind paywalls. Anyone can access it-researchers, doctors, patients, journalists, even curious students. But knowing where to look and how to read the data is where most people get stuck.

Every year, about two million reports of bad reactions to drugs and biologics pour into FAERS. These aren’t lab results or clinical trial data. They’re real-world stories: a patient who had a seizure after taking a new antidepressant, a nurse who noticed unusual bleeding after a blood thinner was switched, a parent whose child developed a rash after a vaccine. The FDA doesn’t confirm these reports are caused by the drug. But when patterns emerge across thousands of reports, that’s when safety signals start to light up.

What’s in the FAERS database?

FAERS collects Individual Case Safety Reports (ICSRs). Each one includes basic details: patient age and gender (first initials only, no full names), the drug(s) involved, the adverse event described, and who reported it-doctor, pharmacist, patient, or manufacturer.

The adverse events aren’t written in plain English. They’re coded using MedDRA (Medical Dictionary for Regulatory Activities), a standardized terminology system with over 80,000 terms. For example, "heart attack" might be coded as "Myocardial Infarction," and "dizziness" as "Vertigo." This helps the system group similar events across millions of reports. But if you don’t know MedDRA, you’ll see a wall of technical codes instead of clear symptoms.

Reports come from two main sources: pharmaceutical companies (about 75%) and healthcare providers or patients through the MedWatch program (25%). Companies are legally required to report. Anyone else can submit voluntarily. That’s why the data is messy. Some reports are detailed. Others have missing dates, unclear drug names, or no outcome listed. The FDA says about 30% of reports have incomplete or inconsistent data.

Three ways to access FAERS data

You don’t need to be a data scientist to start exploring. Here are the three public ways in:

  1. FAERS Public Dashboard - The easiest entry point. It’s a web tool with drop-down menus and charts. You can pick a drug like "Metformin," choose an adverse event like "Acute Kidney Injury," and see how many reports came in over the last year. It shows trends, patient age groups, and report sources. No download needed. No coding. You can get useful insights in under an hour.
  2. Quarterly Data Extracts - If you want raw data, the FDA releases ASCII and XML files every three months. These files are huge-1 to 5 gigabytes each. You need software like Python, R, or Excel with plugins to open them. This is for people who want to run their own analyses. But be warned: the file format changes slightly each quarter, and MedDRA codes aren’t always easy to map to plain language.
  3. OpenFDA API - This is the developer’s route. You can query FAERS data in JSON format using simple web requests. For example, you can ask: "Show me all reports for Ozempic with the term 'pancreatitis' in the last 12 months." You’ll need basic programming skills, but there are tutorials online. It’s faster than downloading massive files and lets you build custom tools.

What the dashboard can and can’t tell you

The FAERS Public Dashboard is great for spotting red flags. In 2022, a patient advocacy group used it to find a pattern: people taking a common diabetes drug and an antidepressant together were reporting sudden drops in blood sugar more often than expected. That led to a new warning on the label. That’s the power of transparency.

But here’s the catch: FAERS doesn’t tell you how many people took the drug. It only tells you how many people reported a problem. If 10 million people take a drug and 100 report a side effect, that’s 0.001%. But if only 1,000 people take it and 100 report it, that’s 10%. Without knowing the denominator, you can’t calculate true risk. That’s why the FDA says: "FAERS data alone cannot prove a drug causes an adverse event."

Another issue is reporting bias. Serious events get reported more often. If a drug causes mild nausea, patients might not bother. But if it causes liver failure, doctors will report it. Also, manufacturers report more about their own drugs than competitors’. So if Drug A has 1,000 reports and Drug B has 500, it might mean Drug A is riskier-or that 10 times more people use Drug A.

Researcher analyzing MedDRA codes and XML data streams in a dim lab with statistical visualizations.

How experts use FAERS data

Academic researchers use FAERS to find signals for rare side effects. Clinical trials often involve 5,000-10,000 people. But once a drug hits the market, millions use it. That’s when rare reactions-like a one-in-50,000 chance of a heart rhythm problem-start showing up. FAERS helped uncover the link between certain antibiotics and tendon rupture, and between statins and memory issues, years before formal studies confirmed them.

Dr. Robert Ball from the FDA says data mining in FAERS is like "finding needles in a haystack using magnets." Algorithms look for unexpected spikes in certain drug-event pairs. If "Lisinopril" and "Angioedema" show up together way more than expected, that’s a signal. But the algorithm doesn’t know why. That’s where human judgment comes in. Researchers then check medical records, look for other studies, and see if the pattern holds across different populations.

Some researchers combine FAERS with other data sources. The FDA’s Sentinel Initiative links FAERS with insurance claims and electronic health records. That helps fill the denominator gap-now they can say, "Of 2 million people taking this drug, 1,200 had this reaction." That’s a real rate, not just a count.

Challenges and frustrations

Despite its value, FAERS is hard to use well. Many users report spending 40 to 60 hours just learning how MedDRA works. One researcher at Johns Hopkins said: "The dashboard lets you see the forest. But to understand the trees, you need a PhD in coding systems."

Another problem: the quarterly data releases aren’t always consistent. Sometimes a field changes name. Sometimes the XML structure shifts. That breaks automated scripts. And the FDA doesn’t always update its documentation fast enough.

Industry users face another hurdle. If you’re a pharmaceutical company, you have to submit reports using the E2B(R3) standard-a complex XML format. It took many companies over a year to fully switch after the FDA mandated it in January 2024. The learning curve is steep. Many rely on third-party software to handle the submissions.

And then there’s the silence. Not every report gets reviewed. With two million reports a year, the FDA can’t investigate them all. Only the strongest signals trigger action. That means some real risks might slip through-especially for drugs taken by older people, pregnant women, or those with multiple conditions, who are often underrepresented in clinical trials.

A giant data-tree in a city plaza, citizens submitting adverse event reports under a glowing FDA eagle.

What’s next for FAERS?

The FDA isn’t standing still. By late 2024, they plan to launch a new API that lets you query the dashboard’s charts and filters directly-no downloading files needed. By mid-2025, they’re adding natural language processing so you can type in plain English like, "Show me reports of confusion after taking Zoloft," and get results without knowing MedDRA codes.

They’re also testing ways to link FAERS with real-world data from hospitals and pharmacies. If successful, this could turn FAERS from a passive reporting tool into an active safety monitoring system.

But the biggest change might be cultural. More researchers, patient groups, and even journalists are using FAERS. That pressure for transparency is forcing the FDA to make the system more user-friendly. What was once a tool for regulators is now becoming a public resource.

Getting started: What you need to do

If you’re a student, journalist, or concerned patient:

  • Go to the FAERS Public Dashboard (no login needed).
  • Try searching for a drug you’re curious about.
  • Look at the trend chart. Is the number of reports going up?
  • Check the patient age group. Is it mostly older adults?
  • Read the FDA’s warning: "This does not prove the drug caused the event."

If you’re a researcher or data analyst:

  • Download the latest quarterly data extract from the FDA’s FAERS page.
  • Use Python with pandas and MedDRA mapping files to clean the data.
  • Apply statistical filters to spot disproportionate reporting (like the Proportional Reporting Ratio).
  • Compare your findings with published literature.

For both groups: join the FDA’s quarterly webinars. They’re free. Attendance is around 250-300 people each time. You’ll hear directly from the people who manage the system.

Is FAERS worth it?

Yes-but only if you understand its limits. FAERS won’t give you definitive answers. It won’t tell you if a drug is safe or dangerous. But it will show you where the questions are. It’s a starting point, not an endpoint.

Think of it like a smoke alarm. It doesn’t tell you where the fire is. But if it goes off, you know to look.

Can I trust the FDA adverse event reports?

You can trust that the reports are real and submitted by real people, but not that they prove causation. FAERS collects unverified reports. A report saying "I took Drug X and got dizzy" doesn’t mean Drug X caused the dizziness. It could be coincidence, another medication, or an underlying condition. The FDA uses FAERS to find patterns, not to confirm individual cases.

Do I need to be a programmer to use FAERS data?

No. The FAERS Public Dashboard works in any browser and requires no coding. You can explore trends, filter by drug or symptom, and download charts with a few clicks. But if you want to analyze raw data files (like the quarterly XML downloads), you’ll need basic programming skills in Python, R, or SQL. Most academic users spend 40-60 hours learning how to handle the data properly.

Why do some drugs have more reports than others?

More reports don’t always mean more danger. Popular drugs get used by millions, so even rare side effects will show up more often. A drug taken by 10 million people might have 500 reports. A rare drug taken by 10,000 might have 50. The key is looking at the rate, not the count. The FDA uses statistical methods to adjust for usage volume, but that’s not visible in the public dashboard. Always check how many people are estimated to be using the drug.

Can I report an adverse event myself?

Yes. Anyone can report an adverse event through the FDA’s MedWatch program. Go to the FDA’s MedWatch website and fill out the online form. You don’t need a doctor’s note. Even if you’re unsure whether the drug caused the issue, report it. The more data, the better the FDA can spot patterns. Your report could help prevent harm to others.

How often is the FAERS data updated?

The FDA releases new data quarterly-every three months. The public dashboard updates with the latest quarter’s reports within 30 days after the end of each quarter. Raw data files (ASCII and XML) are posted at the same time. If you’re tracking a specific drug, check the FDA’s FAERS page around the 15th of January, April, July, and October for the latest updates.

Is FAERS data used outside the U.S.?

Yes. Researchers and regulators worldwide use FAERS as a key resource because it’s one of the most comprehensive publicly accessible databases. The WHO’s VigiBase includes FAERS data, and European agencies reference it when evaluating drug safety. However, the European Medicines Agency (EMA) restricts direct public access to its own database, EudraVigilance, making FAERS uniquely valuable for global transparency.

What’s the difference between FAERS and OpenFDA?

FAERS is the original database that collects all adverse event reports. OpenFDA is a free API that gives you structured, machine-readable access to FAERS data in JSON format. Think of FAERS as the library, and OpenFDA as the digital catalog you can search programmatically. OpenFDA pulls from FAERS and other FDA databases, so it’s not a separate system-it’s a smarter way to access the same data.

Can FAERS detect side effects that weren’t found in clinical trials?

Absolutely. Clinical trials involve thousands of people under controlled conditions. FAERS tracks millions of people in real life-older adults, pregnant women, people with multiple health conditions, and those taking multiple drugs. That’s how rare side effects like liver damage from a new diabetes drug or heart rhythm issues from a common antibiotic were first noticed. FAERS is designed to catch what trials miss.