This project analyzes serious adverse events associated with GLP-1 receptor agonists using the FDA Adverse Event Reporting System (FAERS) database.
GLP-1 receptor agonists such as semaglutide, liraglutide, dulaglutide, exenatide, lixisenatide, and tirzepatide are widely prescribed for the treatment of type 2 diabetes and obesity. These medications improve glycemic control by stimulating insulin secretion, suppressing glucagon release, and slowing gastric emptying.
Because the use of GLP-1 therapies has increased rapidly worldwide, monitoring their real-world safety profile has become increasingly important. Pharmacovigilance databases such as FAERS provide valuable information about adverse drug reactions reported in clinical practice.
This project conducts a retrospective pharmacovigilance analysis of FAERS reports from 2025 (Q1–Q4) to identify patterns of adverse events and serious clinical outcomes associated with GLP-1 receptor agonists.
• Analyzed 250,449 FAERS adverse event reports from 2025 (Q1–Q4)
• Identified 124,062 serious adverse event reports associated with GLP-1 receptor agonists
• Conducted retrospective pharmacovigilance analysis using the FDA FAERS database
• Identified top adverse reactions, including nausea, vomiting, and impaired gastric emptying
• Examined serious clinical outcomes such as hospitalization, life-threatening events, and death
• Compared adverse event patterns across GLP-1 medications including semaglutide, tirzepatide, dulaglutide, and liraglutide
• Produced 7 data visualizations to illustrate adverse event distributions and drug-specific reporting patterns
• Performed the full workflow using R, ggplot2, and FAERS public-use data
To describe and compare serious adverse events reported for GLP-1 receptor agonists in the FAERS database and explore whether drug type and report characteristics are associated with serious outcomes.
RQ1:
What types of serious outcomes (hospitalization, death, life-threatening events, etc.) are reported for GLP-1 receptor agonists in FAERS, and how frequently does each outcome occur?
RQ2:
Which adverse reactions are most frequently associated with serious outcomes among GLP-1 drug reports?
RQ3:
Do patterns of serious adverse events differ across individual GLP-1 medications?
H1:
Hospitalization will be the most frequently reported serious outcome among GLP-1 adverse event reports.
H2:
The distribution of serious adverse events will differ across GLP-1 drugs.
Source: FDA Adverse Event Reporting System (FAERS)
This analysis used FAERS public datasets from:
2025 Q1 – 2025 Q4
FAERS is a spontaneous reporting system used by the FDA for post-marketing drug safety monitoring.
Reports are submitted by:
- Healthcare professionals
- Pharmaceutical manufacturers
- Patients and consumers
Because FAERS contains millions of adverse event reports from diverse patient populations, it is widely used for pharmacovigilance and epidemiologic drug safety research.
| Metric | Value |
|---|---|
| FAERS data used | 2025 Q1 – Q4 |
| Total reports analyzed | 250,449 |
| Serious reports | 124,062 |
| Non-serious reports | 126,387 |
| Most reported GLP-1 drug | Mounjaro |
| Second most reported drug | Ozempic |
| Most common adverse reaction | Incorrect dose administered |
| Second most common reaction | Nausea |
| Most common serious outcome | Other serious outcome |
| Second most common serious outcome | Hospitalization |
These summary statistics provide an overview of the FAERS dataset analyzed in this project.
The analysis was conducted using R.
Key analytical steps included:
- Importing FAERS quarterly datasets (2025 Q1–Q4)
- Cleaning and merging FAERS files
- Filtering reports involving GLP-1 receptor agonists
- Removing duplicate case reports
- Extracting adverse event preferred terms (PT)
- Identifying serious outcomes
- Generating descriptive statistics
- Visualizing reporting patterns using ggplot2
This workflow allows identification of commonly reported adverse reactions and serious clinical outcomes associated with GLP-1 medications.
The analysis identified several important pharmacovigilance patterns:
• Gastrointestinal symptoms such as nausea, vomiting, and diarrhea were among the most frequently reported adverse reactions.
• The most commonly reported serious outcomes were other medically significant outcomes and hospitalization.
• Life-threatening events, disability, and death were relatively uncommon compared with other serious outcomes.
• The largest number of adverse event reports were associated with semaglutide and tirzepatide products, reflecting their widespread clinical use.
These findings are consistent with previously published pharmacovigilance studies examining GLP-1 receptor agonists.
FAERS is a spontaneous reporting system and therefore has several limitations:
- Underreporting of adverse events
- Reporting bias and stimulated reporting
- Duplicate or incomplete reports
- Lack of denominator data for drug exposure
- Inability to establish causal relationships
Therefore, results should be interpreted as reporting patterns rather than true incidence rates.
- R
- data.table
- ggplot2
- Excel
- FDA FAERS Public Use Data
Asmita Thapa
Master of Public Health (MPH)
Biostatistics & Epidemiology
This project demonstrates:
- Pharmacovigilance analysis using FAERS drug safety data
- Handling of large public health datasets
- Epidemiologic analysis using R
- Data visualization for drug safety research
- Reproducible public health research workflows