Compounded GLP-1 Drugs Show Dramatically Higher Rates of Side Effects and Quality Problems Than FDA-Approved Versions | Research

The takeaway

Compounded GLP-1 agonists were linked to 6× higher suicidality reports, 49× more preparation errors, and 2.35× higher hospitalization odds compared to brand-name versions in FDA adverse event data.

48.92× preparation errors
Compounded GLP-1 products had nearly 49 times the odds of preparation errors reported to the FDA compared to brand-name versions

What the researchers found

Compounded GLP-1 receptor agonists were associated with significantly higher rates of adverse events compared to FDA-approved versions across the board. Key findings from 81,078 FAERS reports (707 compounded):

- Suicidality: 6.34× higher odds with compounded products

- Cholecystitis (gallbladder inflammation): 3.39× higher odds

- Abdominal pain: 2.84× higher odds

- Hospitalization: 2.35× higher odds

- Preparation errors: 48.92× higher odds

- Contamination: 19× higher odds

- Compounding/manufacturing issues: 8.51× higher odds

Compounded products did show lower odds of dosing errors (0.24×) and administration errors (0.29×).

Why it matters

Millions of people have turned to compounded semaglutide and tirzepatide due to brand-name drug shortages and high costs. This is the first large-scale pharmacovigilance analysis comparing compounded vs. FDA-approved GLP-1 drugs using FAERS data, and the results are alarming. The nearly 49-fold increase in preparation errors and 19-fold increase in contamination reports suggest serious quality control problems. The 6.34-fold increase in suicidality reports is particularly concerning and warrants urgent investigation.

The numbers in context

81,078 total FAERS reports · 707 compounded · ROR suicidality 6.34 · ROR cholecystitis 3.39 · ROR abdominal pain 2.84 · ROR hospitalization 2.35 · ROR preparation errors 48.92 · ROR contamination 19.00 · 2018–2024 data

How the study worked

Retrospective pharmacovigilance analysis of the FDA Adverse Event Reporting System (FAERS) from 2018 to 2024. Researchers compared adverse event reports for compounded versus non-compounded liraglutide, semaglutide, and tirzepatide. Reporting odds ratios (RORs) with 95% confidence intervals were calculated using logistic regression to adjust for confounders.

Who was studied

Adults reporting adverse events from GLP-1 receptor agonists (liraglutide, semaglutide, tirzepatide) to the FDA FAERS database, 2018–2024

What this study cannot tell us

FAERS is a voluntary reporting system subject to reporting bias — compounded products may attract more reports due to media attention and FDA scrutiny. The study cannot prove causation, only association. Compounded product users may differ systematically from brand-name users (e.g., no insurance, different dosing). The relatively small compounded sample (707 reports) limits the precision of some estimates. Underreporting is inherent in all voluntary adverse event databases.

How to read the evidence

Moderate evidence from a large pharmacovigilance database analysis. FAERS data is real-world and captures signals across tens of thousands of patients, but voluntary reporting introduces bias. The study used adjusted odds ratios to control for confounders, strengthening the analysis. However, the observational design cannot prove causation.

When this study was published

Published in 2026 using FAERS data from 2018–2024. This is the most current analysis available on compounded GLP-1 safety and directly relevant to ongoing FDA regulatory decisions.

The bigger picture

The compounded GLP-1 market has exploded as a response to shortages and high prices of brand-name drugs. The FDA has struggled to regulate this space, and this study provides the strongest pharmacovigilance signal yet that compounded peptide drugs carry measurably higher risks. As the FDA considers ending the shortage designation for semaglutide (which would shut down most compounding), this data will likely fuel both sides of the debate — those arguing compounded drugs are dangerous and those arguing patients need affordable access regardless.

Questions still open

Is the 6.34× suicidality signal driven by contamination, incorrect dosing, or the compounded drug itself?
How much of the elevated adverse event reporting is due to surveillance bias versus genuine safety differences?
Should compounding pharmacies making GLP-1 agonists be held to the same quality standards as FDA-approved manufacturers?

Common questions

Are compounded GLP-1 drugs safe?

This study suggests they carry measurably higher risks than FDA-approved versions. Compounded products showed higher rates of side effects (abdominal pain, nausea, suicidality), more hospitalizations, and dramatically more quality problems (contamination, preparation errors). However, FAERS data has limitations — it can't prove these problems are caused by compounding itself versus other factors like different patient populations or reporting bias.

Why are compounded GLP-1 drugs so much cheaper than brand-name versions?

Compounding pharmacies don't go through the full FDA approval process, don't run expensive clinical trials, and can make copies of drugs during shortages. They also don't have the marketing and distribution costs of major pharmaceutical companies. However, this study suggests the cost savings may come with reduced quality control — preparation errors were nearly 49 times more common in compounded products.

Read the original research

Safety analysis of compounded GLP-1 receptor agonists: a pharmacovigilance study using the FDA adverse event reporting system.

Expert opinion on drug safety, 25(3), 581-588

View on PubMed ↗Publisher’s paper ↗

Citation

McCall, Kenneth L; Mastro Dwyer, Keri A; Casey, Ryan T; Samana, Tasnia N; Sulicz, Ewa K; Tso, Susannah Y; Yalanzhi, Emma R; Piper, Brian J. (2026). Safety analysis of compounded GLP-1 receptor agonists: a pharmacovigilance study using the FDA adverse event reporting system.. Expert opinion on drug safety, 25(3), 581-588. https://doi.org/10.1080/14740338.2025.2499670