Ozempic, Wegovy Kidney Side Effects Highlighted in New Study

The study’s findings add to growing concerns about the popular diabetes and weight loss drug’s effects on the kidneys.

A new study warns that side effects of Ozempic and Wegovy appear to be linked to an increased risk of kidney injuries, while their competitors, Mounjaro and Zepbound, are not.

According to findings published in Preprints.org (PDF) on October 2, there have been a “disproportionate” number of acute kidney injuries (AKIs) among users of the popular weight loss and diabetes drugs, following a review of reports submitted to the U.S. Food and Drug Administration’s (FDA) Adverse Event Reporting System (FAERS). The findings have not yet been peer-reviewed and officially published.

The drugs all belong to a class of medications known as glucagon-like peptide-1 (GLP-1) receptor agonists, the most popular of which is Ozempic (semaglutide), which was originally approved in 2017 for the treatment of type 2 diabetes. After the medications weight loss benefits led to widespread off-label use of Ozempic, the drug maker introduced a version under the brand name Wegovy, which contains the same active ingredient, but is approved as a diet drug.

Eli Lilly’s competing drug, Mounjaro (tirzepatide), is also approved for diabetes treatment, with a weight loss counterpart marketed as Zepbound. Other drugs in the GLP-1 class include Saxenda, Byetta, Victoza, Trulicity, Rybelsus and others.

As popularity of the drugs has soared over the past few years, concerns have emerged about a number of side effects being reported among users, particularly involving gastrointestinal problems like stomach paralysis and bowel obstructions, as well as vision loss. However, while many of these problems are class-wide, some side effects appear to be specific to particular drugs. 

As a result, the manufacturers have faced a growing number of Ozempic lawsuits, Mounjaro lawsuits, Wegovy lawsuits and other GLP-1 claims, each raising similar allegations that in the drug makers’ rush to promote the benefits associated with the treatments, they failed to adequately disclose potentially serious side effects some users experience.

In the new study, Dr. Ayush Gandhi of the University of Texas conducted a retrospective pharmacovigilance analysis using FAERS data from January 2022 through September 2025, identifying reports where the drugs were listed as the primary suspect in cases of acute kidney injury, renal failure, renal impairment, and other kidney-related complications.

Although Mounjaro and Zepbound were associated with more than twice as many adverse event reports as Ozempic and Wegovy, the rate of acute kidney injury (AKI) was actually lower. According to the data:

• Mounjaro and Zepbound (tirzepatide):
  • 92,807 total U.S. adverse event reports
  • 432 involved AKI, accounting for 0.47% of cases
    
• Ozempic and Wegovy (semaglutide):
  • 41,065 total U.S. adverse event reports
  • 440 involved AKI, accounting for 1.07% of cases — more than double the AKI rate of tirzepatide

According to the findings, there were 16 deaths, six disabilities, 11 life-threatening events, and 209 hospitalizations linked to Eli Lilly’s drugs. Comparatively, there were 28 deaths, 11 disabilities, 36 life-threatening events, and 243 hospitalizations linked to semaglutide. The number of reported adverse events typically only account for a fraction of actual side effects users are experiencing.

“In summary, semaglutide continues to show a disproportionate signal for AKI in FAERS, while tirzepatide does not. Although absolute risk is low, the signal supports careful hydration counseling and monitoring for patients starting semaglutide.”

– Dr. Ayush Gandhi, Department of Medicine, University of Texas

The findings come on the heels of a study published in late August in JAMA Oncology, which warned that the entire class of GLP-1 medications could increase kidney cancer risks by more than a third.

GLP-1 Side Effects Lawsuits

The studies have been published amid more than 2,800 product liability lawsuits brought throughout the federal court system, each indicating GLP-1 manufacturers failed to provide adequate warning that the diabetes and weight loss drugs could cause severe gastrointestinal problems.

Given common questions of fact and law raised throughout the complaints, all GLP-1  lawsuits have been centralized in a multidistrict litigation (MDL) in the Eastern District of Pennsylvania, where U.S. District Judge Karen Marston is overseeing coordinated discovery and pretrial proceedings. As part of that process, the court will eventually select a small group of representative cases to serve as early “bellwethers,” providing insight into how juries may respond to recurring evidence and testimony.

First, however, Judge Marston has ordered both sides to resolve several issues that could have broad implications for the litigation, including preemption and general causation. Once those matters are addressed, the MDL is expected to proceed with preparing the first set of cases for jury consideration. While the verdicts will not directly determine the outcome of other GLP-1 claims, they are likely to shape settlement negotiations.

If the parties do not reach a GLP-1 settlement agreement after the bellwether trials, Judge Marston is likely to begin remanding the cases back to their original courts for individual trial dates.