Wegovy Vision Loss Risks 5 Times Higher Than Ozempic: Study

The dose-specific response discovered by Canadian researchers is considered a strong sign that semaglutide actually causes vision problems.

Emerging evidence suggests that side effects of Wegovy, the higher-dose weight loss version of Ozempic, may carry a greater risk of vision problems, leading researchers to suspect that higher doses of the drug could increase the likelihood of optic nerve damage.

Wegovy and Ozempic are prescription medications manufactured by Novo Nordisk, both of which rely on the active ingredient semaglutide. Ozempic was approved first in 2017 as a Type 1 diabetes treatment. Later, when the drug was linked to significant weight loss benefits, the manufacturer released a larger-dose version called Wegovy, which is specifically approved for use as a diet drug.

Since their introduction, the medications, as well as other so-called GLP-1 medications like Mounjaro, Zepbound and Trulicity, have been linked to a variety of side effects not originally mentioned on warning labels. These include stomach paralysis intestinal obstruction, hair loss and other concerns.

However, a number of studies have specifically linked Ozempic and Wegovy to an increased risk of a rare eye condition known as non-arteritic anterior ischemic optic neuropathy (NAION), which can cause sudden and often permanent vision loss, blurred vision or complete blindness.

Earlier this year, a study published in JAMA Ophthalmology found that patients taking Ozempic or Wegovy faced roughly twice the risk of developing NAION compared to those treated with SGLT2 inhibitor diabetes medications. 

Now, Canadian researchers are warning that Wegovy carries an even higher risk of vision problems than Ozempic, suggesting what is known as a dose-specific response, which is a strong indicator that the medications are the source of the vision problems.

Led by Dr. Edward Margolin from the University of Toronto, the new study, published in The BMJ on March 10, involved an analysis of data gleaned from the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) from December 2017 through December 2024, which included 30,668,530 incident reports.

Of those 31,774 involved semaglutide-based drugs like Ozempic, Wegovy and Rybelsus. They compared those to reports involving other diabetes and weight loss drugs, including other GLP-1 medications like Mounjaro and Zepbound.

According to the findings, patients taking Wegovy were about five times more likely to develop ischemic optic neuropathy (ION), sometimes called an eye stroke, than those using Ozempic, representing the strongest safety signal among the medications analyzed. No cases of ION were associated with Rybelsus, the oral tablet form of semaglutide, while both Ozempic and Wegovy are administered as injections.

Because Wegovy is often prescribed at higher dosages than Ozempic, researchers determined that the increased Wegovy vision loss problems are likely dose-specific, meaning that the higher the dose of semaglutide, the higher the risk of vision problems. This is a strong indicator of a causal connection, the researchers noted.

Researchers found no indication that Mounjaro or other non-semaglutide drugs increased ION vision loss risks.

“Semaglutide, in any formulation, was the only agent significantly associated with ION, with the strongest signal for Wegovy followed by Ozempic. These findings extend our prior global analysis and, whereas previous studies identified only an agent-specific association, this study provides the first evidence of a formulation- and dose-dependent ION risk, with the strongest association observed for Wegovy.”

– Dr. Edward Margolin, University of Toronto

The researchers called for more studies into the potential vision loss problems linked to the medications to better help doctors know how to individualize GLP-1 care in the most safe and effective manner.

Ozempic and Wegovy NAION Lawsuits

Along with growing concerns over GLP-1 vision loss side effects have come dozens of Ozempic and Wegovy NAION lawsuits filed throughout the U.S. court system by individuals who say they suffered permanent vision damage after using the medications.

All of the federal claims have been consolidated before U.S. District Judge Karen Marston for coordinated discovery and pretrial proceedings as part of a multidistrict litigation (MDL) in the Eastern District of Pennsylvania. Judge Marston is expected to plan a series of bellwether trials in the near future which will give the parties the opportunity to see how juries respond to evidence and testimony likely to be used in numerous similar cases, should they go to trial.

In addition to the vision loss lawsuits, Judge Marston is also overseeing thousands of other Ozempic lawsuits, Wegovy lawsuits and Mounjaro lawsuits filed by a separate group of plaintiffs over stomach paralysis side effects, which are also expected to go through bellwether trial litigation.

While the outcomes of these trials are not binding on other cases, they will be closely watched by Ozempic and Wegovy vision loss attorneys as verdicts could pave the way for a potential settlement agreement. However, if no such settlement is reached, Judge Marston would likely begin remanding the lawsuits back to the various federal courts where they were first filed to be prepared for trial dates.

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