FDA issues warning on weight loss drugs over potential vision loss risk

The eye condition, known as non-arteritic anterior ischemic optic neuropathy (NAION), can cause significant vision impairment. The FDA’s investigation began following a 2024 medical paper that linked the condition to patients taking semaglutide, the active ingredient in Novo Nordisk’s Ozempic and Wegovy.

Dr. Joseph Rizzo, a neuro-ophthalmologist involved in the research, stated that he and his team had collaborated with the FDA on data review and expressed little surprise at the agency’s decision. “The medicines have really been profoundly beneficial to a large number of people,” he said, emphasizing that he does not discourage patients from taking them.

Novo Nordisk released a statement acknowledging the potential impact of NAION on patients and families, while maintaining that the data do not establish a direct cause-and-effect relationship. Eli Lilly, the manufacturer of Zepbound and Mounjaro, also stated they are evaluating the FDA update and prioritize patient safety.

An FDA analysis of over 125 clinical trials revealed that the condition occurred in approximately 6 out of 100,000 patients taking GLP-1 drugs for at least a year, compared to less than 4 per 100,000 for those taking placebos or other glucose-lowering medications. Symptoms include blurred vision, blind spots, and distorted colors. The FDA advises individuals experiencing these symptoms to seek immediate medical attention.

Dr. Rizzo noted that vision loss from NAION is often irreversible and can worsen even after stopping medication. He also cautioned that the severity of vision loss can differ between eyes.