Twelve marketed drugs, including Eli Lilly’s and Novo’s weight loss mega-blockbusters, will require a label change under the new FDA update.
The FDA is requiring a labeling update for all approved GLP-1 receptor agonists, including products from Eli Lilly and Novo, to include a potential increased risk of a rare eye condition that can lead to vision loss.
The class-wide label change will involve adding a mention of non-arteritic anterior ischemic optic neuropathy (NAION), a serious eye condition that causes optic nerve swelling and can lead to blindness, often in one eye. With cases of NAION reported for all currently marketed GLP-1s, the FDA has concluded that the drug class is associated with a potentially higher risk of developing the condition and ordered all GLP-1 makers to update their labeling, according to a Monday release.
The agency listed 12 approved drugs that will have to make the change. These include Novo’s semaglutide drugs Wegovy and Ozempic and the heavy hitters in Lilly’s tirzepatide franchise, Zepbound and Mounjaro, plus the oral Foundayo.
“We see limited risk to our obesity coverage (specifically NVO/LLY) given rarity in incidence,” BMO analysts wrote in a Monday note. “The FDA’s action formalizes a previously recognized NAION safety signal, with low absolute event rates and a Warnings and Precautions update rather than a restriction on approved indications.”
The new regulatory change is based on an FDA assessment launched after a 2024 study published in JAMA Ophthalmology found an association between Novo’s semaglutide and higher risk of NAION.
The FDA performed a meta-analysis of 126 clinical trials across development programs, with 78,217 patients receiving a GLP-1 receptor agonist (RA). The agency “identified 15 probable NAION events, 10 in patients treated with GLP-1 RAs, five in patients receiving placebo, and none in patients who received other non-GLP-1 RA glucose-lowering medication.”
In other words, the analysis demonstrated a NAION incidence rate of 6.4 events per 100,000 patient-years for those treated with GLP-1s, compared to 3.8 events per 100,000 patient-years for comparators.
An FDA-run retrospective study using the agency’s real-world evidence data network examined NAION incidence among adults with type 2 diabetes taking medication and found no higher risk for NAION tied to GLP1s compared to SGLT-2 inhibitors, such as Boehringer Ingelheim and Eli Lilly’s Jardiance. However, the agency did identify an increased risk of NAION associated with GLP1s when compared to DPP-4 inhibitors, such as Merck’s Januvia.
The regulator also examined reports of NAION among GLP-1 users received through its adverse event monitoring system but said the reports were difficult to interpret because the disease’s risk factors often overlap with conditions commonly reported in patients treated with GLP-1s.
An FDA analysis of animal data failed to identify a mechanism for how GLP-1s could raise the potential risk of the eye condition.
The safety update comes as GLP-1s grow into some of the industry’s top-selling drugs. Eli Lilly’s tirzepatide brands Mounjaro and Zepbound generated a combined $36.51 billion in 2025, while Novo’s semaglutide franchise—Ozempic, Wegovy and Rybelsus—raked in $36.19 billion for the same year.
This is compared to Merck’s PD-1 blockbuster Keytruda, which has amassed more than 40 indications over the years and brought in nearly $32 billion in 2025.
