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Anvisa investigates vision loss risks linked to GLP-1 weight-loss drugs
The Brazilian Health Regulatory Agency, Anvisa, is investigating 13 suspected cases of non-arteritic anterior ischemic optic neuropathy (NAION) in patients using GLP-1 receptor agonists. This rare condition involves an interruption of blood flow to the optic nerve, which can lead to sudden and potentially permanent vision loss.
The reported cases involve several medications, including Ozempic, Wegovy, Rybelsus, and Mounjaro. Specifically, 12 reports are linked to semaglutide and one to tirzepatide. Anvisa emphasizes that these are currently unconfirmed suspicions and that the use of these medications does not inherently prove a causal relationship with the eye condition.
A study published in JAMA Ophthalmology noted that patients receiving semaglutide had a four to seven times higher risk of developing NAION compared to those using other medications, though researchers noted limitations in establishing direct causality.
In response to safety concerns, Anvisa mandated in June 2025 that NAION be listed as a very rare adverse reaction on the labels of semaglutide-based products. Pharmaceutical manufacturers Novo Nordisk and Eli Lilly have stated that their internal clinical trials and ongoing safety monitoring have not identified a definitive link to the disease.
Entities
Anvisa · Eli Lilly · Mounjaro · Novo Nordisk · Ozempic
Claims
What the coverage asserts, and how many sources carry each claim.
- [● 9 SOURCES] Anvisa is investigating 13 suspected cases of non-arteritic anterior ischemic optic neuropathy (NAION). vtvnews.com.br · www.blogdojasao.com.br · clicrdc.com.br · www.tnh1.com.br · atarde.com.br · +4 more
- [● 8 SOURCES] Anvisa emphasizes that the reported cases are suspicions and do not prove a causal link between the drugs and the condition. www.blogdojasao.com.br · clicrdc.com.br · www.tnh1.com.br · atarde.com.br · noticiacapital.com.br · +3 more
- [● 4 SOURCES] The 13 suspected cases involve Ozempic (5), Wegovy (3), Wegovy FlexTouch (2), Rybelsus (2), and Mounjaro (1). clicrdc.com.br · www.tnh1.com.br · olhardigital.com.br · exame.com
- [● 3 SOURCES] Anvisa has recorded 24 total suspected cases of ischemic optic neuropathy in Brazil since 2018. vtvnews.com.br · clicrdc.com.br · olhardigital.com.br
- [● 5 SOURCES] Novo Nordisk claims internal clinical trial analyses showed no increase in disease cases associated with semaglutide. www.tnh1.com.br · atarde.com.br · noticiacapital.com.br · www.osul.com.br · exame.com
- [● 3 SOURCES] Anvisa mandated that NAION be included in the labels of semaglutide-containing medications as a very rare side effect in June 2025. vtvnews.com.br · www.blogdojasao.com.br · olhardigital.com.br
- [● 5 SOURCES] A study in JAMA Ophthalmology found a four to seven times higher risk of NAION in patients using semaglutide compared to other medications. www.blogdojasao.com.br · atarde.com.br · noticiacapital.com.br · olhardigital.com.br · www.osul.com.br
- [● 5 SOURCES] Eli Lilly states it is constantly monitoring safety data for its products, including ophthalmological events. www.tnh1.com.br · atarde.com.br · noticiacapital.com.br · www.osul.com.br · exame.com