Health regulators in Europe will investigate whether Ozempic and other weifht loss drugs cause blindness.
Several studies have now linked the shots to a condition that blocks blood flow to the nerves of the eye, causing vision loss.
Harvard doctors began investigating NovoNordisk's blockbuster drug, which is officially approved for diabetes treatment, in 2023, after three patients taking the drug were diagnosed with the condition in one week.
Their findings, published in July, warned that Ozempic may be linked to a two fold increase in cases of non-arteritic anterior ischemic optic neuropathy (NAION).
Then, earlier this month two studies out of Denmark, where Ozempic's maker is based, found a similar connection.
That prompted the Danish government to investigate, and initiate a request with the EU. They said the new studies: 'Reinforce this suspicion and may hold new important information that should be assessed.'
NAION occurs when blood flow gets cut off to the nerve that connects the eye to the brain, interrupting the connection and making someone blind.
It's unclear how semaglutide may raise these risks, because it mainly works to imitate hormones that control hunger.
Ozempic is approved only as a treatment for diabetes, but some patients get it prescribed off label for weight loss. Wegovy, which has the same active ingredient at different doses, is approved for weight loss. The drug works to mimic hormones that control hunger and digestion rates
Since their approval and mass circulation, patients have reported a number of unexpected side effects linked to the various weight loss drugs.
Black box warnings for the Ozempic include that it may increase the risk of developing thyroid tumors. The label also warns about the risk of developing stomach paralysis which can lead to nausea, vomiting and malnutrition.
Other individuals have reported developing problems with suicidal thoughts, sexual dysfunction and hair loss as a result of the drug.
Roughly 6 percent of Americans who are currently using some form of the drug - representing more than 15million people.
NAION can occur naturally, because of things like old age, high blood pressure or blood vessel problems, or because of habits like smoking. It affects an estimated 6000 Americans each year, according to UC Davis Health.
Doctors disagree on why this happens, but sugget that it could be that damage to blood vessels, or clots within these pathways, may lead to the loss of blood flow to this crucial region.
Two separate investigations at the University of Southern Denmark found that people who had been taking semaglutide had an increased risk of developing NAION.
The first study, which looked at 424,152 Danes with diabetes and found that Ozempic doubles the risk of NAION, has been accepted for publication in a journal.
The second study, which compared diabetics who use Ozempic with diabetics who use other drugs to manage their condition, is undergoing the peer review process.
It found that: 'Semaglutide is associated to an increased risk of NAION, but also that the excess absolute risk is low.'
Though neither has been formally published, the Danish scientists thought their preliminary findings were compelling enough to notify health officials.
The Danish Medicines Agency, which had already been tracking NAION cases linked to the injections, asked the EU's Pharmacovigilance Risk Assessment Committee to investigate the link.
It is unclear if the EU's independent drug regulator has agreed to start this investigation.
The Danish findings build on blockbuster studies performed in America that were released this summer.
In the Harvard study, which was published in the Journal of the American Medical Association Opthamology, the researchers looked at data from over 16,000 patients who were using semaglutide, the active ingredient in Ozempic and Wegovy.
Over three years, 8.9 percent of people with diabetes who were taking the drug developed NAION, compared with 1.8 percent of people who were taking other drugs.
Real Housewives of New Jersey star Dolores Catania admitted to using Ozempic to lose weight for the six weeks ahead of the RHNJ reunion
Though this trend was clear in the study, the doctors cautioned that it can't be concluded from their findings that Ozempic caused the vision loss.
Study author Joseph Rizzo, a professor of ophthalmology at Harvard Medical School, said: 'Our findings should be viewed as being significant but tentative, as future studies are needed to examine these questions in a much larger and more diverse population.'
Dr Rizzo added: 'It is important to appreciate, however, that the increased risk relates to a disorder that is relatively uncommon.'
Likewise, NovoNordisk, who manufactures both Ozempic and Wegovy, issued statements that claim this link is unproven and rare.
In response to this move from Danish authorities, a NovoNordisk spokesperson said: 'After a thorough evaluation of the studies from the University of Southern Denmark and Novo Nordisk’s internal safety assessment, Novo Nordisk is of the opinion that the benefit-risk profile of semaglutide remains unchanged'
It's not clear if US regulators are looking into a similar . Dailymail.com has contacted the FDA for comment on whether they'll also be investigating.