Patients taking a commonly used diabetes and weight-loss drug suffered a higher rate of suicidal thoughts, a new study has suggested.
It adds to a wider debate about the drug and its safety.
The study, published on Tuesday in the Jama Network Open linked to the American Medical Association, is the first to mine the World Health Organisation’s (WHO) database of suspected side effects for reports of suicidal thinking in patients who have taken the drugs.
It found a bigger proportion of such reports from patients who had taken semaglutide, the drug that Novo Nordisk markets as Ozempic for diabetes and Wegovy for weight loss, than from those who took other medicines.
The study was carefully conducted and should lead physicians to be more cautious about prescribing semaglutide to people with a history of depression or suicide attempts, Francesco Salvo, a pharmacologist at the University of Bordeaux, wrote in an editorial published alongside the results.
Other doctors called the evidence in the paper weak and inconclusive.
“It has major limitations,” said Stephen Evans, emeritus professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine.
Spontaneous reports from patients like those in the WHO database “are very subject to bias, including effects of media reporting,” Prof Evans said.
WHO’s database is known to lack important information that would put the results in perspective, such as how long patients had been treated, the authors acknowledged.
The data might have been biased because it relied on self-reporting from patients and their doctors, they said.
The US Food and Drug Administration said this year that a preliminary evaluation did not find evidence that use of drugs like Ozempic and Wegovy causes suicidal thoughts or actions.
The agency has also said it cannot rule out a small risk and is continuing to investigate.
In April, the European Medicines Agency’s risk assessment committee found no added risk of suicide or self-harm for people taking the drugs.
The EMA and FDA findings line up with data from clinical trials, Novo Nordisk said.
The company said it will work with regulators to monitor the safety of the medicines, including surveillance of data from continuing studies and real-world use.
The use of weight-loss drugs such Ozempic has exploded in popularity in recent years, with Elon Musk and celebrities such as Oprah Winfrey, Whoopi Goldberg and Rebel Wilson openly discussing their use of slimming injections.
Ozempic received authorisation for use in the US in 2017 and the EU in 2018.
Its ability to help people lose large amounts of weight effortlessly and quickly soon spread on social media.
In the US, 20 million prescriptions were made for Ozempic in 2023, an increase of 5,000 per cent since 2018.
There are global shortages of the drug, leading authorities worldwide to warn users about counterfeit injection pens in circulation.