The European Medicines Agency (EMA) is investigating Novo Nordisk’s (NOVOb.CO) diabetes drug Ozempic and weight-loss treatment Saxenda after Iceland’s health regulator flagged three cases of patients thinking about suicide or self-harm.

Shares of the Danish drugmaker fell 1% on Monday following the news.

An EMA safety committee is looking into adverse events raised by the Icelandic Medicines Agency, including two cases of suicidal thoughts in those who used Ozempic, which contains the active ingredient semaglutide, and Saxenda, the regulator said.

Another patient on Saxenda, Novo’s earlier and less effective weight-loss drug that contains a different active ingredient, reported thoughts of self-injury, the agency said.

Novo Nordisk said patient safety was top priority and it treated all reports about adverse events very seriously.

Safety data did not show any “causal association” between the suicidal or self-harming thoughts and the drugs, it added in a statement.

The EMA’s investigation centers on medicines that contain either semaglutide or liraglutide. Novo’s obesity treatment Wegovy, for which demand has surged in the United States, contains semaglutide, while Saxenda contains liraglutide.

The review has been announced weeks after the regulator raised a thyroid cancer safety signal, a means to monitor potentially adverse effects, on several of Novo’s products that contain semaglutide.

Suicidal thoughts are not listed as a side effect in the EU product information of the treatments.

In the United States, however, instructions for Wegovy recommend that patients are monitored for suicidal thoughts or behaviour.

According to the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) Public Dashboard, there have been at least 60 reports of suicidal ideation since 2018 from patients on semaglutide or their health care providers.

In addition, FAERS has received at least 70 such reports from users of liraglutide or their health care providers since 2010.

Information in FAERS reports has not been verified and the existence of a report is not proof of causation, the FDA says. The agency did not immediately respond when asked whether it plans to study any link.

Side effects have hobbled several previous attempts by the drug industry to develop lucrative weight-loss drugs.

Sanofi’s (SASY.PA) Acomplia, which never won a U.S. approval, was withdrawn in Europe in 2008 after being linked to suicidal thoughts.

Acomplia was designed to modify parts of the nervous system that regulate appetite. New weight-loss drugs such as Wegovy, however, regulate appetite by mimicking a gut hormone, and not directly interfering with brain chemistry.

The EMA said on Monday it would consider whether the review should be extended to other medicines of the same class known as GLP-1 receptor agonists.

Penny Ward, a visiting professor in pharmaceutical medicine at Kings College in London and an expert on drug safety monitoring in the EU, said it was unclear why the very small number of reports triggered the EMA’s review, but that it could result in a serious action such as one of the products being withdrawn from the market.

“It’s more likely that this results in a change to the labelling, so that prescribers are made aware of this possible effect so they can warn patients and look out for people who may be particularly susceptible to this kind of problem,” Ward said.

Reporting by Bhanvi Satija in Bengaluru, Ludwig Burger in Frankfurt, Maggie Fick in London and Michael Erman in New York; Editing by Savio D’Souza, Nivedita Bhattacharjee, Sriraj Kalluvila and Barbara Lewis