The injectable drug, produced by Novo Nordisk, was approved around six years ago because it successfully lowered blood sugar levels almost immediately. But it came with serious risks: the US’s drug regulator, the Food and Drug Administration (FDA), warned that the drug increased the risk of thyroid cancer. Common side effects, such as nausea, vomiting and diarrhea, have also made the drug difficult to take.

And now researchers from the Karolinksa Institute in Sweden have also discovered that any benefits are short-lived; after 250 days, or 35 weeks, the drug impairs the body’s already-compromised ability to produce insulin.

Their research has thus far been restricted to tests on laboratory mice, but they say the evidence is sufficient for doctors to be aware of the risk and monitor the health of their patients.

Liraglutide is a blood-sugar suppressing GLP-1 analogue.