While Novo is struggling to keep up with demand for its obesity drugs, U.S. rival Eli Lilly sees supply restraints easing.

A pair of late-stage trials found that Eli Lilly’s experimental once-weekly insulin can lower blood sugar as effectively as widely used daily insulins, the drugmaker said Thursday, intensifying the company’s race with Novo Nordisk to develop longer-acting insulins.

Novo Nordisk said the shortage of lower strengths of its diabetes drug Ozempic has deteriorated, with intermittent shortages for all strengths expected into the final quarter of 2024 due to increased demand and along with capacity constraints at some of its manufacturing sites.

Today, patients on insulin receive injections daily, or even more often, but both companies are working to change that.

Novo Nordisk 's ( NVO 1.19%) GLP-1 medicines, Ozempic and Wegovy, are bestsellers and household names. Whereas Ozempic is indicated for type 2 diabetes, Wegovy is prescribed for weight loss in the context of obesity. But, if some new information holds true, the company could soon see its presence in both of those markets take a hit.

Intermittent shortages of diabetes drug Ozempic in the European Union that are expected to continue into the final quarter of 2024 because of strong demand will not affect all member states, the Danish drugmaker Novo Nordisk said.

Novo Nordisk ( NVO) has said in a note published by the European Medicines Agency that the supply shortage of its diabetes drug Ozempic (semaglutide) will continue into the fourth quarter of 2024.

However, various potential headwinds have popped up that could disrupt Ozempic's progress. One of them is competition. Novo Nordisk's longtime foe in the diabetes market, Eli Lilly, developed Mounjaro, a diabetes medicine whose sales are growing incredibly fast.