Health Canada approves weight-loss drug Zepbound for sleep apnea

Health Canada has approved Zepbound, a weight-loss drug, for treating obstructive sleep apnea in adults with obesity—the first and only GLP-1 medication approved for the condition in Canada.

The authorization, granted on June 11, marks a significant expansion of the drug's use beyond weight loss alone. Sleep apnea causes people to stop breathing temporarily because their upper airway is blocked—either from relaxed throat muscles or excess fatty tissue around the airway. The condition causes daytime sleepiness and carries risks including high blood pressure, heart attacks, and strokes.

The active ingredient in Zepbound is tirzepatide, which acts on both GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide) hormone receptors to reduce appetite and drive weight loss. Eli Lilly's tirzepatide medications, including Zepbound and diabetes drug Mounjaro, compete with Novo Nordisk's semaglutide drugs Ozempic and Wegovy.

Health Canada's approval follows Phase 3 clinical trials with patients who had both obesity and sleep apnea. The studies found that sleep apnea patients on tirzepatide who weren't using a CPAP machine had 25 fewer breathing interruptions per hour compared to five fewer disruptions among those taking a placebo. Among patients already using a CPAP machine, researchers found 29 fewer breathing interruptions per hour on tirzepatide versus six on placebo.

Dr. Mandeep Singh, a clinician investigator in sleep science at University Health Network in Toronto, said the reduction is clinically meaningful. "A reduction of 25–29 events per hour would represent a meaningful change, potentially shifting someone from severe into a lower severity category depending on where they started," he said. "I think that's a welcome step towards offering another option for patients who have obstructive sleep apnea."

Health Canada spokesperson Marie-Pier Burelle cautioned that tirzepatide is not an immediate replacement for CPAP—the first-line therapy for moderate to severe sleep apnea. "Patients taking Zepbound should not stop using their CPAP machine without a doctor's guidance," she said. The drug should be injected once a week and used alongside a reduced-calorie diet and increased physical activity in adults with a body-mass index of 30 kg/m² or higher.