Weekly Injection Cuts Sleep Apnea Episodes by Up to 34 an Hour

Retatrutide acts on three hormone receptors involved in appetite, blood sugar and the way the body uses energy.

How big were the changes?

The two trials enrolled 243 adults without type 2 diabetes and 448 with it. Everyone had moderate to severe sleep apnea and a body mass index of at least 27.

Participants were randomly assigned to one of three doses of retatrutide or an inactive injection once a week. Neither they nor the study teams knew who got which treatment during the trial. Researchers then measured how often breathing stopped or slowed during each hour of sleep.

After 80 weeks, the results stacked up like this:

• People without diabetes on the two higher doses had about 32 to 34 fewer breathing interruptions an hour; the inactive-injection group had about 10 fewer.
• People with diabetes on the higher doses saw roughly 25 fewer events an hour, versus about 10 in the comparison group.
• Across both trials, 39% to 52% of people on higher doses improved to the point of having no sleep apnea or mild sleep apnea without excessive daytime sleepiness. About 13% on inactive injections reached that threshold.
• Weight loss ranged from about 12% to 22% across doses in the trial without diabetes, and 12% to 19% in the diabetes trial. Comparison groups lost about 5% to 6%.

The weight came down and the breathing improved. Both happened together, in both trials.

What are the caveats?

Digestive problems were the most common side effects.

Eli Lilly funded both trials, which compared the drug only with an inactive injection. They did not directly test it against established treatments such as positive airway pressure, the device-based therapy that keeps the airway open during sleep.

The results also apply specifically to the adults enrolled in the trials. Longer follow-up could clarify how much of the improvement lasts, and additional studies could determine how the drug might fit alongside existing care for sleep apnea.

Still, the findings suggest a possible new treatment option for adults with overweight or obesity who also live with sleep apnea. Related research is already exploring who benefits most from weight-loss medicines for this condition.

The bottom line: an experimental weekly injection sharply reduced breathing interruptions in two large trials, but it hasn't yet been tested head-to-head against standard therapy.