| Trial results
The New England Journal of Medicine published two placebo-controlled trials of once-weekly retatrutide in adults with moderate-to-severe obstructive sleep apnea and a body mass index of at least 27. TRIUMPH-1-OSA had 243 people without type 2 diabetes. TRIUMPH-2-OSA had 448 people with type 2 diabetes. At 80 weeks, the average number of breathing interruptions per hour of sleep (the AHI) fell by 9.9 on placebo in the first trial and by 22.9, 34.3 and 31.7 on the 4 mg, 9 mg and 12 mg doses. In the second trial it fell by 10.3 on placebo and by 19.2, 24.7 and 25.4.
Average weight loss was 12.5% to 22.2% in the first trial and 12.1% to 18.5% in the second, versus 4.8% and 5.6% on placebo. The most common side effects were stomach and gut problems.
Worth knowing: The AHI counts breathing events. The abstract does not say how many people no longer had sleep apnea afterward. Lilly paid for the trials, and retatrutide is not approved for any use. Lilly has said it plans to file with the FDA in the first quarter of 2027.
Related: Sleep apnea and weight-loss medicines: what the trials show | Medicine library
Source: Grunstein RR, et al. N Engl J Med. Published October 20, 2026. Presented at the 28th Congress of the European Sleep Research Society Journal article.