Retatrutide and Sleep Apnea: What a Big New Trial Found
Research Brief | Dr. Ethan Lazarus, MD | Clinical Nutrition Center | October 27, 2026
A weight loss drug may also help with sleep apnea. Two large trials published in the New England Journal of Medicine on October 21, 2026 point that way.
The drug is retatrutide, and it is still investigational: not FDA approved, and not something you can get on a prescription yet.
What the trials found
Two trials, TRIUMPH-1-OSA and TRIUMPH-2-OSA, enrolled 691 adults with obesity and moderate to severe sleep apnea. One group had type 2 diabetes, the other did not.
To measure sleep apnea, doctors count how many times per hour you stop breathing or breathe shallowly during sleep, called the AHI. Severe sleep apnea starts at 30 events per hour, and these patients averaged 55 to 60.
On the middle dose, 9 mg a week, the drug cut breathing events by about 34 an hour without diabetes and about 25 an hour with diabetes. People on placebo improved by about 10.
About half the people taking retatrutide ended up with mild sleep apnea or none at all, without feeling excessively sleepy during the day. On placebo, one in eight got there.
Weight loss came alongside it: 22% of body weight without diabetes, 18% with diabetes, against about 5% on placebo.
The oxygen side of it
Repeated drops in oxygen at night put stress on the heart. Time spent with low oxygen dropped by about three quarters without diabetes and two thirds with diabetes.
Here is where I want to be careful. Low oxygen at night is linked to heart disease, but we do not yet know this drug prevents heart attacks. The researchers said longer studies are needed.
Side effects
Stomach and bowel problems. Diarrhea hit 30 to 44% of people on retatrutide versus 15% on placebo, nausea 20 to 27% versus 10%, and constipation 16 to 23% versus 10%. Most were mild to moderate, and hit hardest during dose increases.
Serious side effects hit 8% of people on the drug and 10% on placebo. One person on the 9 mg dose died from gastrointestinal complications. Three people on placebo died. No cases of thyroid cancer and no drug-induced liver injury.
Nobody should read a side effect section without the numbers.
What about CPAP
The trials included people who could not use CPAP or chose not to, and people on it for months.
For people who reached mild sleep apnea or none on retatrutide and were not excessively sleepy during the day, CPAP may no longer be needed. Your sleep specialist decides.
Bottom line
This is the strongest data anyone has on a drug treating sleep apnea directly, and it held with or without diabetes. But retatrutide is not approved. Eli Lilly plans to file in early 2027.
If you have sleep apnea and want to treat it, do not wait for this drug. Weight loss helps. CPAP helps. Both are available today.