Retatrutide Sleep Apnea Results: What the NEJM Trials Showed

The Headline Number

On October 20, 2026, the New England Journal of Medicine published two Phase 3 trials of retatrutide in obstructive sleep apnea (OSA), called TRIUMPH-1-OSA and TRIUMPH-2-OSA. The headline from the people without diabetes: at the 9 mg dose, the apnea-hypopnea index (AHI, the count of breathing interruptions per hour of sleep) fell by an average of 34.3 events per hour. Placebo fell by 9.9.

That is a placebo-adjusted drop of 24.4 events per hour. For context, the participants started at an average AHI of 58.6, which is severe by any definition. This is not a small tweak to a sleep chart. It is a big, measured change in how often people stop breathing at night.

And yes, retatrutide is still investigational. No approval anywhere. Hold that thought, because the timeline is the other half of this story.

What the Two Trials Actually Were

Both trials were double-blind and placebo-controlled, and both ran 80 weeks. Adults had moderate-to-severe OSA and a BMI of at least 27. Participants got weekly subcutaneous retatrutide at 4 mg, 9 mg or 12 mg, or placebo. Those are the trial doses, not a recommendation for anyone.

Here is how the groups split:

That is 691 people across the two studies. The primary endpoint was the change in AHI at week 80.

The Results, Trial by Trial

TRIUMPH-1-OSA (no diabetes), change in AHI at 80 weeks:

• 4 mg: down 22.9 events per hour (13.0 better than placebo)
• 9 mg: down 34.3 events per hour (24.4 better than placebo)
• 12 mg: down 31.7 events per hour (21.9 better than placebo)
• Placebo: down 9.9 events per hour

TRIUMPH-2-OSA (type 2 diabetes):

• 9 mg: down 24.7 events per hour, versus 10.3 for placebo (14.4 better)
• 12 mg: down 25.4 events per hour (15.1 better than placebo)

Both of the higher doses beat placebo with P<0.001. Notice the diabetes group improved less on AHI, and weight loss on retatrutide was also smaller: 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.

More than half of the people on 9 mg or 12 mg hit at least a 50% reduction in AHI. And roughly 39% to 52% of retatrutide patients reached OSA remission or mild disease without excessive daytime sleepiness. On placebo it was roughly 12% to 24%. Retatrutide also reduced sleep apnea-specific hypoxic burden, a measure tied to cardiovascular risk.

How This Fits With Earlier Retatrutide News

If these numbers feel familiar, part of the story was previewed. In June, Lilly presented TRIUMPH-1 data at the American Diabetes Association Scientific Sessions, including an OSA sub-study where retatrutide cut AHI by up to 36.1 events per hour, a 60.6% reduction from a baseline of 58.6. The NEJM paper is the full, peer-reviewed version, with the placebo comparisons and confidence intervals attached. We covered the weight-loss side in our TRIUMPH-1 breakdown.

One update to that earlier coverage: Lilly now says it plans to submit a Biologics License Application to the FDA in the first quarter of 2027, after finishing its manufacturing data package. The company has described the data as supporting submissions for obesity, knee osteoarthritis pain and obstructive sleep apnea. Plans change, so treat that date as a company target and not a promise.

Why Sleep Apnea Is the Interesting Part

Obesity trials get the headlines. Sleep apnea is where a weight-loss molecule starts looking like a real disease treatment. Here the drug moved a sleep measurement and a hypoxic burden measure, not just the scale.

A drug that cuts the AHI by more than half in a large share of patients, with remission or mild disease in roughly four in ten to half of them, changes the conversation. The honest caveat is that some of that effect likely comes through weight loss. These trials do not tell us how much is direct and how much is simply losing 15% to 20% of body weight.

The Side Effects Are the Usual Suspects

Gastrointestinal effects were the most common adverse events: diarrhea, nausea, constipation and dyspepsia. They were described as generally mild to moderate, and the safety profile was consistent with other incretin-based therapies. That is reassuring on its face, but the sources we could reach did not give exact adverse event rates or dropout numbers. Those details matter, and they are in the full paper. Read them before forming a strong opinion.

The Part That Still Stings

Here is the frustrating bit. A molecule with two big Phase 3 sleep apnea trials, positive results in a top journal, and a filing planned for early 2027 is still, today, not something a doctor can prescribe. Regulators move on their own clock, and the research community has been watching this triple-agonist (GLP-1, GIP and glucagon receptors) mature since the early days.

That gap between "the trial worked" and "you can get it" is exactly why the research peptide community pays such close attention to the primary literature. Reading the actual numbers yourself, instead of waiting for a press cycle to boil them down, is the whole point. Compare it side by side with tirzepatide and semaglutide using our comparison tool, and browse the full peptide database for the underlying data.

What To Watch Next

• The full NEJM paper, especially the adverse event tables and discontinuation rates.
• Lilly's planned FDA submission in early 2027 and whether OSA is included in the first filing.
• Whether anyone separates the weight-loss effect from a direct effect on breathing.
• Head-to-head data against tirzepatide in OSA populations.

This article is educational content, not medical advice. Retatrutide is investigational and not approved for any use. Talk to a licensed clinician about sleep apnea.

Sources

• Retatrutide Cuts Sleep Apnea Events in Phase III Trials (EMJ Reviews)
• Retatrutide Cuts Obstructive Sleep Apnea Severity in Patients With and Without Type 2 Diabetes (Physicians Weekly)
• Study: Retatrutide Decreases AHI in Adults With Sleep Apnea (HME News)
• Lilly: Retatrutide Reduces OSA Severity in Phase 3 Trial (Sleep Review)
• Retatrutide Meets Phase 3 Weight Loss Endpoints in 2 Obesity Trials (HCPLive)
• Eli Lilly's Retatrutide Delivers Major Weight Loss Results in Two Late-Stage Obesity Trials (Indian Pharma Post)