Does retatrutide treat obstructive sleep apnea?

The short answer

Two phase 3 trials published in the New England Journal of Medicine (reported in October 2026) found that retatrutide, Eli Lilly's investigational once-weekly triple agonist, substantially reduced sleep apnea severity in adults with moderate-to-severe obstructive sleep apnea (OSA) and overweight or obesity. In people without type 2 diabetes, the 9 mg dose cut breathing events by 34.3 per hour versus 9.9 with placebo after 80 weeks. In people with type 2 diabetes, the effect was smaller but still large. Retatrutide is not approved for anything yet, and these results do not make it available to buy.

Evidence tier: Tier 1–2 — two randomized, double-blind, placebo-controlled phase 3 trials, published in a peer-reviewed journal. Long-term outcomes and an FDA review are still ahead. This is education, not medical advice.

The key points:

• TRIUMPH-1-OSA (243 adults without type 2 diabetes): AHI fell by 22.9, 34.3 and 31.7 events per hour on 4, 9 and 12 mg, versus 9.9 on placebo
• TRIUMPH-2-OSA (448 adults with type 2 diabetes): AHI fell by 24.7 and 25.4 events per hour on 9 and 12 mg, versus 10.3 on placebo
• Weight loss was large — 12.5–22.2% of body weight without diabetes and 12.1–18.5% with diabetes, versus about 5% on placebo
• Side effects were mostly gastrointestinal, as with other drugs in this class
• It is still investigational — no FDA approval, and no legal way to get it outside a trial

What the trials tested

Evidence tier: 1–2 — randomized controlled trials.

Both trials enrolled adults with moderate-to-severe OSA and a body mass index of at least 27, and randomized them to weekly injections of retatrutide 4 mg, 9 mg or 12 mg, or placebo, for 80 weeks (EMJ, Oct 2026). TRIUMPH-1-OSA ran as an OSA "basket" inside the larger TRIUMPH-1 obesity trial and included 243 people without type 2 diabetes; TRIUMPH-2-OSA included 448 people with type 2 diabetes. The main outcome was the change in the apnea–hypopnea index (AHI), the number of times per hour breathing stops or becomes shallow during sleep. The results were published in the NEJM by Grunstein and colleagues (Grunstein 2026) and presented at the European Sleep Research Society congress.

For context on the scale: an AHI of 15–30 events per hour is moderate OSA and 30 or more is severe, so a drop of 25–35 events per hour can move someone a full severity category or more.

The results

Evidence tier: 1–2 — primary-endpoint results from both trials.

Without type 2 diabetes (TRIUMPH-1-OSA). AHI fell by 22.9 events per hour on 4 mg, 34.3 on 9 mg and 31.7 on 12 mg, compared with 9.9 on placebo. The placebo-adjusted differences were 24.4 events per hour for 9 mg and 21.9 for 12 mg, both highly significant (HCPLive, Sep 2026; EMJ). Participants lost 12.5–22.2% of their body weight depending on dose, versus 4.8% on placebo.

With type 2 diabetes (TRIUMPH-2-OSA). AHI fell by 24.7 events per hour on 9 mg and 25.4 on 12 mg, compared with 10.3 on placebo. Weight loss was 12.1–18.5% versus 5.6% on placebo (EMJ). Smaller weight loss in people with diabetes is a familiar pattern across the GLP-1 class, and the smaller AHI change tracks with it.

Two things are worth noticing. The 9 mg dose did at least as well as 12 mg on sleep apnea in the non-diabetic trial, so "highest dose" did not mean "best result" here. And placebo groups also improved by about 10 events per hour, which is why the placebo-adjusted numbers matter more than the headline drops.

Is it the weight loss?

Evidence tier: 3 — interpretation; the trials were not designed to separate the two.

Excess weight around the neck and upper airway is the main modifiable driver of OSA, and the size of the AHI improvements tracks the size of the weight loss across doses and trials. The simplest reading is that most of the benefit comes from weight loss, though the published coverage we could review does not report an analysis that separates weight from any direct effect of the drug. The same question applied to tirzepatide, which reduced AHI by about 25–29 events per hour in the SURMOUNT-OSA trials (Malhotra 2024) and became the first medicine FDA-approved for OSA in adults with obesity in December 2024. Retatrutide's numbers are in the same range; there is no head-to-head trial.

Safety

Evidence tier: 2 — trial adverse-event reporting.

The most common side effects were gastrointestinal — nausea, diarrhea, constipation and vomiting — and mostly mild to moderate (Sleep Review; HCPLive). In the wider TRIUMPH-1 trial, symptoms of low blood pressure were dose-dependent and more common in people already taking blood-pressure medication. We did not find discontinuation rates for the OSA trials in the sources we could review; check the full NEJM paper for those.

Can you get retatrutide for sleep apnea?

Evidence tier: regulatory status.

No. Retatrutide is investigational and not approved by the FDA or any other regulator; outside a clinical trial there is no legitimate source (our legal-status guide). Products sold online as "retatrutide" are unregulated and Lilly has sued sellers (Lilly lawsuits). For context on timing, a Polymarket prediction market on whether the FDA approves retatrutide in 2026 was trading at about 3% in late October 2026 — a reflection of the fact that approval this year is not expected, not a forecast of whether it will eventually be approved.

If you have OSA and obesity today, the approved options are CPAP or other airway treatments, weight management, and — where appropriate — tirzepatide (Zepbound), which has the OSA indication. Talk to a sleep physician; untreated moderate-to-severe OSA carries real cardiovascular risk.

What we still don't know

• How durable the improvement is after 80 weeks, and what happens if the drug is stopped
• How many participants reached remission or mild OSA — we could not verify these figures from the sources we reviewed
• Whether benefits extend to people using CPAP, and to sleepiness and quality of life
• How retatrutide compares with tirzepatide head to head
• When Lilly will file with the FDA, and what the label will say

Related on this site

• Retatrutide deep dive: the triple agonist explained
• Retatrutide vs tirzepatide
• Retatrutide dosing: what the trials show
• Can you legally buy retatrutide?
• GLP-1 complete guide
• Our evidence-tier framework

References

• Grunstein RR, et al. 2026. Retatrutide Once Weekly for Treatment of Obstructive Sleep Apnea. N Engl J Med. doi:10.1056/NEJMoa2611477
• Jastreboff A, et al. 2026. Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity (TRIUMPH-1). N Engl J Med. doi:10.1056/NEJMoa2604169
• Malhotra A, et al. 2024. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity. N Engl J Med. PMID 38912654
• EMJ. 24 Oct 2026. Retatrutide cuts sleep apnea events in phase III trials. emjreviews.com
• HCPLive. 29 Sep 2026. Retatrutide improves weight loss, knee osteoarthritis pain, sleep apnea versus placebo. hcplive.com
• Sleep Review. 23 Jun 2026. Lilly's investigational triple agonist retatrutide reduces OSA severity in phase 3 trial. sleepreviewmag.com
• ClinicalTrials.gov: NCT05929066, NCT05929079

Limitations

This is educational content, not medical advice. We could not access the full NEJM paper; figures come from the abstract-level reporting in the cited medical news coverage, which agree on the primary results. Remission rates, discontinuation rates and subgroup analyses are not included for that reason.