In short
On Nov. 9, 2026, Eli Lilly announced that its obesity pill orforglipron (sold in the United States as Foundayo) reduced the severity of obstructive sleep apnea in two phase 3 trials known together as ATTAIN-OSA. The results, presented at the American Heart Association Scientific Sessions in Chicago and published the same day in JAMA, cover 712 adults with overweight or obesity followed for 52 weeks. Lilly plans to ask the U.S. FDA to approve the use by the end of 2026. In Canada, the drug is not authorized: it is still on Health Canada’s list of submissions under review.
Eli Lilly said on Monday, Nov. 9, that orforglipron, a once-daily pill, met the primary endpoint of two phase 3 trials in adults with moderate-to-severe obstructive sleep apnea and obesity or overweight. According to the company, the drug reduced the number of pauses and slowdowns in breathing during sleep, as well as the drops in oxygen that come with them.
In this article
What the two trials found
The ATTAIN-OSA program (ClinicalTrials.gov NCT06649045) consisted of two independent double-blind studies comparing orforglipron with placebo over 52 weeks. According to Lilly’s release, the first study enrolled 363 people who were unable or unwilling to use positive airway pressure (PAP) therapy, and the second 349 people who were already on PAP and kept using it during the trial. All participants also received diet and physical-activity counselling.
Sleep apnea severity is measured with the apnea-hypopnea index (AHI), the number of times per hour that breathing stops or becomes shallow during sleep. At baseline, participants averaged 50.7 events per hour (without PAP) and 57.6 (with PAP), which is in the severe range.
According to the results published in JAMA, which include all randomized participants, including those who stopped treatment:
| Measure at 52 weeks (JAMA) | Orforglipron | Placebo |
|---|---|---|
| Study 1 (no PAP): change in AHI | −17.8 events/h | −4.5 events/h |
| Study 2 (on PAP): change in AHI | −17.3 events/h | −5.3 events/h |
Lilly highlights a different analysis that estimates the effect had all participants stayed on treatment as planned. By that measure, AHI fell by 21.1 events per hour (−43.8%) without PAP and by 18.3 events per hour (−27.5%) with PAP. The company says 31.5% of participants without PAP and 19.6% of those on PAP reached remission or mild disease. Hypoxic burden, a measure of how deeply and for how long oxygen levels fall, dropped by 55.9% and 45.8% respectively.
Participants on orforglipron lost an average of 11.5% (no PAP) and 11.2% (on PAP) of their body weight, versus 1.8% and 0.9% on placebo, according to the release. Lilly also reported reductions in systolic blood pressure of 8.6 and 7.3 mmHg and in C-reactive protein, a marker of inflammation.
Side effects and dropouts
Gastrointestinal events were the most common. According to the JAMA summary, they occurred in 68.0% of participants on orforglipron versus 37.4% on placebo in the first study, and in 70.6% versus 36.6% in the second. Lilly lists mainly nausea, diarrhea, constipation, dyspepsia and vomiting, which it says were “generally mild to moderate in severity.”
Discontinuations due to adverse events were more frequent on treatment: 12.2% versus 3.8% without PAP and 6.8% versus 0.6% with PAP, according to the company. The JAMA summary notes that these events “may affect treatment decisions.”
What researchers said
“We know there’s a two-way relationship between sleep and cardiovascular health, and the repeated drops in oxygen that happen with obstructive sleep apnea can strain blood pressure and the heart over time,” Dr. Vaishnavi Kundel, associate professor of medicine at the Icahn School of Medicine at Mount Sinai, said in Lilly’s release.
Dr. Thomas Seck, Lilly’s senior vice-president of product development for cardiometabolic health, said in the same release that “OSA is one of the most serious complications of obesity and is closely linked to cardiovascular disease.”
The research was funded by Eli Lilly, as the JAMA summary states.
Background
Obstructive sleep apnea happens when the airway repeatedly collapses during the night. Lilly puts the number of affected adults worldwide at 936 million, citing a 2019 analysis in The Lancet Respiratory Medicine. The standard treatment remains PAP, a machine that delivers pressurized air through a mask.
Orforglipron is a GLP-1 receptor agonist like semaglutide (Ozempic, Wegovy), but it is a small molecule rather than a peptide, which lets it be taken as a pill without food or water restrictions, according to Lilly. The FDA approved it on April 1, 2026, for weight management in adults. In the U.S., the same company’s injectable Zepbound (tirzepatide) is already approved for moderate-to-severe sleep apnea in adults with obesity.
What it means in Canada
For now, nothing concrete for patients. Orforglipron has no marketing authorization in Canada. According to Health Canada’s list of new drug submissions under review (current as of Sept. 30, 2026), Eli Lilly Canada’s submission for orforglipron was accepted into review in January 2026. That submission covers the use already approved in the U.S., not sleep apnea.
Lilly says it plans to submit the sleep apnea indication to the FDA by the end of 2026, with “other global submissions to follow,” without giving a timeline for Canada. According to ClinicalTrials.gov, none of the ATTAIN-OSA sites were in Canada: the trial ran in nine countries, including the United States, Mexico, Germany and Japan.
Canadians with sleep apnea who are curious about these drugs should talk to their doctor. Obesity medications already authorized in Canada, including semaglutide and its generic versions, are prescribed for weight management.
What we don’t know yet
- Whether the benefits last beyond 52 weeks, and what happens when treatment stops
- Whether the improvement in apnea comes mostly from weight loss or from another effect of the drug
- Whether the drop in blood pressure translates into fewer cardiovascular events (a separate trial, ATTAIN-Hypertension, is under way, according to Lilly)
- How much of the weight lost is muscle, an important question with all GLP-1 drugs (see our article on muscle loss)
- When, or whether, Health Canada will authorize orforglipron
Key point
This article reports clinical trial results. It is not medical advice. Do not change a sleep apnea treatment such as PAP without talking to a health professional.
Frequently asked questions
What is the ATTAIN-OSA trial?
It is a Lilly phase 3 program made up of two placebo-controlled trials, run over 52 weeks in 712 adults with moderate-to-severe obstructive sleep apnea and obesity or overweight, with or without PAP therapy.
Does orforglipron cure sleep apnea?
No. According to Lilly, 31.5% of participants without PAP reached remission or mild disease after one year, which means most still had moderate or severe apnea.
Is orforglipron (Foundayo) available in Canada?
No. Health Canada is reviewing an Eli Lilly Canada submission accepted in January 2026, but no authorization has been announced.
Can I stop using my CPAP if I take a GLP-1 drug?
These trials do not support that conclusion. In the second study, participants kept using their PAP. Any decision should be made with a doctor.
What side effects were seen?
Mainly gastrointestinal effects (nausea, diarrhea, constipation, vomiting), in about 70% of participants on orforglipron versus about 37% on placebo, according to JAMA.
Sources
- Eli Lilly. Lilly’s Foundayo (orforglipron) significantly reduced obstructive sleep apnea severity, Nov. 9, 2026 (PR Newswire)
- Malhotra A et al. Orforglipron for Obstructive Sleep Apnea: Research Summary. JAMA, Nov. 9, 2026
- ClinicalTrials.gov. ATTAIN-OSA, NCT06649045
- Health Canada. New drug submissions under review (list current as of Sept. 30, 2026)
This article is for information only and does not replace advice from a health professional. Talk to your doctor, pharmacist or a registered dietitian before changing your treatment, diet or exercise.
