In short:
- In two new phase 3 studies, retatrutide significantly reduced the number of breathing cessations per hour in people with moderate to severe sleep apnea and overweight, clearly more than a placebo.
- The studies, TRIUMPH-1-OSA and TRIUMPH-2-OSA, were published on October 21, 2026, in The New England Journal of Medicine.
- Participants lost an average of 12 to 22% of their weight over 80 weeks. This weight loss likely explains a large part of the effect.
- Retatrutide has not yet been approved in the Netherlands and Europe and is only available within clinical research.
What is sleep apnea?
In obstructive sleep apnea, the upper airways repeatedly close briefly during sleep. Your breathing then stops briefly or becomes very shallow, after which your body partially awakens you to resume breathing. This can happen dozens of times per hour, often without you noticing. You wake up tired, are sleepy during the day, and in the long term, have a higher risk of high blood pressure and cardiovascular disease.
Doctors measure severity with the apnea-hypopnea index (AHI): the number of breathing cessations and shallow breathing events per hour of sleep. 15 to 30 per hour is considered moderate sleep apnea; 30 or more is severe sleep apnea.
Overweight is one of the main causes. Extra fat around the neck and abdomen puts pressure on the airways. Therefore, weight loss is an important part of the treatment, in addition to, for example, a CPAP device that blows air into your airways at night.
What is retatrutide?
Retatrutide is a new weight-loss medication from Eli Lilly that you inject once a week. It acts on three hormone receptors simultaneously: GLP-1, GIP, and glucagon. This reduces appetite, makes you feel full faster, and potentially helps your body burn more energy. Read more about the mechanism of action, dosage, and availability on our page about retatrutide.
How were the studies designed?
Researchers led by Ronald Grunstein from the Woolcock Institute in Australia conducted two studies simultaneously. All participants were adults with moderate to severe sleep apnea and a BMI of 27 or higher.
- TRIUMPH-1-OSA: 243 participants without diabetes.
- TRIUMPH-2-OSA: 448 participants with type 2 diabetes.
Participants received a weekly injection of 4, 9, or 12 mg retatrutide or a placebo for 80 weeks. No one knew which treatment they received. The primary outcome was how much the AHI decreased.
What were the results?
Without diabetes (TRIUMPH-1-OSA) With 9 mg retatrutide, the AHI decreased by an average of 34.3 breathing cessations per hour, and with 12 mg, by 31.7. In the placebo group, this was 9.9. The difference compared to placebo was thus approximately 22 to 24 breathing cessations per hour.
With type 2 diabetes (TRIUMPH-2-OSA) With 9 mg, the AHI decreased by an average of 24.7, and with 12 mg, by 25.4 breathing cessations per hour, compared to 10.3 with placebo. The difference compared to placebo here was approximately 14 to 15 breathing cessations per hour.
Weight loss Without diabetes, participants lost 12.5 to 22.2% of their body weight, depending on the dose, compared to 4.8% with placebo. With diabetes, this was 12.1 to 18.5%, compared to 5.6% with placebo.
People with type 2 diabetes usually lose somewhat less weight with these types of medications. This is also reflected here in a slightly smaller decrease in AHI.
Is the effect due to weight loss?
Probably largely so. The researchers themselves state that the significant weight loss likely plays an important role in the improvement of sleep apnea. Further research is needed to determine whether retatrutide also has its own effect on the airways or breathing.
What side effects occurred?
The most commonly reported side effects were gastrointestinal complaints, such as nausea, diarrhea, vomiting, and constipation. This is consistent with what we know from similar drugs such as tirzepatide and semaglutide. These symptoms primarily occur at the beginning and when increasing the dose. Long-term safety is not yet sufficiently known.
What does this mean for you?
These studies show that retatrutide could become an option in the future for people with overweight and sleep apnea. However, the medicine has not yet been approved by the European Medicines Agency (EMA) and is not available in the Netherlands outside of clinical research. Therefore, be cautious with online offers of retatrutide: these are not approved or controlled products.
Do you have sleep apnea and overweight? Never stop your CPAP or other treatment on your own. Discuss with your doctor what options are currently available for weight loss, such as a lifestyle program or an approved weight-loss medication. Do you want to know what medical weight loss can mean for you? Make an appointment for a free consultation at The Body Clinic.
This article provides general information and does not replace personal medical advice.
