Tirzepatide and Obstructive Sleep Apnoea

Mounjaro (tirzepatide) can substantially reduce the severity of obstructive sleep apnoea (OSA) in adults with obesity, according to the SURMOUNT-OSA trials published in 2024. The benefit comes mainly through weight loss. In the UK, Mounjaro is licensed for weight management rather than specifically for sleep apnoea at the time of writing, but OSA is one of the weight-related conditions used to prioritise NHS access. Tirzepatide is not a replacement for CPAP or sleep-service care, and decisions about treatment belong to your prescriber and sleep team.

What obstructive sleep apnoea is

Obstructive sleep apnoea is a condition in which the throat repeatedly narrows or closes during sleep, interrupting breathing. Each interruption lowers oxygen levels and briefly wakes the brain, often without the person being aware of it. The NHS describes common symptoms as loud snoring, noisy or laboured breathing, pauses in breathing noticed by a partner, waking up gasping or choking, and feeling very sleepy during the day.

Severity is usually measured by the apnoea–hypopnoea index (AHI), the average number of times per hour that breathing stops (apnoea) or becomes very shallow (hypopnoea) during sleep.

Untreated, moderate or severe OSA is linked to daytime sleepiness, poor concentration, low mood, high blood pressure, heart rhythm problems, type 2 diabetes, and an increased risk of road traffic accidents. In the UK, people diagnosed with OSA that causes excessive sleepiness may need to tell the DVLA, which your sleep service can advise on.

Why weight matters

Excess weight is the strongest modifiable risk factor for OSA. Fat deposited around the neck and upper airway narrows the space available for air, and fat around the abdomen reduces lung volume, which makes the airway more collapsible. Not everyone with OSA has obesity, and not everyone with obesity has OSA, but the two are closely linked. Weight gain tends to worsen OSA and weight loss tends to improve it.

NICE guideline NG202 on obstructive sleep apnoea (2021) recommends that people with OSA and overweight or obesity are offered support with weight management as part of their care, alongside treatments such as CPAP. NICE guideline NG246 on overweight and obesity management (2025) also lists sleep apnoea among the conditions linked to obesity.

How tirzepatide works

Tirzepatide is a once-weekly injection that activates two hormone receptors involved in appetite and blood glucose: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). It reduces appetite, increases fullness and slows stomach emptying, which together lead to eating less. Our guide to how Mounjaro works explains the science in more detail, and our Mounjaro hub brings together everything on the medicine.

There is no strong evidence that tirzepatide acts directly on the airway. Its effect on OSA appears to come mainly through weight loss, together with possible improvements in inflammation and metabolic health.

The SURMOUNT-OSA trials

Design

SURMOUNT-OSA was published in the New England Journal of Medicine in 2024. It consisted of two parallel phase 3, double-blind, placebo-controlled trials, each lasting 52 weeks. Together they enrolled 469 adults who had obesity and moderate-to-severe OSA, and who did not have diabetes.

• Trial 1 included people who were not using positive airway pressure (PAP) therapy, such as CPAP, either because they could not tolerate it or chose not to use it.
• Trial 2 included people who were using PAP therapy and planned to continue during the trial.

Participants received either the maximum tolerated dose of tirzepatide (10mg or 15mg weekly) or a placebo injection. Everyone also received lifestyle advice.

Main results

The main outcome was the change in AHI after 52 weeks.

To put this in context, participants started the trials with moderate-to-severe OSA, typically with AHI values well above 30. A reduction of 25 to 29 events per hour therefore represented around half or more of their starting severity on average.

The trials also reported that, on tirzepatide, a substantially larger proportion of participants improved to the point where their OSA was in remission or mild without daytime sleepiness, a level at which CPAP might no longer be recommended. Published summaries put this at almost half of those on tirzepatide, compared with a much smaller proportion on placebo.

Other findings

Secondary outcomes reported by the investigators included:

• reductions in oxygen desaturation burden (a measure of how much oxygen levels dropped during sleep)
• lower systolic blood pressure
• reductions in high-sensitivity C-reactive protein, a marker of inflammation
• improvements in patient-reported sleep-related symptoms and functioning

Side effects in the trials

The side effects were similar to those seen in other tirzepatide trials, mainly gastrointestinal: nausea, diarrhoea, vomiting and constipation, mostly mild to moderate and most common during dose increases. Our guide to Mounjaro side effects covers these in detail.

Regulatory status

United States

The US Food and Drug Administration approved tirzepatide, under the brand name Zepbound, for moderate-to-severe OSA in adults with obesity in December 2024, making it the first medicine approved for this use there.

Europe

The European Medicines Agency assessed an application to add OSA as a separate indication for Mounjaro. It concluded that the benefits in OSA are achieved through weight reduction and are therefore covered by the existing weight management indication, with the trial data to be included in the product information rather than as a separate indication.

United Kingdom

In the UK, Mounjaro is authorised by the MHRA for weight management (alongside diet and physical activity) and for type 2 diabetes. At the time of writing we have not been able to confirm a separate UK licensed indication for OSA. If you need the current position, check the Mounjaro SmPC on medicines.org.uk or ask your prescriber or pharmacist. Our complete guide to Mounjaro in the UK covers the licence in more detail.

In practical terms, this means that in the UK, tirzepatide is prescribed for people who meet weight management criteria. Having OSA may make treatment more clinically appropriate, but it does not by itself make someone eligible.

OSA and NHS access to Mounjaro

NICE recommended tirzepatide for managing overweight and obesity in technology appraisal TA1026 (December 2024). Because of the very large number of potentially eligible people, NHS England agreed a phased rollout in primary care.

The first cohort, from June 2025, covers people with a BMI of at least 40 who also have at least four of five specified weight-related conditions:

• obstructive sleep apnoea
• type 2 diabetes
• high blood pressure (hypertension)
• abnormal blood fats (dyslipidaemia)
• atherosclerotic cardiovascular disease

Lower BMI thresholds, usually by 2.5 kg/m², are applied for people from South Asian, Chinese, other Asian, Middle Eastern, Black African and African-Caribbean backgrounds. Later phases are expected to widen access over several years. NHS prescribing also comes with wraparound support on diet, activity and behaviour.

If you have diagnosed OSA and think you may qualify, your GP can tell you whether you meet the current criteria. Our guides to Mounjaro on the NHS and who can get weight loss injections explain eligibility further.

Tirzepatide and CPAP: how they fit together

CPAP (continuous positive airway pressure) remains the main treatment for moderate-to-severe OSA in the UK. It works immediately, every night, by using gentle air pressure to keep the airway open. NICE has recommended CPAP for moderate and severe OSA for many years.

Tirzepatide works differently. It takes months to produce weight loss, and its effect on OSA builds gradually. It also only works for as long as weight loss is maintained.

In SURMOUNT-OSA, tirzepatide reduced AHI both in people not using PAP and in people continuing PAP. That suggests the two can be complementary. For people who struggle with CPAP, weight loss may reduce severity, but it does not replace a proper discussion with a sleep specialist.

Never stop CPAP without advice

Feeling better and sleeping more soundly after losing weight is encouraging, but it is not proof that OSA has resolved. OSA can persist at a level that still affects health without obvious symptoms. Your sleep service can arrange a repeat sleep study, often at home, to measure your AHI before any change to CPAP. The DVLA may also need to know about changes in your condition.

Other treatments for OSA

Weight management is one part of a broader approach. NICE NG202 and NHS guidance describe other options, depending on severity and individual circumstances:

• Lifestyle measures: reducing alcohol, especially in the evening, stopping smoking, and avoiding sedative medicines where possible
• Positional therapy: for people whose apnoea occurs mainly when sleeping on their back
• Mandibular advancement devices: custom-fitted mouthguards that bring the lower jaw forward, often used in mild OSA
• Surgery: in selected cases, such as enlarged tonsils
• Bariatric surgery: for some people with severe obesity, which can substantially improve OSA. See our guide to GLP-1 medication vs bariatric surgery.

What about other GLP-1 medicines?

Semaglutide (Wegovy) and liraglutide (Saxenda) also produce weight loss that may improve OSA, but SURMOUNT-OSA is the largest dedicated trial of a GLP-1-based medicine specifically in OSA so far. Any medicine producing meaningful weight loss would be expected to help OSA to some extent, but the size of benefit will differ. Our comparison of Mounjaro and Wegovy discusses the differences in weight loss seen in trials, including the head-to-head SURMOUNT-5 study.

Things to consider if you have OSA and are thinking about tirzepatide

Getting a diagnosis first

If you suspect sleep apnoea but have not been diagnosed, the first step is to see your GP, who can refer you to a sleep service. Untreated OSA has health and safety implications regardless of weight-loss treatment.

Anaesthesia and sedation

People with OSA already need extra care during anaesthesia because of airway risks. GLP-1 medicines add a further consideration because they slow stomach emptying. If you have surgery planned, tell your team about both. See our guide to GLP-1 medication before surgery and anaesthesia.

Alcohol and sedatives

Alcohol relaxes the throat muscles and worsens OSA. It can also worsen nausea on tirzepatide. Reducing alcohol may help on both fronts. Sleeping tablets and some other sedatives can also worsen OSA.

Long-term treatment

Because OSA tends to worsen again if weight is regained, the long-term plan matters. Many people regain weight after stopping GLP-1 medicines. Our guides to Mounjaro maintenance and weight regain after stopping discuss the evidence.

Private treatment

If you consider private treatment, a responsible provider should ask about your OSA, your CPAP use and your other medical conditions, and should encourage you to stay in contact with your sleep service and GP. Costs vary between providers and doses; we do not list prices in our guides, but our price comparison explains what affects cost, and our provider comparison shows how regulated services differ.

What the trials do not tell us

SURMOUNT-OSA was well designed, but it leaves several questions open. Being aware of them helps set realistic expectations.

• People with diabetes were not included. Weight loss with tirzepatide tends to be somewhat smaller in people with type 2 diabetes, so the effect on OSA may differ. Many people with OSA also have diabetes.
• One year of follow-up. We do not yet have long-term trial data on whether improvements in OSA are sustained over many years of treatment, or what happens after stopping.
• Hard outcomes. The trials measured AHI, oxygen levels, blood pressure and symptoms, not heart attacks, strokes, road accidents or deaths.
• Mild OSA. Only people with moderate-to-severe OSA were studied. The effect in mild OSA is less clear.
• Not everyone responded the same way. Some participants improved a great deal; others much less. There is no reliable way to predict in advance how an individual will respond.
• Comparisons with other approaches. The trials compared tirzepatide with placebo, not with CPAP alone, mandibular devices or bariatric surgery.

Recognising OSA

Many people with OSA do not know they have it. It is often a partner who first notices. Clinicians sometimes use short questionnaires to judge how likely OSA is and how much it affects daily life:

• The Epworth Sleepiness Scale asks how likely you are to doze off in everyday situations, such as watching television or sitting as a passenger in a car. Higher scores suggest more daytime sleepiness.
• The STOP-Bang questionnaire combines snoring, tiredness, observed pauses in breathing, blood pressure, BMI, age, neck size and sex to estimate the likelihood of OSA.

These tools help decide who needs testing, but they do not diagnose OSA. Diagnosis needs a sleep study, which in the UK is often done at home with a portable monitor.

If you are taking or considering a weight loss medicine and recognise symptoms such as loud snoring, witnessed pauses in breathing or marked daytime sleepiness, mention them to your GP. Treating weight and investigating possible OSA can happen alongside each other.

Practical tips while losing weight with OSA

If you have OSA and are on tirzepatide or another weight management treatment, some practical steps may help:

• Keep using CPAP as prescribed unless your sleep service advises otherwise. As weight changes, your mask may fit differently, so tell your CPAP provider if it starts leaking or feels uncomfortable.
• Some CPAP machines adjust pressure automatically, while others are set to a fixed pressure. If your sleep needs change with weight loss, your sleep service can review the settings.
• Keep a simple record of your weight, how sleepy you feel during the day and any comments from your partner about snoring. This is useful for your next review.
• Avoid alcohol in the evening, which worsens airway collapse and can increase nausea.
• Eat your last meal earlier if reflux at night is a problem, which is a common side effect of GLP-1 medicines. Our guide to reflux, burping and indigestion has more ideas.
• Stay active. Physical activity supports weight loss and muscle strength, and may help sleep quality.

Questions to ask your sleep team or prescriber

• How severe is my OSA, and what is my current AHI?
• Would weight loss be expected to make a meaningful difference in my case?
• Should I continue CPAP while taking a weight loss medicine?
• When should I have a repeat sleep study?
• Do I need to tell the DVLA about my condition, and would any change affect that?
• Is there anything about my airway, such as enlarged tonsils or jaw shape, that weight loss would not address?

Who should not take tirzepatide

The Mounjaro SmPC lists contraindications and cautions, including hypersensitivity to the medicine, and cautions for people with a history of pancreatitis, severe gastrointestinal disease, and diabetic eye disease. It should not be used in pregnancy or while breastfeeding, and MHRA guidance advises effective contraception. Tirzepatide may reduce the effectiveness of oral contraceptives, so additional precautions are advised when starting and after dose increases. Our guide to who should not take GLP-1s covers this in detail.

When to speak to a professional

See your GP if you or your partner notice loud snoring with pauses in breathing, waking up gasping or choking, or persistent daytime sleepiness. If you already have OSA, talk to your sleep service before changing your CPAP use, and to your GP or prescriber before starting tirzepatide.

While taking tirzepatide, contact your prescriber if you have persistent nausea or vomiting, cannot keep fluids down, or notice your sleepiness worsening rather than improving.

Seek urgent medical help (call NHS 111, or 999 in an emergency) if you have:

• severe, persistent abdominal pain, which may spread to your back, with or without vomiting (a possible sign of pancreatitis)
• pain in the upper right abdomen with fever or yellowing of the skin or eyes
• chest pain, a very fast or irregular heartbeat, or severe breathlessness
• signs of a severe allergic reaction, such as swelling of the face or throat, or difficulty breathing

If you feel dangerously sleepy, do not drive. Suspected side effects can be reported to the MHRA through the Yellow Card scheme.