Independent UK medicine guidance
Mounjaro nausea and vomiting: what helps?
Nausea is one of the most frequently reported Mounjaro side effects. Vomiting is also listed as very common when tirzepatide is used for weight management. In adults treated for type 2 diabetes, vomiting and stomach pain are listed as common rather than very common, although both were very common in the type 2 diabetes cardiovascular disease study reported in the leaflet revised in August 2026.
Key facts
- Vomiting is a very common side effect of Mounjaro in weight management: more than 1 in 10 people (UK leaflet, revised August 2026).
- In adults treated for type 2 diabetes it is common, up to 1 in 10. In the type 2 diabetes cardiovascular disease study it was very common.
- Nausea and vomiting are most likely in the first weeks and after each dose increase, and usually settle as the body adjusts.
- Repeated vomiting raises the risk of dehydration, which can affect the kidneys. Keep fluids up and seek advice if you cannot keep liquids down.
- Vomiting with severe stomach pain that spreads to your back needs same-day assessment. See the warning signs below.
In pooled weight-management studies, nausea affected approximately 24.6% to 29% of participants taking tirzepatide, compared with 8.5% taking a placebo. These digestive side effects were generally mild or moderate, happened more often while doses were being increased and became less frequent over time.
Why can Mounjaro make you feel sick?
Mounjaro regulates appetite and slows the rate at which food leaves your stomach. This helps you feel full for longer, but it can also leave you feeling uncomfortably full or nauseous, particularly after a large, rich or fatty meal.
Symptoms are often more noticeable:
- After starting treatment
- Following a dose increase
- During the first few days after an injection
- After eating beyond the first feeling of fullness
- After fatty, fried, spicy or very sweet foods
- If you drink alcohol
- When constipation or reflux is also present
What may help?
Try eating smaller portions and stopping as soon as you feel comfortably full. Eat slowly, choose relatively plain or lower-fat foods and avoid lying down immediately after a meal.
Cold foods, crackers, toast, soups or other foods with little smell may be easier to tolerate. Take small, frequent sips of fluid rather than drinking a large amount at once.
Do not force yourself to finish a meal simply because it is smaller than you would previously have eaten.
If nausea is stopping you from eating or drinking properly, contact your prescriber. They may recommend remaining at your current dose for longer, changing your treatment plan or considering suitable anti-sickness medication. Do not increase, reduce or stop Mounjaro without discussing it with them.
When should you get help?
Contact your prescriber, GP or NHS 111 if you:
- Keep being sick
- Cannot keep fluids down
- Are passing very little urine
- Feel unusually weak, confused, faint or persistently dizzy
- Have vomit containing blood or material resembling coffee grounds
- Have symptoms that are worsening rather than settling
Warning sign of pancreatitis: severe, persistent pain in the upper abdomen, especially when it spreads through to the back. Stop using Mounjaro and seek immediate medical help if this happens.
Possible gallbladder problem: vomiting accompanied by severe right-sided abdominal pain, fever or yellowing of the skin or eyes also needs urgent assessment.
Evidence update, September 2026: SURPASS-CVOT nausea and vomiting figures in the revised SmPC
On 8 September 2026 the electronic medicines compendium (eMC) published a revised Mounjaro Summary of Product Characteristics with a text revision date of 29 August 2026. It adds safety results from SURPASS-CVOT, a large trial that compared tirzepatide with dulaglutide, another injectable diabetes medicine, in adults with type 2 diabetes and established cardiovascular disease. The study-specific figures relevant to this page are:
- Nausea: 25.1% of participants taking tirzepatide
- Vomiting: 11.6%
- For context, the same study reported diarrhoea in 24.9%, constipation in 12.8% and abdominal pain in 10.5%
The figures substantiate the frequency-category changes made in the UK patient leaflet revised in August 2026 and already reported on this page. They do not add a new side effect and they do not change any of the advice above about when to get help.
Source: Mounjaro Summary of Product Characteristics (eMC), text revised 29 August 2026, section 4.8
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