Jabwise

Feeling sick on a GLP-1

Mounjaro’s, Wegovy’s and Ozempic’s leaflets list feeling sick as very common, more than 1 in 10 people, and both NHS pages list it. In two Zepbound trials, 25% to 29% reported nausea, against 8% on placebo. Mounjaro’s leaflet says it’s most common when first starting, and decreases over time in most patients.

Reported nausea in Zepbound’s trials8%Placebo25%5mg29%10mg28%15mg

How common it is

Each leaflet’s own words for how common it is, quoted as written. Zepbound’s figures are the share of people in its two weight trials who reported it.

MedicineFeeling sickBeing sick
MounjaroVery common (may affect more than 1 in 10 people)Mounjaro KwikPen patient leafletVery common for weight management; common in adults treated for type 2 diabetes
Zepbound25% to 29%, against 8% on placebo8% to 13%, against 2% on placebo
WegovyVery common: may affect more than 1 in 10 peopleWegovy FlexTouch patient leafletVery common: may affect more than 1 in 10 peopleWegovy FlexTouch patient leaflet
OzempicVery common (may affect more than 1 in 10 people)Ozempic patient leafletCommon (may affect up to 1 in 10 people)Ozempic patient leaflet

What else they say

  • Most common at the start

    Mounjaro’s leaflet says feeling sick is usually not severe, most common at first, and decreases over time in most patients.

  • While the dose goes up

    Zepbound’s label says most nausea, vomiting and diarrhoea in its trials came while the dose was going up, then decreased.

  • Fluids

    Wegovy’s and Ozempic’s leaflets say being sick can cause dehydration, and that drinking fluids is important to prevent it.

  • Stopping for gut side effects

    In two Zepbound trials, 1.9% to 4.3% stopped treatment due to stomach and gut side effects, against 0.5% on placebo.

Questions

Is nausea a side effect of Mounjaro?

Yes. Mounjaro’s leaflet lists feeling sick as very common, more than 1 in 10 people, and says it’s usually not severe and decreases over time in most patients.

Does alcohol make it worse?

Both NHS pages say alcohol can increase side effects like feeling or being sick. The semaglutide page says it’s best not to drink it; the tirzepatide page, best to avoid it.

When is it serious?

Mounjaro’s, Wegovy’s and Ozempic’s leaflets say stop using it and seek urgent medical help for severe, persistent stomach pain, with or without nausea and vomiting, as it could be pancreatitis.

Patterns

See where it falls in your jab week.

Tap Nausea or Vomiting in a check-in. After 8 regular jab weeks, After Your Jab counts the days you felt each, and names a day of your jab week if one stands out.

Jabwise After Your Jab: food noise quietest the day after a jab in 10 of 10 weeks, with wind on 14 days and nausea and constipation on 7

Sources

General information, not medical advice. Follow your prescriber’s guidance.

Getting real advice

We’re not doctors. This page sums up what the NHS and the official medicine information say, and can’t tell you what’s right for your body: your prescriber’s instructions and the leaflet in your box come first. More in our terms.

  • Quoted from official sources, each one linked
  • Sources checked 12 October 2026
  • No dosing advice; your prescriber comes first