Jabwise

Common side effects, and when to get help

Feeling or being sick, constipation, diarrhoea, tiredness, hair loss and itchy or red skin where you inject are on the NHS lists for semaglutide and tirzepatide. Its advice is short: speak to a pharmacist or doctor if one bothers you or doesn’t go away, and keep taking your medicine unless you’re advised to stop.

The common ones

Semaglutide is the medicine in Wegovy and Ozempic; tirzepatide is the one in Mounjaro and Zepbound. Each cell quotes the NHS page for that medicine.

Side effectSemaglutideTirzepatide
Feeling or being sickfeeling sick (nausea) and being sick (vomiting)NHS: Semaglutidefeeling sick (nausea) or being sick (vomiting)NHS: Tirzepatide
ConstipationconstipationNHS: Semaglutideconstipation or diarrhoeaNHS: Tirzepatide
DiarrhoeadiarrhoeaNHS: Semaglutideconstipation or diarrhoeaNHS: Tirzepatide
Stomach painNot on the liststomach painNHS: Tirzepatide
Tirednessfeeling tiredNHS: Semaglutidefeeling tiredNHS: Tirzepatide
Skin where you injectitchy or red skin where you injectNHS: Semaglutideitchy or red skin where you injectNHS: Tirzepatide
Hair losshair lossNHS: Semaglutidehair lossNHS: Tirzepatide

What the NHS says to do

  • If one bothers you

    If a side effect bothers you or doesn’t go away, the NHS says a pharmacist or doctor may give advice on how to reduce it.

  • On stopping

    Unless you’re advised to stop, the NHS says keep taking it. If you want to stop, talk to your doctor; don’t stop suddenly.

  • Alcohol

    The NHS says it’s best not to drink alcohol, because it can increase side effects like feeling sick or being sick.

  • Dizzy, or vision problems

    If you feel dizzy or have vision problems, the NHS says don’t drive, ride a bike or use machinery until they’ve gone.

Rarer, and serious

The NHS says most are rare, and to call 111 if you think you’re having one.

Side effectAs the NHS describes itListed for
Allergic reaction (anaphylaxis)symptoms such as a swollen throat or tongue, a raised, itchy rash or difficulty breathingNHS: SemaglutideBoth
An inflamed pancreassevere pain in your stomach or back, which does not go awayNHS: TirzepatideBoth
Low blood sugarmore likely if used with other diabetes medicinesNHS: TirzepatideBoth
Gallstones or a swollen gallbladdersevere tummy painNHS: TirzepatideTirzepatide
Eye changessudden loss of vision, usually in one eye at a timeNHS: SemaglutideSemaglutide

Questions

Are these all the side effects?

No. The NHS says these are not all of them, and points you to the leaflet that comes with your medicine for the full list.

Should I stop if I get side effects?

The NHS says to keep taking your medicine unless you’re advised to stop, and to talk to your doctor if you want to stop rather than stopping suddenly.

How do I report a side effect?

In the UK, on the Yellow Card website, which both NHS pages link to. Anyone can report, not only doctors. In the US, the FDA’s MedWatch takes reports from the public.

Side effects

Jabwise keeps your side effects in one place.

Each check-in asks “Any side effects currently?”, a tap per answer. Side Effects then counts the days you felt each one, over 7, 30 or 90 days, ready for your next review.

Jabwise Side Effects: constipation on 2 of 6 days with a check-in, over the last 7 days

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