THE SHORT VERSION
- Digestive symptoms are common, but persistent or severe symptoms need review.
- Sudden vision loss or rapidly worsening eyesight needs urgent assessment.
- Use the leaflet for your own Wegovy formulation.
Act promptly on eye symptoms and severe pain
Sudden loss of vision, including partial loss, or eyesight that worsens rapidly needs urgent assessment at eye casualty or A&E. The MHRA has warned of a very rare association between semaglutide and an eye condition called NAION. You do not need to diagnose the cause before seeking help.
Stop using Wegovy and seek urgent medical help for severe, persistent abdominal pain, with or without vomiting, especially pain that reaches the back. This may indicate pancreatitis. Call 999 for breathing difficulty, tongue or throat swelling, or collapse suggesting a serious allergic reaction. These situations should not wait for an online consultation response.
Dehydration changes the urgency
Vomiting and diarrhoea can cause fluid loss. Pay attention to much less urine, dark urine, persistent dizziness on standing or unusual tiredness. NHS advice is to seek an urgent GP appointment or help from NHS 111 for signs of serious dehydration. Confusion, difficulty breathing or being difficult to wake needs emergency help.
If you are mildly unwell and able to drink, try small sips. A pharmacist can advise on rehydration products and whether they suit your health conditions. Do not wait for a specific number of hours if you are becoming more unwell. Tell the clinician what you have managed to drink and whether you have a condition that limits your fluid intake.
Separate a symptom list from your own experience
The leaflet includes effects that have occurred in some people; it does not predict what will happen to you. Nausea, vomiting, diarrhoea and constipation are among the recognised digestive effects. Tell your prescriber if symptoms are persistent, worsening or making it difficult to manage normal meals and fluids.
Keep the description simple: when it began, whether it is constant or comes and goes, and what has changed in your day. Mention other illnesses and new medicines too. A clinician may need to consider causes beyond Wegovy. Avoid assuming that every new symptom is harmless just because somebody online reported something similar.
Discuss symptom treatment before adding more medicines
Ask a pharmacist or prescriber about persistent constipation, reflux or nausea. Tell them what you already take and anything you have tried, including products bought online. A remedy that helped a friend may not fit your own medicines or health history.
Symptoms can have several causes, so describe them rather than asking only for a particular treatment. For example, say whether constipation comes with pain, swelling or vomiting. Severe abdominal pain or a suspected bowel obstruction needs urgent assessment. Do not use a symptom remedy to push through worsening illness or to make an independently chosen increase tolerable. Any change to prescribed treatment should come from the clinical team.
Make aftercare easy to use
Save the dispensing pharmacy's contact details and the prescriber's clinical support route. If vomiting or diarrhoea is stopping you from keeping fluids down, seek urgent advice rather than trying to manage it until the next review. Tell the clinician if you have kidney problems or diabetes, because this can affect the assessment.
For less urgent symptoms, agree a clear next step and a time to check back. Ask before starting remedies or changing your prescription. Bring the pack or a photo of the label when seeking advice so the clinician knows whether you use tablets or injections. A Yellow Card report can record a suspected reaction alongside, not instead of, getting care.
Record the advice and arrange the next review
After a consultation, write down what was agreed, who gave the advice and when to get back in touch. Ask what you should do if symptoms return before that review. If you have been assessed urgently, make sure your regular prescriber knows the outcome before the next prescription is issued.
When reporting an effect, name the formulation as well as Wegovy: tablet or injection. Keep the batch details if available, particularly for a Yellow Card report. A report records a suspected link; it does not by itself prove that the medicine caused the symptom. The practical priority is getting the right care and an individual decision about what happens with treatment next.
Sources you can check
- Wegovy injection: UK patient information leaflet
- MHRA: semaglutide and NAION
- NHS: semaglutide
- MHRA Yellow Card
- NHS: dehydration
- NHS: anaphylaxis
- NHS: acute pancreatitis
Editorial presentation updated 24 October 2026. This is general information, not individual medical advice or a claim of independent clinical review. Read the linked source and the leaflet supplied with your medicine for the full context. Suggest a correction.