When you switch pharmacy, tell the new prescriber about current and recent GLP-1 side effects, even ones you think are normal. Write down each symptom, when the symptom started and how it affects eating and drinking. For severe or worrying symptoms, get a medical assessment. Changing pharmacy is no answer to those symptoms.
What to write down about your side effects
Tell every new pharmacy about your side effects, each time you switch. Write down:
- Each symptom: when it began and how long it lasts.
- The effect on you: how the symptom affects eating, drinking and daily activity.
- Your medicine: the name, the strength and any recent dose change.
- Other medicines you take.
Leave the cause to the prescriber (the doctor, nurse or pharmacist who approves your medicine). Symptoms may have more than one explanation.
MedExpress asks about recent side effects and severe symptoms when reviewing a switch. Answer “no symptoms” only if the answer is true, never to get an order through faster. If you switch pharmacy every month, give the same honest answer each time.
Pancreatitis warning signs needing urgent help
Use NHS 111 for urgent help where needed, and contact your prescriber about treatment. A pharmacy’s order-support inbox may not be checked as an urgent clinical service.
Vomiting, diarrhoea and dehydration on GLP-1 medicines
Vomiting or diarrhoea can lead to dehydration. The NHS lists signs such as dark urine, passing less urine and dizziness. If you cannot keep fluids down, or you are getting worse, get medical advice promptly. The right help depends on your symptoms and health conditions.
Do not hide these symptoms from a new pharmacy or expect a new brand to fix them. A prescriber needs to assess the problem.
Questions to ask your prescriber about side effects
- Are my symptoms likely to be linked to treatment or to another cause?
- Do I need urgent assessment or tests?
- What should I do about my next dose?
- Should my treatment plan change, and if so, how?
- How and when should I report my progress?
Keep the prescriber’s reply with your treatment history. Report suspected medicine side effects through the official MHRA Yellow Card service. A report does not replace medical care.
Questions before your next GLP-1 dose
Read going up, staying the same or reducing a dose for questions to ask your prescriber. If you have missed treatment, use the missed-dose and longer-break guide to build an accurate timeline.
Frequently asked questions
Should I tell a new pharmacy about my GLP-1 side effects?
Yes. Tell the new prescriber about current and recent GLP-1 side effects, even ones you think are normal. MedExpress, for example, asks about recent side effects and severe symptoms when reviewing a switch. Answer “no symptoms” only if the answer is true.
What stomach pain on a GLP-1 medicine needs urgent help?
Severe, persistent stomach pain, especially pain spreading to your back, needs urgent medical help. MHRA guidance highlights this as a possible sign of pancreatitis. Call 999 for life-threatening symptoms such as severe breathing difficulty or collapse.
What are the signs of dehydration from vomiting or diarrhoea?
The NHS lists dark urine, passing less urine and dizziness as signs of dehydration. If you cannot keep fluids down during GLP-1 treatment, or you are getting worse, get medical advice promptly.
How do I report a side effect from a weight-loss medicine?
Report suspected medicine side effects through the official MHRA Yellow Card service. A Yellow Card report does not replace medical care, so contact your prescriber or NHS 111 about the symptoms as well.
Sources
Links checked on 6 October 2026. Provider prices and policies change, so confirm the details with the provider before you pay. The organisations linked here have not reviewed or endorsed this guide.
- MedExpress: information needed when switching GLP-1 medicines
- MHRA: strengthened warnings about acute pancreatitis
- NHS: dehydration
Pharmacy Hopper does not give medical advice. Read our editorial standards.