Metformin
Also known as: Glucophage
What it's for
Metformin helps control blood sugar levels in type 2 diabetes. It makes your body respond better to insulin and reduces the amount of sugar your liver releases.
Comes as: Tablets or liquid
How to take it
- Adults: Usually start with 500mg once or twice a day with meals.
- Your doctor may gradually increase the dose.
- Take with or just after food to reduce stomach side effects.
- Do not stop taking it without talking to your doctor.
Doses here are typical. Always follow the instructions from your prescriber or on the packet — they come first.
Common side effects
- Feeling sick, especially when you first start taking it
- Stomach pain, diarrhoea, or loss of appetite
- A metallic taste in your mouth
The leaflet inside the packet lists all known side effects.
Important safety points
- Tell your doctor if you have kidney problems
- Avoid drinking too much alcohol
- You may need to stop taking it before surgery or medical tests - ask your doctor
- Can cause low blood sugar if combined with other diabetes medicines
Get medical help urgently if…
- You feel very weak, tired, or unwell
- You have unusual muscle pain
- You have difficulty breathing
- You have stomach pain with nausea and vomiting
- You feel very cold or your skin looks blue
Call NHS 111 for urgent advice, or 999 if someone is seriously unwell.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.