Understanding medicine

Most people need medicine to control their type 2 diabetes.

This helps keep your blood sugar level as normal as possible to prevent health problems.

You may have to take it for the rest of your life, although your medicine or dose may need to change over time.

Adjusting your diet and being active is usually also necessary to keep your blood sugar level down.

Medicines for type 2 diabetes

There are many types of medicine for type 2 diabetes. It can take time to find a medicine and dose that's right for you.

You'll usually be offered a medicine called metformin first.

You may need to take extra medicines, or a different medicine such as insulin, if:

Your GP or diabetes nurse will recommend the medicines most suitable for you.

Your medicine might not make you feel any different, but this does not mean it's not working. It's important to keep taking it to help prevent future health problems.


Metformin is the most common medicine used for type 2 diabetes. It can help keep your blood sugar at a healthy level.

It comes as tablets.

Common side effects of metformin include feeling sick and diarrhoea. If this happens to you, your doctor may suggest trying a different type called slow-release metformin.

Find out more about metformin

Other diabetes medicines

If metformin does not work well enough on its own, you cannot take it or you have other health problems, you may need to take other medicines alongside or instead of metformin.

These include:


You'll need insulin if other medicines no longer work well enough to keep your blood sugar below your target.

Sometimes you may need insulin for a short time, such as if you're pregnant, if you're ill, or to bring your blood sugar level down when you're first diagnosed.

You inject insulin using an insulin pen. This is a device that helps you inject safely and take the right dose.

Using an insulin pen does not usually hurt. The needles are very small, as you only inject a small amount just under your skin. Your diabetes nurse will show you where to inject and how to use your pen.

Your GP or diabetes specialist will recommend the type of insulin treatment that's best for you.

Find out more about insulin

Side effects

Your diabetes medicine may cause side effects.

The side effects you may get depend on which medicines you're taking.

Do not stop taking your medicine if you get side effects. Talk to your doctor, who may suggest trying a different medicine.

Low blood sugar (hypos)

Some diabetes medicines can cause low blood sugar, known as hypoglycaemia or a hypo. These medicines include insulin and medicines such as gliclazide.

If you take medicine that can cause hypos, your doctor might recommend that you check your blood sugar regularly. You'll be given a testing kit and shown how to do a finger-prick test.

If you take insulin at least twice a day and have frequent or severe hypos, you might also be offered a continuous glucose monitor (CGM) or flash monitor.

This is a small sensor you wear on your skin that lets you check your blood sugar level at any time.

Learn more about checking your blood sugar levels from Diabetes UK

You'll need to check the DVLA rules about driving if you take medicine that can cause hypos.

Learn more about diabetes and your driving licence from Diabetes UK

How to get free prescriptions for diabetes medicine

If you take diabetes medicine, you're entitled to free prescriptions for all your medicines, including medicines for other conditions.

To claim your free prescriptions, you'll need to apply for an exemption certificate.

To apply for an exemption certificate:

If you have to pay for diabetes medicine before you receive your exemption certificate, save your receipts and ask the pharmacist to give you an FP57 receipt and refund claim form. You can use this to claim the money back after you receive your certificate.

Travelling with diabetes medicines

If you're going on holiday:

Page last reviewed: 22 December 2023
Next review due: 22 December 2026