Diabetes medicines: GLP-1 agonists

This information is about medicines called glucagon-like peptide 1 (GLP-1) agonists. It explains how these medicines, together with healthy lifestyle changes, can help you to manage type 2 diabetes.

The information covers:

We also have a booklet called "GLP-1 agonist medicines for diabetes", which you or your healthcare professional can print.

If you have any questions, please speak to your healthcare professional.

How GLP-1 agonist medicines work

GLP-1 agonists are medicines used to treat type 2 diabetes. They mimic (copy) the action of a hormone (chemical substance) called GLP-1. Your stomach naturally releases this hormone when you eat food.

The medicines work in different ways. They:

  • help your body to make more insulin (the hormone that controls the amount of sugar in your blood) when needed
  • reduce the amount of sugar (glucose) that your liver makes
  • slow down the digestion of food, so that it takes longer for your body to absorb (take in) the sugar from meals
  • can reduce your appetite

Taking GLP-1 agonist medicines

You can take GLP-1 agonist medicines as injections or tablets.

If you have injections, your healthcare professional will tell you the best place to inject the medicine. This may be under the skin in:

  • the front of your thighs
  • your tummy (abdomen)
  • your upper arms

If you have tablets, you take a tablet 1 time each day when you wake up on an empty stomach. You swallow the tablet with a sip of water (no more than half a glass or 120ml). Please wait for at least 30 minutes before eating, drinking or taking any other tablets.

You healthcare professional explains:

  • how much medicine to take (the dose)
  • when to take the medicine
  • how often to take the medicine

We give you a printed patient booklet, where you can keep a record of the instructions for taking your medicine.

We may need to make some changes to your other diabetes medicines. We explain these changes to you and list them in your printed patient booklet.

Make sure that you keep taking all your other medicines as before, unless we tell you otherwise.

Side effects of GLP-1 agonist medicines

Before you start taking GLP-1 agonist medicines, it is important that your diabetic eye screening is up to date. This is a test that you have every year to check for eye problems caused by diabetes. Please tell your healthcare professional if there are any concerns about your eyes before you start GLP-1 agonist medicines. They can then make sure that you have the most suitable medicines to treat your diabetes.

The patient information leaflet that comes with your GLP-1 agonist medicines has a full list of possible side effects. You are unlikely to have all the side effects listed and may not get any of them.

The most common possible side effects of GLP-1 agonist medicines include:

  • feeling sick (nausea) and diarrhoea (these usually go away with time)
  • stomach pains
  • constipation (when you find it hard to poo or go to the toilet less often than usual)
  • having less appetite
  • low blood sugar (hypoglycaemia or hypos)
  • headaches
  • skin reactions if you inject your medicine

Stop taking the medicine and contact a doctor immediately if:

you have severe and long-lasting stomach pain (which might reach through to your back), with or without being sick (vomiting). This may be a sign that your pancreas is inflamed.

You can make a note of any side effects in your printed patient booklet. Please talk to your healthcare professional about them.

Treatment aims and how we monitor you

GLP-1 agonist medicines can improve your blood sugar control if you have type 2 diabetes. They can also help you to lose weight, together with diet and healthy lifestyle changes. We usually prescribe these medicines for people who cannot control their type 2 diabetes with tablets.

We take some measurements before you start the GLP-1 agonist medicine and then repeat them after 3 and 6 months:

  • Glycated haemoglobin or HbA1c (this blood test measures how well your diabetes has been controlled over the past 3 months).
  • Your weight.
  • How well your kidneys work (we do a blood test to help us estimate how many millitres of waste your kidneys can filter in a minute).

These measurements help us to see if the medicine and lifestyle changes have improved your diabetes control. We can also check for any side effects of the medicine.

In your printed patient booklet, we record the targets for your blood sugar control and weight loss after 6 months. We then review if you have met these targets.

Healthy changes to your diet

To help you manage type 2 diabetes, lose weight and stay healthy, you may need to make changes to your diet.


  • eat small, regular meals and spread your food over the day
  • choose high-fibre, starchy foods, such as wholegrain breads and cereals, beans, peas, lentils and oats
  • eat fruit and vegetables every day
  • include vegetables or salad with each meal
  • spread the fruit that you eat over the day because all fruit contains natural sugar
  • use small amounts of mono-unsaturated fats and oils, such as olive oil and rapeseed oil (vegetable oil)
  • eat fewer fried foods and cut fat off all meat
  • eat leaner (less fatty) meats, such as chicken or turkey
  • use artificial sweeteners instead of sugar, honey, glucose or fructose
  • replace energy drinks, Lucozade and malt drinks with diet or no added sugar varieties


  • do not have large portions of starchy carbohydrates, such as potatoes, bread, rice and pasta. Add extra vegetables or salad to your plate instead
  • do not drink more than about 125ml of fruit juice a day because it contains natural sugar
  • do not eat large amounts of saturated fats, such as butter, lard, ghee, red palm oil, pastry, cheese, crisps, mayonnaise and cakes
  • do not eat too many sugary foods and drinks
  • do not eat too much salt. Flavour food with pepper, garlic, herbs and spices instead
  • do not drink more than 14 units of alcohol a week, which you should spread over 3 or more days. 14 units are about 6 pints of average strength beer or 6 medium (175ml) glasses of average strength wine

Dinner plate model to help with weight loss

A healthy dinner plate is made up of these types of foods:

  • Half the plate (50%) should have vegetables, salad or fruit.
  • One-quarter of the plate (25%) should have protein, such as meat, fish, eggs, beans or lentils.
  • One-quarter of the plate (25%) should have starchy carbohydrate foods, such as bread, potatoes, pasta, rice, yams or cassava.

Making healthier food choices

This table gives you guidance on replacing some foods with healthier choices.

Limit these foods Replace with these foods
sugar (white or brown), honey, glucose, fructose powder artificial sweetener, such as Canderel®, Splenda®, Sweetex or Hermesetas

cereals coated in sugar or honey, such as Crunchy Nut Cornflakes, Frosties, Coco Pops or sweet oatmeal

high-fibre, unsweetened cereals, such as porridge oats, Fruit and Fibre, Weetabix, sugar-free muesli or Shredded Wheat
regular soft drinks, Nutrament malt drinks such as Supermalt, energy drinks such as Lucozade or Red Bull water (still or sparkling), no added sugar squash, diet fizzy drinks
drinking chocolate, malted hot drinks such as Milo or Horlicks low-calorie drinking chocolate, such as Options, Highlights or Ovaltine Light
sweets, chocolate, cake, ice cream limit chocolate and cakes to special occasions (be aware that low-fat options may be high in sugar)
chocolate biscuits, jam or cream-filled biscuits plain biscuits, such as rich tea, ginger nut or Hovis® biscuits (limit to 2 biscuits)
savoury biscuits, such as butter puffs, Ritz crackers or Tuc crackers plain crackers, water crackers, oat cakes, crisp breads such as Ryvita (use a low-fat spread)
dried fruit (limit to 1 tablespoon at a time) fresh or frozen fruit
fruit, canned in syrup fruit, canned in natural juice
fruit juice (limit any type of fruit juice to about 125ml a day) no added sugar squash
fried food grilled, poached, boiled or baked food
pastry, croissant scone, currant bun, English muffin
coconut milk, coconut cream semi-skimmed or skimmed milk (fresh, long-life or powdered)
salad cream, mayonnaise, coleslaw low-fat French or vinaigrette dressing, vinegar, lemon juice, low calorie salad cream or mayonnaise (1 to 2 teaspoons)

Booklet for people taking GLP-1 agonist medicines

You or your healthcare professional can print our booklet called GLP-1 agonist medicines for diabetes. This has been designed for people with type 2 diabetes taking GLP-1 agonist medicines.

The booklet can help you to monitor and manage your condition with a healthcare professional’s support. There are various sections that you and your healthcare professional can complete together. For example, you can:

  • write important information about the GLP-1 agonist medicine that has been prescribed for you
  • make a note of any side effects
  • list any changes to your other diabetes medicines
  • record the measurements that we take to monitor your health (your blood test results and weight)
  • set targets for your blood sugar control and weight loss over 6 months
  • plan the changes that you will make to have a healthier lifestyle

Resource number: 4520/VER3
Last reviewed: October 2022
Next review due: October 2025

A list of sources is available on request.

Contact us

If you need medical advice, please contact the diabetes department or Southwark community diabetes team.

Diabetes department

Phone: 020 7188 1993, Monday to Friday, 9am to 5pm

If we cannot answer your call, please leave a voicemail. We call you back within 1 working day. Out of hours, please contact your GP, go to 111.nhs.uk or call 111.

Email: [email protected]

We respond to your email within 1 working day.

Southwark community diabetes team

Phone: 020 3049 8863

Please leave a voicemail message with your full name, date of birth, NHS number and mobile phone number. We aim to call you back within 3 working days. If the matter is urgent, please explain this and we will try to respond by the end of the working day.

Email: [email protected]

We respond to your email within 1 working day.

Pharmacy medicines helpline

If you have any questions or concerns about your medicines, please speak to the staff caring for you.

You can also contact our pharmacy medicines helpline.

Phone: 020 7188 8748, Monday to Friday, 9am to 5pm

Email: [email protected]

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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