GLP-1 Medication and Type 2 Diabetes

GLP-1 medicines were first developed to treat type 2 diabetes, and they remain an important part of diabetes care in the UK. Medicines such as Ozempic and Rybelsus (semaglutide), Trulicity (dulaglutide), Victoza (liraglutide) and Mounjaro (tirzepatide) lower blood sugar, usually help with weight loss and, for some, reduce cardiovascular risk. NICE updated its type 2 diabetes guideline (NG28) in February 2026, bringing GLP-1 medicines into earlier use for some groups, including people with obesity, established cardiovascular disease or early-onset diabetes. People with type 2 diabetes tend to lose somewhat less weight on these medicines than people without diabetes, and need particular care with low blood sugar and eye health.

How GLP-1 medicines work in type 2 diabetes

GLP-1 (glucagon-like peptide-1) is a hormone released by the gut after eating. GLP-1 receptor agonist medicines mimic it, with effects that include:

• Glucose-dependent insulin release. They help the pancreas release more insulin when blood sugar is high, but much less when it is normal. This is why they have a low risk of hypoglycaemia on their own.
• Lower glucagon. They reduce glucagon, a hormone that raises blood sugar.
• Slower stomach emptying. This reduces blood sugar spikes after meals.
• Reduced appetite. Acting on the brain, they help people feel full sooner and eat less, which supports weight loss.

Tirzepatide (Mounjaro) also activates GIP receptors, another gut hormone pathway involved in insulin release and metabolism. It is a dual GIP/GLP-1 receptor agonist. Our guide to how Mounjaro works explains this in more detail.

GLP-1 medicines used in type 2 diabetes in the UK

Product licences change, so always check the current SmPC. For a closer look at the two semaglutide injections, see Ozempic vs Wegovy, and for the tablet, Rybelsus and weight loss.

Diabetes products versus weight-management products

Some medicines exist in separate versions for diabetes and weight management, with different dose ranges and devices. In 2023, during supply shortages, UK health authorities advised that GLP-1 medicines licensed for diabetes, such as Ozempic, should not be prescribed off-label for weight loss, to protect supplies for people with diabetes. Mounjaro uses the same product for both indications.

What NICE recommends

The February 2026 NG28 update

NICE's guideline on managing type 2 diabetes in adults (NG28) was substantially updated in February 2026. Key changes relating to GLP-1 medicines, as summarised by NICE and professional commentators, include:

• Initial treatment: dual therapy with metformin (modified-release preferred) and an SGLT2 inhibitor is now the standard starting point for many adults, rather than metformin alone.
• Established atherosclerotic cardiovascular disease: triple first-line therapy with metformin, an SGLT2 inhibitor and subcutaneous semaglutide is recommended.
• Early-onset type 2 diabetes (diagnosed before 40): a GLP-1 medicine or tirzepatide may be considered as part of initial triple therapy or as the first additional treatment.
• Obesity: a GLP-1 medicine or tirzepatide should be considered as the first additional treatment when further glucose-lowering is needed.

The detail of the guideline is complex and depends on individual circumstances, including kidney function, heart failure, frailty and personal preferences. Your diabetes team will apply it to your situation. Check the current NG28 for the latest recommendations, as NICE has also signalled updates to related technology appraisals, including TA924 on tirzepatide for type 2 diabetes.

Weight-management guidance and diabetes

People with type 2 diabetes may also qualify for weight-management treatment under separate NICE technology appraisals, such as TA1026 for tirzepatide and TA875 for semaglutide (Wegovy). These have their own criteria based on BMI and weight-related conditions. In England, tirzepatide for weight management is being introduced in primary care in phases. Our guides to Mounjaro on the NHS and who can get weight-loss injections explain eligibility.

Weight loss in people with type 2 diabetes

People with type 2 diabetes tend to lose less weight on GLP-1 medicines than people without diabetes. The reasons are not fully understood but may include differences in metabolism, the effects of other diabetes medicines, and reduced loss of glucose in the urine as blood sugar improves.

In SURMOUNT-2, around 79% to 83% of people on tirzepatide lost at least 5% of their body weight, compared with about a third on placebo. In STEP 2, 68.8% on semaglutide 2.4 mg lost at least 5%, compared with 28.5% on placebo.

These are average results from trials that included diet and activity support. Individual results vary widely. Our guide to realistic weight-loss expectations puts these figures in context.

Benefits beyond blood sugar and weight

GLP-1 medicines can have wider benefits for some people with type 2 diabetes:

• Cardiovascular outcomes. Several GLP-1 medicines have shown cardiovascular benefits in outcome trials in people with type 2 diabetes and high cardiovascular risk. This is one reason NICE now recommends semaglutide as part of first-line treatment for people with established cardiovascular disease.
• Blood pressure and cholesterol. Trials, including SURMOUNT-2, have reported improvements in measures such as systolic blood pressure and blood fats.
• Other conditions. Trials have studied some GLP-1 medicines in related conditions. The Mounjaro SmPC includes trial results in obstructive sleep apnoea and heart failure with preserved ejection fraction in people with obesity, and Wegovy is licensed for a type of fatty liver disease (MASH) in specific groups.

Whether these benefits apply to you depends on your health and which medicine you take.

Safety considerations specific to diabetes

Hypoglycaemia (low blood sugar)

GLP-1 medicines alone rarely cause hypos. The risk increases when they are taken with:

• Sulfonylureas such as gliclazide
• Insulin

The Mounjaro and Wegovy SmPCs advise that when starting treatment, prescribers should consider reducing the dose of insulin or sulfonylureas to lower the risk of hypoglycaemia. You may need to check your blood sugar more often.

The NHS lists symptoms of a hypo, which include sweating, feeling tired, dizziness, feeling hungry, tingling lips, shaking, a fast heartbeat, irritability, and blurred vision. Severe hypos can cause confusion, unusual behaviour, seizures or loss of consciousness. Follow your diabetes team's advice on treating a hypo, which usually involves fast-acting sugar such as glucose tablets or a sugary drink.

Diabetic retinopathy

The SmPCs warn that rapid improvement in blood glucose control has been associated with a temporary worsening of diabetic retinopathy. People with retinopathy should be monitored closely. Keep attending diabetic eye screening, and report any vision changes.

The Wegovy SmPC also mentions non-arteritic anterior ischaemic optic neuropathy (NAION), a rare eye condition. It notes that data from epidemiological studies may indicate an increased risk during semaglutide treatment, and that sudden loss of vision should be urgently assessed.

Dehydration and kidney function

Nausea, vomiting and diarrhoea can cause dehydration, which in rare cases can affect kidney function. This matters for people with diabetes who may already have reduced kidney function or take medicines such as SGLT2 inhibitors, ACE inhibitors or diuretics. Your diabetes team may give you "sick day rules" explaining which medicines to pause when you are unwell. Do not stop any medicine without this advice. See our guide to hydration on GLP-1 medication.

Pancreatitis and gallbladder problems

These are recognised but uncommon side effects across the class. In January 2026 the MHRA strengthened warnings on acute pancreatitis, including rare necrotising and fatal cases. People with diabetes already have a somewhat higher background risk of pancreatitis and gallstones. See our guides to GLP-1 medication and pancreatitis and gallbladder problems.

Not a substitute for insulin

The Wegovy SmPC states that semaglutide must not be used as a substitute for insulin. GLP-1 medicines are not used to treat type 1 diabetes or diabetic ketoacidosis.

Do not combine GLP-1 medicines

Two GLP-1 medicines should not be taken together. If you are switching, for example from Ozempic to Mounjaro, your prescriber will plan the transition.

Starting a GLP-1: what to expect

GLP-1 medicines are started at a low dose and increased gradually, usually every four weeks, to reduce digestive side effects. For example, the Mounjaro SmPC sets a starting dose of 2.5 mg once weekly, increasing to 5 mg after four weeks, with further 2.5 mg steps if needed after at least four weeks on each dose. Diabetes doses of other medicines follow their own schedules.

During the first few months you might notice:

• Reduced appetite and feeling full sooner
• Digestive side effects such as nausea, diarrhoea, constipation, indigestion and burping, most often after starting or increasing the dose
• Falling blood sugar readings, which may mean other diabetes medicines need adjusting
• Gradual weight loss, which often continues over many months

Your diabetes team will usually check your HbA1c after about three to six months to see how well the treatment is working. Whether treatment continues usually depends on how well you respond, in line with NICE guidance and local policies. Our guides to nausea, diarrhoea and reflux and burping cover common side effects.

Switching between GLP-1 medicines

People with type 2 diabetes sometimes switch between GLP-1 medicines, for example because of side effects, supply problems, updated NICE guidance or a need for more weight loss. Points to know:

• Only one GLP-1 medicine should be taken at a time.
• There is no single conversion chart between medicines. Your prescriber will choose a starting dose for the new medicine based on your current dose, side effects and blood sugar.
• You may restart at a lower dose and titrate again, which can bring a temporary return of side effects.
• Blood sugar may change during the switch, so monitoring is important, especially if you take insulin or a sulfonylurea.

Our guides to switching from Wegovy to Mounjaro and switching from an injection to a tablet explain the principles, although diabetes-specific plans should always come from your diabetes team.

Young people with type 2 diabetes

Type 2 diabetes is increasingly diagnosed in younger people. The UK Mounjaro SmPC now includes children and adolescents aged 10 and above with insufficiently controlled type 2 diabetes. Treatment in children and young people is managed by specialist paediatric diabetes teams. NICE's February 2026 update to NG28, which covers adults, also highlights early-onset type 2 diabetes (diagnosed before 40) as a group in whom earlier use of GLP-1-based treatment may be considered, because of the higher lifetime risk of complications.

Questions to ask your diabetes team

• Where does a GLP-1 medicine fit in my treatment plan under the latest NICE guidance?
• Which GLP-1 medicine would suit me, and why?
• Do any of my current diabetes medicines need reducing or stopping?
• How often should I check my blood sugar, and what readings should prompt me to call you?
• What are my sick day rules?
• When will my eyes, kidneys and HbA1c next be checked?
• If I am also interested in weight-management treatment, am I eligible under NICE criteria?

Remission of type 2 diabetes

Substantial weight loss can lead to remission of type 2 diabetes in some people, particularly those diagnosed recently. This has been demonstrated with low-calorie diet programmes, and the NHS offers a Type 2 Diabetes Path to Remission programme in England for eligible people.

Many people on GLP-1 medicines reach normal or near-normal blood sugar levels. However, remission is usually defined as normal blood sugar levels maintained without glucose-lowering medicines, so improvement while taking a GLP-1 is not usually classed as remission. Discuss your goals with your diabetes team.

Practical tips for people with diabetes starting a GLP-1

• Bring a full medicine list to every appointment, including anything prescribed privately.
• Check your blood sugar as advised, especially if you take insulin or a sulfonylurea.
• Know your sick day rules before you need them.
• Keep up your annual checks, including eye screening, foot checks, kidney tests and HbA1c.
• Eat regular, balanced meals, even if appetite is low, to help keep blood sugar stable. Our guide to what to eat on GLP-1 medication may help.
• Watch for side effects and report them, particularly persistent vomiting.
• Plan ahead for pregnancy if relevant. GLP-1 medicines should not be used in pregnancy. See our guide to GLP-1 medication, pregnancy and fertility.

Our guide to GLP-1 medication interactions covers other medicines that may be affected.

NHS and private routes

Most people with type 2 diabetes receive GLP-1 medicines through their GP practice or diabetes clinic under NG28. Some people also seek weight-management treatment through private providers. If you go down this route, choose a regulated service that asks about your diabetes, other medicines and GP details, and shares information appropriately.

If you are comparing regulated online services, our provider comparison sets out the medical checks each one carries out, and our prices page explains the factors that affect the cost of private treatment. We do not rank providers, and treatment decisions belong to a prescriber.

For more background, see our hubs on weight-loss injections, Mounjaro and oral GLP-1 medicines.

Reporting side effects

You can report any suspected side effect from a GLP-1 medicine, including hypos, eye problems or digestive symptoms, through the MHRA Yellow Card scheme, online or via the app.

When to speak to a professional

Contact your diabetes team, GP or prescriber if:

• You are having more hypos than usual, or your blood sugar readings are much lower or higher than expected
• You have persistent nausea, vomiting or diarrhoea and are not sure which medicines to pause
• You notice changes in your vision
• You are starting a GLP-1 privately and also take diabetes medicines

Call NHS 111 or get urgent advice if:

• You have signs of dehydration, such as dark urine, peeing less often, dizziness or a dry mouth
• You cannot keep fluids down
• Your blood sugar remains very high and you feel unwell, especially if you take an SGLT2 inhibitor

Call 999 or go to A&E if:

• You have a severe hypo with confusion, seizures or loss of consciousness, or someone cannot wake you
• You have severe, persistent abdominal pain, especially if it spreads to your back, with or without vomiting, which may be pancreatitis
• You have sudden loss of vision
• You have yellowing of the skin or eyes (jaundice) with pain or fever
• You are breathing fast, feel very drowsy, have tummy pain and vomiting, or your breath smells fruity, which could indicate a serious diabetes emergency

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