Prediabetes is a condition where blood sugar levels are higher than normal but not yet high enough to be diagnosed as type 2 diabetes. In the UK, it is often identified by an HbA1c of 42 to 47 mmol/mol (6.0 to 6.4 per cent) or a fasting plasma glucose of 5.5 to 6.9 mmol/L. Approximately 1 in 3 UK adults has prediabetes, and without intervention, approximately 5 to 10 per cent progress to type 2 diabetes each year.

What happens if I stop taking a GLP-1 medication after using it for prediabetes?

Studies suggest that the benefits are at least partially reversed after stopping. In the STEP 1 extension study, participants regained approximately two-thirds of lost weight within a year of stopping semaglutide, and metabolic parameters worsened. For prediabetes specifically, this means the protective effect against diabetes progression likely diminishes once the medication is discontinued, reinforcing the importance of sustained lifestyle changes alongside any pharmacological treatment.

GLP-1 for Prediabetes: Can It Prevent Type 2 Diabetes? UK Guide (2026)

Key facts

Prediabetes prevalence: Approximately 1 in 3 UK adults has prediabetes (HbA1c 42–47 mmol/mol)
Progression risk: Without intervention, 5–10% progress to type 2 diabetes per year
SELECT trial: Semaglutide 2.4 mg weekly reduced diabetes risk by approximately 73% in overweight/obese adults
SCALE Prediabetes: Liraglutide 3.0 mg daily reduced diabetes onset by approximately 79% over 3 years
UK licensing: GLP-1 RAs are not licensed specifically for diabetes prevention; any use for this purpose is off-label
NHS approach: Lifestyle modification (NHS DPP) remains the first-line strategy

Understanding prediabetes

Prediabetes — sometimes called impaired glucose regulation, impaired fasting glucose, or non-diabetic hyperglycaemia — is a metabolic state where blood sugar levels are elevated above normal but below the diagnostic threshold for type 2 diabetes. In the UK, it is typically identified using:

HbA1c: 42–47 mmol/mol (6.0–6.4%) — the most commonly used test in UK primary care
Fasting plasma glucose: 5.5–6.9 mmol/L (impaired fasting glucose)
Oral glucose tolerance test: 2-hour glucose of 7.8–11.0 mmol/L (impaired glucose tolerance)

Prediabetes is extremely common: NHS data suggests approximately 13.6 million people in England are at increased risk of type 2 diabetes. It is strongly associated with excess weight, particularly central (abdominal) obesity, physical inactivity, and family history of diabetes. Certain ethnic backgrounds — including South Asian, Black African, and Black Caribbean — are at higher risk.

Current NHS approach: lifestyle intervention

The NHS Diabetes Prevention Programme (NHS DPP), launched in 2016, is the primary intervention for prediabetes in England. It is a free, evidence-based programme offering:

Group-based sessions over approximately 9 to 12 months
Personalised dietary advice focusing on moderate caloric reduction
Physical activity targets (at least 150 minutes of moderate activity per week)
Behaviour change support and goal-setting
Weight loss target of 5 to 7 per cent of body weight

Evidence from the landmark Diabetes Prevention Programme (DPP) trial in the United States showed that intensive lifestyle intervention reduced diabetes incidence by 58 per cent over approximately 3 years. The NHS DPP has shown real-world effectiveness, though completion rates and long-term weight maintenance remain challenges.

The 7% threshold: Losing approximately 5 to 7 per cent of body weight has consistently been shown to reduce diabetes risk by 50 to 60 per cent in people with prediabetes. For a person weighing 90 kg, this equates to approximately 4.5 to 6.3 kg. GLP-1 RAs typically produce weight loss well in excess of this threshold.

Clinical evidence for GLP-1 RAs in prediabetes

SCALE Prediabetes trial (liraglutide)

The SCALE Obesity and Prediabetes trial randomised over 2,200 adults with prediabetes and obesity (BMI 30 or above, or 27 or above with comorbidities) to liraglutide 3.0 mg daily (Saxenda) or placebo, alongside lifestyle advice. Key findings:

Over 3 years, liraglutide reduced the risk of developing type 2 diabetes by approximately 79 per cent compared with placebo
The time from randomisation to diabetes diagnosis was 2.7 times longer in the liraglutide group
Mean weight loss was approximately 6.1 per cent with liraglutide versus 1.9 per cent with placebo at 3 years
At week 160, more patients in the liraglutide group had reverted to normal glucose tolerance

SELECT trial (semaglutide)

The SELECT cardiovascular outcome trial enrolled over 17,600 adults with established cardiovascular disease, overweight or obesity, but without diabetes. A pre-specified secondary analysis found:

Semaglutide 2.4 mg weekly (Wegovy) reduced the risk of developing type 2 diabetes by approximately 73 per cent over a median 3.3-year follow-up
Among participants with prediabetes at baseline, a significantly greater proportion reverted to normoglycaemia with semaglutide versus placebo
The cardiovascular benefits (20% reduction in major adverse cardiovascular events) add to the overall risk reduction for this population

STEP and SURMOUNT programmes

Although the primary STEP (semaglutide) and SURMOUNT (tirzepatide/Mounjaro) trials focused on weight management, secondary analyses have consistently shown significant improvements in glycaemic parameters among participants with prediabetes. The magnitude of weight loss (15 to 22 per cent in some trials) far exceeds the 5 to 7 per cent threshold associated with diabetes risk reduction.

GLP-1 RAs vs other prevention strategies

Intervention	Diabetes risk reduction	Weight loss	Approximate annual cost
Lifestyle modification (NHS DPP)	~58%	5–7%	Free on NHS
Metformin 850 mg twice daily	~31%	1–3%	£20–40 (generic)
Liraglutide 3.0 mg daily (Saxenda)	~79%	5–8%	£2,400–3,600
Semaglutide 2.4 mg weekly (Wegovy)	~73%	12–17%	£2,700–3,400
Tirzepatide (Mounjaro)	Data emerging	15–22%	£2,400–3,600
Bariatric surgery	~80–90%	25–35%	£8,000–15,000 (one-off)

Off-label use in the UK

Since GLP-1 RAs are not licensed for the specific indication of diabetes prevention, any prescribing for this purpose is off-label. In the UK:

NHS: GLP-1 RAs are not prescribed on the NHS solely for prediabetes. However, if a patient with prediabetes also meets the criteria for Wegovy on the NHS (BMI 35+, or 32.5+ for certain ethnic groups, with a weight-related comorbidity), they may receive it through the weight management pathway. The diabetes prevention effect would be a secondary benefit.
Private: Some private clinics and online prescribers may prescribe GLP-1 RAs for patients with prediabetes who want to reduce their diabetes risk, particularly if they also have obesity. This is legal and not uncommon, but the prescriber must explain that use is off-label.

Practical approach: If you have prediabetes, the most cost-effective and evidence-based first step is lifestyle modification — increased physical activity, improved diet, and achieving 5–7% weight loss. If lifestyle changes alone are insufficient, or if you also have obesity, discussing a GLP-1 RA with your GP or a specialist is reasonable. The combination of lifestyle modification plus a GLP-1 RA is likely more effective than either alone.

Cost-effectiveness debate

The cost-effectiveness of GLP-1 RAs for diabetes prevention is a live debate in health economics:

In favour: Type 2 diabetes costs the NHS approximately £10 billion per year in direct care. Preventing even a fraction of new cases could generate significant long-term savings. The cardiovascular benefits of semaglutide (SELECT trial) add further value.
Against: GLP-1 RAs cost £2,400–3,600 per year per patient. Treating millions of people with prediabetes would be prohibitively expensive. Lifestyle intervention is free and effective for many. Benefits may not persist after stopping the medication.
Middle ground: Targeting GLP-1 RA use to the highest-risk subgroups (e.g., HbA1c 45–47 mmol/mol, BMI 35+, failed lifestyle intervention) could balance efficacy against cost.

NICE has not yet conducted a formal technology appraisal of GLP-1 RAs specifically for diabetes prevention. Any future approval would depend on demonstrating acceptable cost-per-QALY (quality-adjusted life year) ratios within NHS budgets.

What happens when you stop?

A critical question for diabetes prevention is whether the benefits persist after stopping the medication. Evidence suggests they may not fully endure:

In the STEP 1 extension study, participants who stopped semaglutide regained approximately two-thirds of their lost weight within a year, and metabolic improvements partially reversed
In SCALE, after liraglutide was stopped, some participants who had been protected from diabetes subsequently progressed to a diabetes diagnosis
This suggests that, for sustained prevention, either long-term medication use or permanent lifestyle changes (or both) are necessary

Key implication: GLP-1 RAs may delay or prevent type 2 diabetes for as long as they are taken, but they do not cure the underlying metabolic susceptibility. For lasting benefit, the weight loss and lifestyle improvements achieved while on medication need to be maintained after cessation. This is challenging but not impossible with ongoing support.

Frequently asked questions

What is prediabetes?

A condition where blood sugar is elevated above normal but below the type 2 diabetes threshold. In the UK, it is typically identified by an HbA1c of 42–47 mmol/mol. Approximately 1 in 3 UK adults is affected, and 5–10% progress to diabetes each year without intervention.

Can GLP-1 medications prevent type 2 diabetes?

Clinical evidence strongly suggests they can. The SELECT trial showed a 73% risk reduction with semaglutide, and SCALE showed 79% with liraglutide. However, GLP-1 RAs are not yet licensed for this indication in the UK.

Can I get GLP-1 medication on the NHS for prediabetes?

Not specifically for prediabetes. The NHS DPP (lifestyle intervention) is the primary approach. You may qualify for Wegovy on the NHS through the weight management pathway if you also have a BMI of 35+ with comorbidities, which would indirectly help prevent diabetes.

Is metformin or a GLP-1 better for preventing diabetes?

GLP-1 RAs appear more effective (60–80% risk reduction vs ~31% for metformin) and produce more weight loss, but they are far more expensive. Metformin is a reasonable first-line pharmacological option where lifestyle intervention is insufficient, with GLP-1 RAs considered for those who also need significant weight loss or have cardiovascular risk.

What happens if I stop taking a GLP-1 medication?

Benefits are at least partially reversed. Weight regain and worsening of metabolic parameters are common within a year of stopping. Sustained lifestyle changes are essential for long-term diabetes prevention whether or not medication is continued.

Related guides

Sources

NICE — Type 2 diabetes: prevention in people at high risk (PH38)
NHS England — NHS Diabetes Prevention Programme (england.nhs.uk)
le Roux CW et al. SCALE Obesity and Prediabetes: 3 years of liraglutide. Lancet 2017; 389(10077):1399-1409
Lincoff AM et al. SELECT: Semaglutide and Cardiovascular Outcomes. N Engl J Med 2023; 389:2221-2232
Knowler WC et al. DPP: Reduction of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002; 346:393-403
Diabetes UK — Prediabetes risk and prevention (diabetes.org.uk)
BNF — Semaglutide, Liraglutide, Tirzepatide monographs (bnf.nice.org.uk)
Wilding JPH et al. STEP 1 extension: Weight regain after semaglutide withdrawal. Diabetes Obes Metab 2022

GLP-1 forPrediabetes