Nearly 1 in 10 adults in Great Britain have used a GLP-1 weight-loss medication or are interested in using one in the near future, according to a nationally representative survey published in BMC Medicine. The estimate, drawn from a household poll of 5,260 adults in England, Scotland and Wales, lands at approximately 4.9 million people.
The figure far exceeds NHS England’s phased roll-out, which plans to provide the drugs to 220,000 people between 2025 and 2028. Researchers at University College London, who ran the study, frame the gap between NHS supply and private demand as a question of who is actually accessing the jabs.
4.9 Million Touch the GLP-1 Market
The headline figure combines two groups: the 1.6 million adults who said they had used a GLP-1 or dual GLP-1/GIP medication to support weight loss in the past year, and the 3.3 million who had not used such drugs but said they would be likely or very likely to consider doing so in the next year. An additional 910,000 adults used the medications exclusively for weight loss, with no other medical reason such as type 2 diabetes.
The team relied on data from the Smoking and Alcohol Toolkit Study, a monthly cross-sectional survey that interviews a new sample of roughly 2,450 adults representative of Great Britain each month. The GLP-1 questions ran across three consecutive months, January through March 2025, capturing a single point in time as use climbed. The study was funded by Cancer Research UK and published in BMC Medicine in 2026, and its DOI is 10.1186/s12916-025-04528-7.
Key figures from the survey, with confidence intervals as printed by the authors:
- 4.5% of adults used a GLP-1 or GLP-1/GIP drug in the past year for any reason
- 2.9% (95% CI 2.4 to 3.4) used for weight loss, equal to about 1.6 million adults
- 1.7% (95% CI 1.4 to 2.1) used exclusively for weight loss, about 910,000 adults
- 6.5% (95% CI 5.7 to 7.3) of non-users would consider using in the next year, about 3.3 million adults
Who’s Already Taking the Jabs
Use was not evenly spread. Among survey participants, 4% of women reported using a GLP-1 or GLP-1/GIP drug for weight loss in the past year, against 1.7% of men. Middle-aged adults were the heaviest users: 4.2% of those aged 45 to 55 said they had taken a GLP-1 medication for weight loss, compared with 1.2% of 18-year-olds and 1.5% of 75-year-olds.
Mental health also tracked closely. Among adults who reported moderate or severe psychological distress in the past month, 3.7% had used a GLP-1 or GLP-1/GIP drug for weight loss, against 2.4% among those reporting no or low distress. Researchers say this pattern is consistent with the well-established two-way relationship between obesity and mental health. About 85% of those who used the medications for weight management in the past year reported taking products licensed for weight loss in Great Britain. Among those who used them exclusively for weight loss, that share rose to 91.4%.
The Next Wave of Demand
Among adults who had not used a weight-loss medication in the past year, 6.5% said they would consider doing so in the next year. The profile of this waiting room mirrors the user base in some respects but diverges sharply in others. Interest was higher among women than men, and highest among those aged 45 to 55.
It also ran higher among adults reporting moderate or severe psychological distress in the past month, at 10%, compared with 5.2% among those with no or low distress.
Use and interest by group, as reported in the survey:
| Group | Used for weight loss in past year | Interested in using in next year |
|---|---|---|
| Women | 4% | 8.9% |
| Men | 1.7% | 5.1% |
| Aged 45 to 55 | 4.2% | 9.7% |
| Moderate or severe psychological distress | 3.7% | 10.0% |
| No or low psychological distress | 2.4% | 5.2% |
Interest was also higher among adults experiencing greater financial hardship or those not in paid work because of long-term illness or disability. Use was similar across these groups.
Mounjaro Leads the Field
Five GLP-1 or GLP-1/GIP medications were included in the survey: Mounjaro, which contains tirzepatide, Ozempic, Wegovy and Rybelsus, which contain semaglutide, and Saxenda, which contains liraglutide. Three of those, Saxenda, Wegovy and Mounjaro, are licensed specifically for weight loss in the UK by the Medicines and Healthcare products Regulatory Agency. Mounjaro also mimics a second hormone called GIP that helps regulate blood sugar, on top of its appetite-suppressing effect.
Among respondents who used GLP-1 or GLP-1/GIP medications exclusively for weight loss, the most commonly reported product was Mounjaro at 80.2% of users (95% CI 71.9 to 88.6). A clinical nutritionist has warned that side effects of weight loss jabs such as hair loss and muscle loss are being dangerously ignored, with almost 2 million people in the UK now using the injections.
A £200-a-Month Access Gap
The study surfaces a structural mismatch between NHS supply and private demand. NHS England’s phased roll-out plans to provide the drugs to 220,000 people between 2025 and 2028, and clinical guidance from NICE restricts NHS prescribing to patients with at least one weight-related comorbidity and a BMI of 35 or above, or 30 for semaglutide under stricter criteria. The study cites modelling that estimates 3.4 million adults in England are eligible on these terms.
The market outside the NHS is much larger. Mounjaro, the most popular drug in the survey, typically costs around £200 a month when bought privately, an amount that puts it out of reach for many of the adults who told pollsters they would consider using it.
Interest in future use was greater among adults facing greater financial hardship. It was also higher among those out of paid work because of long-term illness or disability. Use among the same socioeconomic groups was similar, leaving interest unmatched by current NHS access.
A December 2024 poll of 2,161 UK adults found 22% would use a GLP-1 weight-loss drug if available on NHS prescription, against 8% who would pay for it privately. In the current UCL survey, 4.5% of adults are taking these drugs for any reason and 2.9% for weight loss.
On the equity question, co-author Professor Clare Llewellyn, of UCL, said:
Weight-loss drugs like GLP-1 agonists could play an important role in improving the health of the nation. Our findings suggest many people are accessing these medications outside the NHS. This raises concerns about equity given the costs of these drugs, as well as the adequacy of supervision of treatment.
The Off-Label Shadow
The survey also documented a quieter concern. Among adults who used GLP-1 or GLP-1/GIP medications for weight loss, 15% (about one in seven) reported taking products not licensed for weight loss in Great Britain, such as Rybelsus, which is licensed in the UK for type 2 diabetes only.
The figure could reflect off-label prescribing by clinicians or access through non-medical channels. The survey did not collect enough information to determine how these medications were obtained or whether their use met licensed indications. Researchers caution that using drugs off-label can pose safety risks, particularly when accessed without appropriate clinical supervision.
Gastrointestinal side effects such as nausea, vomiting, diarrhoea and constipation are common with GLP-1 medications, the paper notes, and serious adverse effects including pancreatitis have been reported. With many adults accessing the drugs outside NHS oversight, traditional prescribing data sources cannot be relied on to capture the full picture.
What the Numbers Don’t Show
The authors stress that the study draws on self-reported, cross-sectional survey data and cannot establish whether factors such as psychological distress or socioeconomic circumstances directly influence medication use or interest. Respondents were not asked about their BMI or specific health conditions, so the survey cannot tell how far demand reflects genuine medical need. The team also cannot say how often people of a healthy weight are using the drugs unnecessarily.
The researchers note that the data cannot determine whether the relationships they observed are causal, only that they co-occur in the survey. Further population-level monitoring will be important, they write, to guide healthcare policy and ensure these medications deliver sustainable benefits without widening health inequalities.
Lead author Jackson said the team hopes to gather more detailed data in future, monitoring how trends change over time:
We do not know about our survey respondents’ BMI or health conditions, so it is not clear how far this reflects a genuine medical need or how often the drugs are used unnecessarily by people of a healthy weight. Good data are important as large numbers of people are taking these drugs outside medical supervision and there is wide potential for misuse.
Jo Harby, director of health information at Cancer Research UK, which funded the study, said the long-term picture is unsettled. She noted that evidence suggests most people regain weight after treatment, and called for more research into how the drugs affect cancer risk and how best to support people to maintain a healthy weight.
Frequently Asked Questions
How many people in the UK use weight-loss drugs?
An estimated 1.6 million adults in Great Britain reported using a GLP-1 or GLP-1/GIP medication to support weight loss in the past year, according to the UCL survey published in BMC Medicine. An additional 3.3 million said they would consider using one in the next year.
Which weight-loss drug is most popular?
Mounjaro (tirzepatide) was the most commonly reported medication among people using GLP-1 or GLP-1/GIP drugs exclusively for weight loss, used by 80.2% of that group. It was followed by Wegovy and Saxenda, the three products licensed for weight loss in the UK.
How much do weight-loss jabs cost privately?
Mounjaro, the market leader, typically costs around £200 a month when bought privately, according to figures cited by the UCL research team. NHS prescriptions are tightly restricted by NICE eligibility criteria.
Who is most interested in using weight-loss drugs?
Interest was highest among women (8.9%), adults aged 45 to 55 (9.7%), and people reporting moderate or severe psychological distress in the past month (10%). Interest was also higher among adults experiencing financial hardship or not in paid work due to long-term illness.
What is off-label weight-loss drug use?
The UCL survey found that 15% of adults who used GLP-1 or GLP-1/GIP medications for weight loss were taking products not licensed for that purpose in the UK, such as Rybelsus, which is licensed only for type 2 diabetes. Researchers caution that off-label use outside medical supervision can pose safety risks.
