An estimated 1.6 million adults in England, Wales, and Scotland used medications such as Wegovy and Mounjaro to aid weight loss between early 2024 and early 2025, according to a new study from University College London (UCL). The research, published in BMC Medicine and funded by Cancer Research UK, also found that an additional 3.3 million people expressed interest in using weight loss drugs over the following year.
The UCL team analyzed data from a survey of 5,260 adults representative of the general population. Their findings indicate that women were twice as likely as men to use these drugs for weight loss. Usage was most common among people aged 45-55 and those who reported psychological distress in the previous month. While drug use was similar across social groups, future interest was higher among disadvantaged populations where obesity is more prevalent.
Lead author Professor Sarah Jackson of the UCL Institute of Epidemiology & Health Care said: "Our findings show that an estimated 4.9 million adults in Great Britain – nearly one in 10 – have recently used a drug to support weight loss or were interested in using one in the near future.
"This usage far exceeds NHS England's initial goal of prescribing these drugs to 220,000 people over three years.
"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.
"We hope to gather more detailed data in future, monitoring how trends change over time. Good data are important as large numbers of people are taking these drugs outside medical supervision and there is wide potential for misuse. NHS prescribing data only captures a small part of the picture."
Co-author Professor Clare Llewellyn added: "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 study used information from the Smoking Toolkit Study, which surveys different samples each month across England, Wales, and Scotland but does not include Northern Ireland. Questions about weight loss medications were included during January-March 2025.
Participants aged 18 and older were asked about their use of five medications: Mounjaro (tirzepatide), Ozempic, Wegovy, Rybelsus (all containing semaglutide), and Saxenda (liraglutide). Most respondents who took medication solely for weight loss reported using Mounjaro.
Overall, 4.5% had used one of these medications for any reason within the past year; specifically for weight loss, this figure was 2.9%, with another subset (1.7%) using them exclusively for that purpose—equivalent to approximately 910,000 individuals.
Women reported higher rates than men (4% versus 1.7%), with middle-aged adults showing greater prevalence compared to younger or older age groups. Those experiencing moderate or severe psychological distress also showed higher usage rates.
About one in seven users took medication not licensed for weight loss purposes—a practice known as "off-label" use—which researchers note can pose safety risks if done without clinical oversight.
Interest among those who had not previously used such medications was also notable: nearly one in ten women (8.9%) said they would consider taking them within a year compared with just over one in twenty men (5.1%). Interest peaked among those aged 45-55 and individuals reporting recent psychological distress.
Jo Harby, Director of Health Information at Cancer Research UK stated: "As obesity rates rise in the UK, this study shows growing public interest in weight loss medication. While these drugs can aid weight loss, they're not a silver-bullet, as evidence suggests most people regain weight after treatment.
"More research is needed on their long-term impact, how these drugs affect cancer risk, and how best to support people to maintain a healthy weight. These drugs should only be prescribed by healthcare professionals alongside continued care and advice on diet and activity. It's also vital that everyone who needs it can access a range of weight-management support.
"The world around us shapes our health, and the UK Government must do more to create healthier environments for all."
