How many people are on Mounjaro in the UK right now?

How many people take Mounjaro in the UK, and why exact numbers are hard to pin down

No single published register tracks every tirzepatide prescription issued privately in the UK, which is why you'll see a wide range of figures cited in the press. NHS prescription data is published quarterly by NHS Business Services Authority, and those figures will grow as the phased rollout matures, but they cover only NHS-funded scripts, not the private sector. Private prescription volumes are not reported in the same centralised way.

What the data does show is consistent, sharp growth. Mounjaro received its UK weight-management licence in late 2023, and private prescribing expanded quickly as demand outpaced NHS waiting lists. Industry estimates cited by healthcare analysts put the total number of adults in the UK currently on a GLP-1 medicine (including both tirzepatide and semaglutide) in the hundreds of thousands, with tirzepatide's share rising steadily throughout 2024 and 2025. Specific figures for Mounjaro alone are less often broken out, if you see a very precise total quoted without a named source, treat it cautiously.

The NICE recommendation for tirzepatide, published in December 2024, is the structural shift that will most change these numbers over time. You can read the full detail of that recommendation in NICE technology appraisal TA1026. As NHS cohorts expand, the overall population on Mounjaro in the UK will grow in a more trackable, documented way.

Who the people taking Mounjaro actually are, the eligibility picture

The licensed population for Mounjaro is adults with a BMI of 30 or above, or a BMI of 27 or above alongside at least one weight-related health condition. That covers a substantial share of the UK adult population: obesity affects roughly one in four adults in England, and millions more sit in the overweight range with associated conditions. So the pool of people who could, in principle, be suitable is large, which partly explains the speed of uptake.

On the NHS, the criteria are narrower. The current phased rollout, which you can explore in detail on the NHS England weight-management injections page, started with adults carrying a BMI of 40 or above alongside four or more of five specific conditions (high blood pressure, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease or type 2 diabetes). A second cohort opened in June 2026, covering adults with a BMI of 35 to 39.9 meeting the same comorbidity threshold. Lower BMI thresholds apply for certain ethnic backgrounds under UK guidance.

People taking Mounjaro privately often sit just outside the current NHS cohorts (they may have a BMI of 33 with hypertension, for instance) or they prefer not to wait. Both groups count toward the total number on Mounjaro in the UK, which is why any single figure needs a clear source and date attached to it. You can read more about who is taking Mounjaro and the profile of people currently using it.

What growing uptake means for someone deciding whether to start

A large and growing number of people taking Mounjaro is relevant evidence, but it's not the deciding factor for any individual. The more useful questions are whether the clinical evidence applies to your situation and whether the practical route to treatment is safe and legitimate.

On clinical evidence: the SURMOUNT-1 trial (2,539 adults with obesity over 72 weeks) found average body-weight reductions of around 20 to 21% at the 15mg dose. The SURMOUNT-5 head-to-head trial, published in the New England Journal of Medicine in 2025, showed tirzepatide producing greater average weight loss than semaglutide 2.4mg. These are the numbers that matter most for assessing likely effect. Some people respond more strongly than others, and it is worth reading about whether Mounjaro fails to work for certain people before you start, something explored in detail on that page. It's also worth knowing that people can put weight back on after stopping Mounjaro, which is an important part of planning any long-term approach. And if your BMI sits below the standard threshold, our guide to whether Mounjaro is appropriate for slimmer people covers what the evidence and eligibility criteria say in that situation.

On the practical side: because Mounjaro is a prescription-only medicine, the only legal route is a prescription following clinical assessment. The volume of people using it privately has also brought counterfeit pens into circulation, the MHRA has issued repeated warnings and enforcement actions about fake tirzepatide pens sold online without a prescription. Checking any pharmacy on the GPhC register before ordering is the simplest safety check available. For context on how private pricing fits into this picture, our Mounjaro treatment overview covers what to expect at each stage.

If you're still at the stage of exploring options, our weight-loss overview sets out the treatments we prescribe and how they compare. For those ready to take the next step, a free consultation with one of our prescribers is the right place to start, a real clinician reviews your answers the same day, not a queue for automated software.

Start your free consultation and see whether Mounjaro is clinically appropriate for you.