Have Mounjaro sales gone down — and what does the evidence say?

What the licensing and prescribing data actually show

The short answer to the question is: no, Mounjaro sales have not declined across the UK market taken as a whole. The trajectory since Eli Lilly received MHRA approval for tirzepatide in the weight-management indication has been upward. NICE's appraisal, published on 23 December 2024 and updated in September 2025, recommended tirzepatide for adults with a BMI of 35 or above alongside at least one weight-related comorbidity, and a lower threshold applies for several ethnic-background groups under NICE's tirzepatide guidance (TA1026). That recommendation opened an NHS access route and generated a new wave of clinical interest that prescription data reflect.

The trial evidence underpinning that recommendation is worth stating plainly. In SURMOUNT-1, involving thousands of adults with obesity, participants taking the 15mg dose lost an average of around 20–21% of body weight over 72 weeks. Those figures, published in the New England Journal of Medicine, helped convince NICE the medicine offered substantial clinical benefit. Demand in their wake has been substantial too.

The misconception worth addressing: some people assume the Lilly price increase or tighter enforcement means Mounjaro has become harder to obtain or less popular. Neither is quite right. The enforcement story is about counterfeits leaving the market; legitimate prescriptions have continued to grow, and you can see how that picture has developed on our tirzepatide sales trends page.

The September 2025 price change and its effect on the private market

What did shift noticeably was the private-market price. Eli Lilly raised the UK list price of Mounjaro from around £122 to around £330 per four-week pen at the highest dose, effective 1 September 2025, a change widely reported at the time. Typical private prices since then range roughly £149–£375 per month depending on dose and provider. You can find more context on how those figures break down on our Mounjaro cost page.

The practical effect was that some people paused treatment or reconsidered starting, and some providers adjusted their offering. But that is distinct from overall prescribing volume falling. It reflects a market recalibrating around a higher price point. People who had been accessing tirzepatide primarily on price found that calculation changed; people accessing it for clinical reasons continued.

It also reinforced a point that prescribers make regularly: for a prescription medicine, price is not the right measure of value. Clinical supervision, genuine supply-chain assurance, and consistent access to the right dose matter more to outcomes than finding the lowest listing.

MHRA enforcement and what it tells us about the counterfeit landscape

Through 2025 the MHRA significantly escalated its action against illegally traded weight-loss medicines. Around 20 million doses with an estimated street value of roughly £45 million were seized, and in October 2025 enforcement teams raided what the MHRA described as the first illicit UK site manufacturing counterfeit tirzepatide pens, in Northampton. These are fake pens: they do not contain genuine tirzepatide, and previous MHRA warnings have documented cases where counterfeit pens contained insulin instead, which raises serious safety concerns including risks that some patients have compared to the fluid-retention effects discussed on our tirzepatide diuretic page. You can report a suspect seller or a suspected fake product via the MHRA's Yellow Card scheme.

None of this activity represents a drop in legitimate Mounjaro prescribing. It represents regulators removing unsafe product from an informal grey market that had grown alongside the legitimate one. The parallel story is that the factors sometimes described as causing a sales drop mostly reflect noise in informal resale channels, not in pharmacy dispensing records.

Any pharmacy dispensing Mounjaro legitimately can be verified on the GPhC register at pharmacyregulation.org/registers. Sellers offering tirzepatide without a formal prescription process are a red flag regardless of price.

What this means if you are considering tirzepatide now

Demand remains high and genuine supply runs through the licensed UK supply chain. If you are wondering whether this is still a realistic option, yes, it is, through a registered prescriber following a clinical assessment. The NHS route via TA1026 is expanding in phases; from around June 2026, Cohort 2 (BMI 35–39.9 with four or more qualifying conditions) became eligible. Private prescribing through a regulated pharmacy remains an option for people who do not meet the NHS criteria or prefer not to wait.

For more on how tirzepatide works and who it is licensed for, our tirzepatide overview covers the mechanism, the evidence, and the eligibility picture in full. If you want to understand the broader sales context, the Mounjaro prescribing trends page goes deeper into the data. And for people ready to find out whether treatment could be right for them, a conversation with a clinical prescriber is the right first step.

Our prescribers at nume review every consultation personally, a real clinician reads your answers the same day, not software. If you are clinically suitable and order before noon on a working day, treatment is dispatched that afternoon and arrives free by DPD the next working day. Start your free consultation to see whether you qualify.