How much weight can you expect to lose on Mounjaro?

Step 1: understand what the trial figures actually mean for you

A common belief is that everyone who starts Mounjaro loses the same amount. That's not quite right. The SURMOUNT-1 trial reported an average reduction of around 20–21% of body weight at the 15 mg dose over 72 weeks, but averages include people who lost considerably more and people who lost less. The trial population had no type 2 diabetes; results in people with diabetes, who are also licensed to use tirzepatide, tend to be somewhat lower on average. You can read a more detailed breakdown of how much weight you can lose on Mounjaro across the full dose range, including what the evidence shows at earlier time points.

Dose matters, too. Someone who reaches 15 mg and tolerates it well is working from a different position to someone who stays at 5 mg because higher doses don't suit them. Our page on weight loss at the 5 mg dose specifically sets out what the data looks like partway up the titration schedule. And because tirzepatide is the medicine in Mounjaro, the same evidence base applies, our page on expected weight loss on tirzepatide gives a pharmacological angle if you want it.

Lifestyle is the multiplier. Mounjaro reduces appetite significantly, but the trial participants also followed a reduced-calorie diet and increased their physical activity. NICE's appraisal of tirzepatide, TA1026, reflects that: the recommendation is for use alongside diet and lifestyle support, not instead of it.

Step 2: know how private pricing fits into this picture

UK private weight-loss treatment with Mounjaro is priced per pen, per month, and prices vary between providers and by dose. Since Eli Lilly raised its UK list price from 1 September 2025, the higher-dose pen's list price rose from around £122 to around £330, and typical private prices across providers now range roughly £149–£375 per month depending on dose and service, as widely reported at the time. Those are market context figures, not an invitation to shop for the cheapest number you can find.

What the headline price often excludes is worth checking. Some services charge separately for the initial consultation, the prescription itself, follow-up clinical reviews, dose-escalation assessments, and delivery. A lower headline can quietly become a higher real cost. Our Mounjaro price guide covers what to look for when comparing providers, and our pen pricing page explains how costs shift across the dose ladder.

At nume, we don't compete on price. One amount covers everything: consultation, prescription, the treatment itself, and free next-working-day delivery by DPD in plain packaging. You can also see how our monthly payment structure works if that framing is useful. We're not the cheapest option available, that's a deliberate choice, not an oversight.

Step 3: weigh clinical safety alongside expected results

For a prescription medicine, the lowest price is the wrong thing to optimise for. Mounjaro is available only with a prescription following clinical assessment; that assessment exists because tirzepatide interacts with other medicines, is not suitable in certain medical histories, and involves a titration schedule that a prescriber manages. Buying from an unverified source (one offering these medicines without a proper prescription process) removes those protections entirely.

The MHRA has warned publicly and repeatedly about counterfeit weight-loss pens, including fake tirzepatide pens produced at an illicit UK site raided in October 2025. Suspected fake medicines or suspect sellers can be reported at the MHRA's Yellow Card scheme. You can verify any online pharmacy on the GPhC register, nume's registration number is 9012878, so you can check us directly. The results you're hoping for require genuine medicine, clinically managed, at a dose your prescriber has approved for you. That's the framework that makes the SURMOUNT figures achievable. Anything that shortcuts it shortcuts the outcome too.

If you'd like to explore the full range of weight-loss treatments we offer, or read more about how the Mounjaro treatment pathway works at nume, both pages are a good starting point before you begin a consultation.