How Much Do You Need to Weigh for Mounjaro — and What Does It Cost?

You've looked at your BMI, here's what the eligibility picture really looks like

You've probably run the numbers already. Perhaps you're sitting at a BMI of 31 and wondering whether that's enough, or you're at 28 with a GP's note about prediabetes and unsure where you stand. The licensed eligibility criteria for Mounjaro in the UK are set out in the medicine's Summary of Product Characteristics and cover two groups: adults with a BMI of 30 or higher, and adults with a BMI of at least 27 who have one or more weight-related conditions. Those conditions include type 2 diabetes, high blood pressure, dyslipidaemia (raised cholesterol or triglycerides), and obstructive sleep apnoea, among others. BMI thresholds are also adjusted downward by 2.5 kg/m² for people from South Asian, Chinese, Middle Eastern, Black African, or African-Caribbean backgrounds under UK clinical guidance, so the minimum is not identical for everyone.

A question our prescribers hear most weeks is whether a borderline BMI automatically rules someone out. It does not automatically rule them in, either. The prescriber reads the whole picture: current weight, height, health conditions, medications, and anything that might make Mounjaro unsuitable. The NHS BMI calculator at nhs.uk is a practical starting point, and our full eligibility guide goes into detail on what prescribers look for beyond the number itself.

NICE has also published criteria for NHS access to tirzepatide (TA1026), which are stricter, requiring a BMI of 35 or above plus at least one qualifying comorbidity, within a phased rollout. That NHS route is separate from private prescribing, and the licensed criteria above are what govern the private route.

UK private pricing: what the market looks like and what headline figures usually leave out

Private Mounjaro pricing in the UK has shifted significantly. Eli Lilly raised its UK list price from 1 September 2025; reported market prices since then range roughly £149 to £375 per month depending on the dose and the provider. The higher doses carry higher prices, which matters because treatment begins at 2.5mg (a starting dose intended to let your system adjust) and titrates upward over months. The pen you receive at week one is not the pen you'll be on at month six.

Headline prices often quote the entry dose only. What they omit can be significant: separate consultation fees (sometimes £30–£60 per review), prescription charges, delivery costs, and any fees for aftercare messages or dose-change support. A price that looks lower can become comparable, or higher, once those extras are added. There is no regulatory requirement for providers to bundle these, so reading the small print is worth the few minutes it takes. Our Mounjaro pricing page covers what to look for in a quote.

Separately, Mounjaro is a prescription-only medicine. That status matters for price comparisons in a specific way: any supplier offering it without requiring a formal clinical assessment is operating outside UK law. MHRA Drug Safety Updates have documented the risks of counterfeit pens entering the UK (some containing insulin) and have confirmed large enforcement operations targeting illicit supply. A price that sits well below the reported market range is a reason to pause, not celebrate.

Where nume sits on price, and what the single charge covers

Straightforwardly: we are not the cheapest option in the UK private market, and that is a deliberate choice. The price you see on our treatment page covers the consultation, the prescription, the medicine, and free next-working-day tracked delivery, nothing is billed separately afterwards. There is no subscription and no auto-renewal. Every repeat order goes through a fresh clinical review before anything is dispensed.

The clinical infrastructure behind that price includes photo-ID verification, live weight confirmation on video, and GP notification in line with GPhC guidance. A real prescriber reads your answers the same day. If treatment is approved before midday on a working day, it leaves our GPhC-registered pharmacy that afternoon with DPD. You can verify our pharmacy registration (9012878) directly on the GPhC register. That is the transparency we think a prescription medicine warrants.

Curious about how much weight people typically lose on Mounjaro in clinical trials? Our page on Mounjaro weight loss results covers the trial data in full. If you want to explore the broader treatment landscape, our weight-loss treatment overview sets out all the options we offer.

Why 'cheapest' is the wrong question for a prescription medicine

Price is a reasonable thing to care about. But for a prescription-only medicine like Mounjaro, the question that actually protects you is not "which provider charges least?" but "which provider can I verify, and what happens if I have a problem?" Counterfeit tirzepatide pens are a confirmed reality in the UK supply chain. A genuine pen from a licensed pharmacy, dispensed against a real prescription following a real clinical assessment, is categorically different from one sold through social media or via a seller you cannot verify on the GPhC register.

On treatment, practical questions matter too, how much you eat, how to stay hydrated, and how to get enough protein while appetite is suppressed can all affect how well you tolerate titration. Our pages on eating on Mounjaro, hydration guidance, and protein needs on Mounjaro are there when you need them. Our clinical team and FAQs are there for everything else. The right starting point, if you meet the weight criteria and want to explore private treatment, is a free clinical consultation, no commitment, no charge to find out where you stand.