How many Mounjaro pens do you need per month — and what does that mean for cost?

One pen, one month: the simple part

The maths is straightforward. Mounjaro is a once-weekly injection, and each KwikPen holds exactly four doses. One pen covers four weeks. So whether you are at 2.5mg, 10mg or the maximum 15mg, your monthly requirement stays the same: one pen, four injections. What changes as treatment progresses is the strength of that pen, which is why the cost question doesn't have a single lifetime answer.

The licensed schedule (2.5mg to start, typically stepping up every four weeks at the prescriber's discretion) means most people work through several dose tiers over the course of treatment. You can read more about what each pen contains and how the doses work on a dedicated page, but the key practical point is this: budget for your current dose, and revisit the figure each time your prescription is reviewed.

Mounjaro (tirzepatide) is the only dual GIP and GLP-1 receptor agonist licensed for weight management in the UK. That distinction matters clinically, and it also matters when you are comparing prices across providers, because you need to be certain the product, the dose and the prescribing process are equivalent before the numbers mean anything.

What headline monthly prices often leave out

If you have been searching for Mounjaro prices online, you have probably noticed a wide range of figures. Some of that variation reflects genuine differences in dose: a 2.5mg starter pen costs less than a 15mg maintenance pen. But some of it reflects what the advertised price does and does not include.

Prescription fees are sometimes charged separately. Consultation fees (covering the clinical assessment that the law requires before any prescription is issued) may or may not be bundled. Delivery charges, aftercare support and the cost of follow-up reviews before dose increases are all things worth asking about before you commit. A figure that looks low at first glance can climb once those line items appear. The full picture of monthly Mounjaro costs is worth working through carefully.

We understand that the range of prices out there can feel baffling, especially when you are trying to plan a treatment course that may last many months. That frustration is completely reasonable. The aim of this page is to give you the clearest possible framework for thinking about it.

How nume prices this, honestly

One transparent price. That covers your consultation, your prescription, your treatment and free next-working-day delivery by DPD in plain unbranded packaging. No extras at checkout. No recurring charge you didn't agree to. The current price by dose is shown on our treatment page.

We are not the cheapest provider. That is a deliberate decision. We run no discount codes, no promotional offers and no voucher schemes, partly because the law prohibits advertising prescription medicines to the public through incentives, and partly because we think a service built around speed, clinical rigour and genuine aftercare is worth pricing honestly. You can explore how Mounjaro is priced per month and what drives those costs across the market, but the short version of our position is that we'd rather tell you plainly what you get than compete on a number that strips the service out.

Every consultation at nume is personally reviewed by a GPhC-registered Independent Prescriber. You can verify our pharmacy on the GPhC register (premises number 9012878). There are no algorithms making clinical decisions here.

Why price is the wrong starting question for a prescription medicine

For a prescription-only medicine dispensed through a regulated supply chain, the cheapest listing is answering the wrong question. The right questions are: is the pharmacy GPhC-registered and verifiable? Is a qualified prescriber reviewing your case before every supply? Is the medicine coming from the licensed UK supply chain?

The MHRA has warned repeatedly about fake weight-loss pens sold through social media and unofficial websites. In October 2025, enforcement teams raided the first UK site found to be manufacturing counterfeit tirzepatide pens. Large seizures of fake products have been made across 2024 and 2025. If a price looks dramatically low, or a seller is offering these medicines without a full clinical assessment, those are serious red flags. You can report suspect sellers directly at the MHRA Yellow Card site.

NICE's appraisal of tirzepatide (TA1026) sets out the clinical evidence base for this medicine, and the Mounjaro price guide on our site places private costs in their proper context. The SURMOUNT-1 trial, published in the New England Journal of Medicine, reported an average body-weight reduction of around 20–21% at the 15mg dose over 72 weeks, results that came from a controlled clinical programme with full prescriber oversight. Replicating that environment privately means choosing a service that takes the clinical side as seriously as the logistics. Explore our weight-loss treatment options or speak to our prescribers to find out whether Mounjaro is right for you.