How Much Weight Can You Lose on Mounjaro 5mg?

What the trial data actually tell you about 5mg and weight loss

SURMOUNT-1, published in the New England Journal of Medicine, followed thousands of adults with obesity over 72 weeks. Participants on the highest dose (15mg) lost around 20–21% of their body weight on average. Importantly, the trial was designed to escalate doses over time, so most participants spent relatively little time at 5mg as a steady state; 5mg is a step in the titration sequence, not the treatment ceiling for most people.

At 5mg specifically, individual responses vary considerably. Some people notice noticeable appetite reduction and early weight loss; others are still adjusting to the medicine. The broader evidence on Mounjaro and weight makes clear that results build progressively with dose, the 5mg period is part of a longer journey, and if you want a detailed look at how much you can realistically expect to lose on Mounjaro across the full course, that page sets it out clearly. If you want to understand how the earlier starter dose compares, results on 2.5mg tell a similar story: genuine early losses, but not the full picture.

What the trial numbers cannot tell you is how your body will respond at this particular dose. Factors including your starting weight, how long you spend at 5mg, your diet, and your activity level all matter. That is precisely why a prescriber (not a dosing chart) should be the person guiding these decisions.

The real cost question: what 5mg actually costs you as a private patient

UK private pricing for Mounjaro is set per pen (one pen covers four weekly doses). Since Eli Lilly raised UK list prices from 1 September 2025, typical private market prices across providers have ranged roughly £149–£375 per month depending on dose and supplier, as widely reported. The 5mg pen sits toward the lower end of that range in most private settings.

Here is what those headline figures often leave out: consultation fees, the prescription charge itself, delivery costs, and any ongoing clinical support or dose-review conversations. A quoted price that covers only the medicine (nothing else) can look competitive until you add those items back. A fuller breakdown of what Mounjaro costs in the UK covers this in more detail, including the context around the Lilly price changes that affected the market last year.

If payday falls awkwardly or you're planning around a holiday, it's worth knowing that ordering before 12pm on any working day means dispatch that afternoon, so timing a repeat order isn't complicated once you're established on treatment.

At nume, one price covers the consultation, prescription, the medicine, delivery, and aftercare. We are not the cheapest option available. That is a deliberate choice: the infrastructure required to do this safely (live weight verification, same-day prescriber review, GPhC-registered pharmacy dispensing) costs money to run properly.

Why the lowest price is the wrong thing to optimise for

Mounjaro is a Prescription-Only Medicine. The MHRA has warned publicly about counterfeit tirzepatide pens entering the UK market, fake pens have contained unknown substances, and in 2025 enforcement agencies seized approximately 20 million doses of illegally traded weight-loss medicines worth around £45m. The risk is not theoretical.

When you see a price significantly below the market range, or a seller offering tirzepatide without a clinical assessment, that gap has to be explained by something. It is usually explained by cutting out the prescription process, by unverified supply chains, or by both. For a medicine whose effects on your appetite, blood pressure, and digestion your prescriber needs to monitor, those are not acceptable trade-offs. You can verify any online pharmacy's legitimacy at the GPhC pharmacy register, any legitimate supplier will be listed there.

The question worth asking is not "which provider charges the least for 5mg?" but "which provider will keep me safe and clinically supported as my dose changes?" What you're likely to lose over the full treatment course depends far more on consistent, well-supervised escalation than on the price of any single pen.

How to find out whether 5mg is the right step for you

Whether 5mg is where your treatment starts, where it currently sits, or where your prescriber plans to take you next is a clinical question. Eligibility for Mounjaro requires a BMI of 30 or above, or 27 or above alongside a relevant weight-related condition such as high blood pressure, high cholesterol, or type 2 diabetes. Lower thresholds apply for some ethnic backgrounds under UK guidance. Your prescriber assesses the whole picture, not just the number on the scale.

If you're weighing up Mounjaro against other options, how tirzepatide compares to other treatments is a useful starting point. If you'd simply like to understand how the broader programme works, our treatment overview sets it out plainly. To speak to a prescriber about your own situation, the right place to start is your free consultation, reviewed the same day, with no subscription required and no obligation beyond the clinical conversation itself.