Results From Mounjaro: What to Expect (October 2026)

01 · The core answer

What results can you expect from Mounjaro?

Weight loss on Mounjaro is gradual by design. The early weeks on 2.5mg are an adjustment phase and losses are usually modest. Most measurable progress builds from 5mg onward, month by month.¹

This table shows the general shape of progress. It is a guide to pattern, not a forecast of your own scales.

For a timeline that applies to GLP-1 medicines generally, see when you start seeing results from GLP-1.

02 · Your next step

Is Mounjaro right for you, and what next?

Mounjaro is a prescription-only medicine. It is supplied only after an online consultation reviewed by a GPhC-registered prescriber, and it is used alongside a reduced-calorie diet and increased physical activity. Individual results vary.

If you have decided to explore treatment, our weight loss clinic explains the options. The Mounjaro pen starts at the 2.5mg dose: your first 2.5mg pen costs £129.99 with code FIRST40 (standard price £169.99). Prices were checked 25 October 2026.

03 · Trial averages

What the SURMOUNT-1 trial found

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.²

These are trial averages. Individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.²

At 72 weeks, 85% of participants on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of their body weight. Half of participants on 10mg and 57% on 15mg lost at least 20% of their body weight.²

A useful way to read this is as a worked example. For someone starting at 100 kg, 20.9% is about 21 kg. That is an average at the top dose after a long period of treatment, not a prediction for any one person, and not a figure for the early months.

04 · Early months

Results in the early weeks and months

Early results are usually modest, and that is normal. In SURMOUNT-1, average weight loss built month by month, with the full 15–21% averages measured at 72 weeks, not 12.² A sensible 3-month expectation on a standard titration is mid single digits as a percentage of body weight, with wide individual variation.²

Some people notice appetite change and early loss in the first week. Others feel little until a higher dose. Both are normal. Early loss includes water weight, so the trend over weeks matters more than any single weigh-in.¹³

Slower early progress does not predict failure, because the dose you respond to may still be ahead of you. Our guide to 2.5mg Mounjaro results covers the starting dose in more detail, and 7.5mg Mounjaro results looks at a mid-range step.

05 · Side effects early on

What feels normal in the first weeks

Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹³ If a symptom is severe, persistent or worrying, speak to your prescriber. Severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of the skin or eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing need immediate medical help: get medical help straight away. You can also report any suspected side effect through the Yellow Card scheme.¹⁹

Our prescribing team provides ongoing monthly reviews, dose-titration and side-effect support, so you are not left to judge progress alone.

06 · Plateaus

When the scales stop moving

Weight loss on Mounjaro is not linear. Plateaus of a few weeks are normal and expected as the body adapts to a lower weight.¹

Within the licence, the sensible responses are:

• Review food intake honestly, because portions drift back up.
• Protect protein and activity.
• Check the basics, such as sleep and alcohol.
• Discuss with your prescriber whether a dose step-up is appropriate if you are not yet at maximum.

A plateau is not a reason to double doses or add unlicensed products.¹

07 · Beyond the scales

Belly fat, waist size and health markers

In trials, weight loss on tirzepatide came with average improvements in waist size, blood pressure, cholesterol and blood-sugar measures, and most participants with prediabetes returned to normal blood-sugar levels.² These are trial-average secondary outcomes, not promises.

A smaller waist was part of the average picture in the trial, but no medicine lets you choose where your body loses weight. These changes are why prescribers talk about weight management as health management rather than appearance.

Your own measures, such as waist, energy and how clothes fit, are worth tracking alongside the scales. Our free companion app, GLPTrackr, is built for tracking a GLP-1 journey.

08 · Fast-loss claims

Celebrity stories and very fast results

Stories about famous people losing weight quickly are not a benchmark for you. They leave out diet, dose, starting point and time on treatment, and they say nothing about what is typical.

Trial data is a better guide, where weight loss built gradually and the averages were measured at 72 weeks. Claims of dramatic weight loss in a few weeks are a red flag, especially from sellers offering to supply without a consultation or prescription. Mounjaro is only genuine when supplied through a regulated pharmacy. You can check ours on the GPhC register (9012878).

For how it compares with other GLP-1 medicines, see Ozempic, Wegovy and Mounjaro results. Ozempic is semaglutide licensed for type 2 diabetes. It is not a UK weight-loss medicine, and prescribing it privately for weight loss is off-label.

09 · Reviews and stopping

Reviewing progress and what happens if you stop

Treatment response is reviewed by your prescriber. If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, your prescriber will discuss whether continuing or stopping is right for you.¹

Tirzepatide has a half-life of about five days, so after a final dose it takes roughly 4–5 weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹ Mounjaro manages weight; it does not cure the biology behind it. In SURMOUNT-4, people who stopped tirzepatide after 36 weeks regained on average 14% of body weight over the following year, while those who continued treatment lost a further 5.5% on average. Stopping should always be planned with your prescriber, with diet and activity habits ready to carry the load. If you are thinking of coming off treatment, read whether you can withdraw from Mounjaro first.

NHS access is also an option for some people. Mounjaro is available on the NHS, but access is being phased in over several years, and the primary-care rollout began in June 2025 with the highest-need groups first.⁶