Mounjaro®
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Start journey Learn moreHow 5mg and 7.5mg compare: dose by dose, step by step
Step 1 — where 5mg sits in the licensed treatment sequence
Mounjaro's UK dosing schedule starts at 2.5mg, held for four weeks to let your system adjust. The 5mg dose follows next, again for at least four weeks, and is the first level at which tirzepatide begins to produce the appetite and blood-sugar effects the medicine is actually licensed to deliver. The 5mg pen is therefore a genuine therapeutic step, not a halfway house, but it is still the lower end of the active range. SURMOUNT-1, the phase 3 trial published in the New England Journal of Medicine, tested participants at 5mg, 10mg and 15mg over 72 weeks; 5mg produced an average weight reduction of around 15% from baseline, a result that compares well with earlier single-pathway GLP-1 medicines. That figure matters when considering whether to stay at 5mg or move on.
Clinically, 5mg is also where most GI side effects (nausea, looser stools, reflux) reach their peak and then settle for the majority of people. If they haven't settled by week eight or so, that is information the prescriber weighs before any increase. You can read more about the broader context of Mounjaro's mechanism and schedule on the Mounjaro overview page.
Step 2, what the move to 7.5mg adds
The jump to 7.5mg is the first increase after the tolerability phase is genuinely complete. Tirzepatide is a dual GIP and GLP-1 receptor agonist, as the NHS medicines page for tirzepatide explains, and higher doses intensify activity at both receptors, reducing appetite signals more consistently and slowing gastric emptying further. In practice, people who move to 7.5mg often report a more pronounced reduction in hunger between meals and a lower interest in large portions, effects that support the calorie deficit needed for continued weight loss.
SURMOUNT-1 did not publish a standalone 7.5mg arm (the trial used 5mg, 10mg and 15mg), so the precise average for this specific dose is not available in the same form. NICE's appraisal of tirzepatide (TA1026, published in December 2024) treats the full titration schedule as the licensed approach rather than singling out mid-range doses, reflecting that most patients are expected to continue titrating toward the highest tolerated level. The 7.5mg dose is best understood as a stage in that process, not a destination unless the prescriber decides otherwise. If you are considering the transition from 5mg to 7.5mg specifically, our dedicated page covers what to expect during that change.
Step 3, comparing the two doses side by side
The table below sets out the key factual differences between 5mg and 7.5mg. Numbers from SURMOUNT-1 are cited where available; the 7.5mg row reflects the licensed titration framework rather than a standalone trial arm.
| Factor | Mounjaro 5mg | Mounjaro 7.5mg |
|---|---|---|
| Position in schedule | Weeks 5–8 (after 2.5mg starter) | Weeks 9–12 onward (after 5mg) |
| Average weight reduction at this dose level | ~15% at 72 weeks (SURMOUNT-1, NEJM 2022) | No standalone trial arm; part of the titration continuum toward 15mg |
| Primary clinical role | First active therapeutic dose; GI tolerance still consolidating | First post-tolerability increase; stronger appetite suppression expected |
| Receptor activity | Dual GIP + GLP-1 agonism at moderate intensity | Same dual mechanism at higher intensity |
| Who stays at this dose | Those whose GI side effects have not fully settled, or where clinical review favours a pause | Those who tolerate 5mg well but the prescriber judges 7.5mg the appropriate next step |
| Prescription required | Yes (clinical assessment at every supply | Yes) evidence of current treatment required before increase |
Neither dose is inherently superior; suitability depends on how your body has responded. Our prescribers apply the same principle: the right dose is the one your system tolerates and that is delivering the clinical effect it should. For a detailed look at what 7.5mg involves once you are established on it, the 7.5mg Mounjaro page goes further.
Step 4, the clinical decision and next steps
Dose increases with Mounjaro are not automatic. At nume, every repeat order is reviewed by a prescriber before dispatch; a move from 5mg to 7.5mg requires evidence that you have been on the lower dose, that GI side effects are manageable, and that continuing upward is the right clinical call. This is deliberate. A question our prescribers hear regularly is whether it is possible to extract a higher dose from a lower-strength pen, the short answer is that the pen is calibrated to its stated dose. If you have seen that question circulating, the dedicated page on dosing from a 7.5mg pen explains the mechanics clearly.
When your 7.5mg pen arrives (tracked with DPD, in a plain box with nothing on the outside to indicate what is inside) the pen itself is a pre-filled KwikPen with four doses at 7.5mg each, one per week. Storage is in the fridge, 2–8°C, as with all Mounjaro strengths; the exact room-temperature window if you need to carry it is in the Patient Information Leaflet. If you are still weighing up whether Mounjaro is the right treatment altogether, the treatment options page sets out everything we currently offer. And if you want to understand the comparison between the very first two doses rather than these two, the 2.5mg vs 5mg page covers that ground.
Which of these doses suits you is a clinical decision our prescribers make with you, not something a comparison page can settle. But going into that conversation knowing what the evidence says puts you in a better position to ask the right questions.
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