Mounjaro®
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Start journey Learn moreHow the two dosing ladders compare, and why the milligrams don't map neatly
What the trial data shows about 1.7mg Wegovy's position on the semaglutide ladder
Wegovy's titration sequence runs 0.25mg, 0.5mg, 1.0mg, 1.7mg and then 2.4mg maintenance. The 1.7mg dose is a penultimate step, intended to ease patients toward the 2.4mg maintenance dose rather than to serve as a long-term resting point. In the STEP 1 trial, published in the New England Journal of Medicine, participants on semaglutide 2.4mg achieved around 15% average body-weight reduction over 68 weeks, so 1.7mg is the dose most patients pass through briefly on the way to that result. It is worth understanding what 1.7mg of Wegovy is equal to in Mounjaro terms before trying to find an equivalent, because a transitional dose on one medicine does not have a settled therapeutic counterpart on the other.
Mounjaro's six strengths (2.5, 5, 7.5, 10, 12.5 and 15mg) operate on a completely different numerical scale. The 2.5mg pen is a tolerability starter, present to settle the system before treatment begins in earnest. The comparison page covering Wegovy versus Mounjaro sets out the broader picture of how these two medicines differ mechanistically. Briefly: tirzepatide activates both the GLP-1 and GIP receptors, while semaglutide targets GLP-1 alone. That dual action is why the dosing scales are not interchangeable.
For patients mid-titration on semaglutide at 1.7mg, the functional comparison most clinicians consider is the mid-range Mounjaro doses, broadly 5mg to 10mg, depending on how long the patient has been at 1.7mg and their individual response. But that framing is clinical shorthand, not a conversion table, and a prescriber must assess the full picture before any switch.
What the head-to-head evidence says at full maintenance doses
The most robust direct comparison available is the SURMOUNT-5 trial, published in the New England Journal of Medicine in 2025, which randomised 751 adults with obesity and no diabetes to either tirzepatide or semaglutide 2.4mg over 72 weeks. Tirzepatide produced greater average weight reduction. NICE's appraisal of tirzepatide (TA1026) notes that indirect comparisons consistently favour tirzepatide, particularly at its higher maintenance doses. The table below summarises the key evidence-based reference points.
| Reference point | Wegovy (semaglutide) | Mounjaro (tirzepatide) |
|---|---|---|
| Mechanism | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| Maintenance dose | 2.4mg weekly (7.2mg now also approved) | Up to 15mg weekly |
| Average weight loss at maintenance (pivotal trial) | ~15% over 68 weeks (STEP 1, NEJM) | ~20–21% at 15mg over 72 weeks (SURMOUNT-1, NEJM) |
| Titration steps through to maintenance | 5 steps (0.25 → 2.4mg) | 6 steps (2.5 → 15mg) |
| UK licence for weight management | Yes (BMI ≥30, or ≥27 with a weight-related condition) | Yes (BMI ≥30, or ≥27 with a weight-related condition) |
| NICE recommendation | TA875 (specialist services, max 2 years | TA1026) phased NHS rollout, no 2-year cap |
These figures come from separate trials with different populations and durations, so they describe each medicine on its own terms rather than head-to-head performance at a specific dose. The cost comparison between tirzepatide and semaglutide is a separate consideration worth reviewing alongside efficacy.
What this means if you are switching from Wegovy to Mounjaro mid-titration
If you are currently at 1.7mg of Wegovy and considering a switch, the question of what that dose is equivalent to in Mounjaro is understandable but does not resolve the way a unit conversion would. A prescriber reviewing a switch looks at how long you have been at 1.7mg, whether you are tolerating it well, any weight-loss response so far, and your overall health picture. For more on the conversion context, the Mounjaro-to-Wegovy dose conversion page covers the general principles behind cross-medicine dose mapping.
Patients switching from semaglutide to tirzepatide typically restart the titration from Mounjaro's 2.5mg beginning, keeping the pen in the fridge door alongside any other weekly-reminder items, and progressing upward under prescriber guidance rather than jumping to a perceived equivalent dose. This cautious approach reflects the different receptor activity, not a lower potency.
The 1.7mg Wegovy equivalent in Mounjaro question comes up regularly for patients mid-treatment, our prescribers review transfer patients individually, checking evidence of current treatment before any dose decision is made. If you are already on treatment elsewhere and want to discuss a switch, the nume clinical team works through exactly that kind of assessment at consultation. For broader context on starting points, the comparison at the 0.25mg Wegovy level illustrates how differently the two titration ladders begin.
Which medicine, and at what dose, suits you is a clinical decision our prescribers make with you based on your full health picture, not a table.
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