Wegovy 1.7mg and its Mounjaro equivalent: making sense of the comparison

Why a straight milligram conversion doesn't exist

A question our prescribers hear most weeks is whether a patient on Wegovy 1.7mg can simply move to a specific Mounjaro dose. The honest answer is that the number itself transfers nothing meaningful. Semaglutide and tirzepatide are different molecules acting on different receptor combinations: semaglutide activates GLP-1 receptors only, while tirzepatide activates both GLP-1 and GIP receptors. Because their pharmacology diverges, no fixed conversion ratio exists in clinical guidance, and no regulatory body has published one. You can read more about how the mechanisms differ on our Wegovy vs Mounjaro comparison page.

What clinicians can do is look at where a patient sits within their current titration schedule, how they are tolerating the dose, and what their treatment goals are, then make an informed judgement about an appropriate starting or switching point on the alternative medicine. That is a clinical conversation, not arithmetic.

The Mounjaro equivalent dose to Wegovy question is explored in more detail across our comparison pages, but the short version is consistent: broad functional staging can inform a switch discussion; a precise milligram match cannot.

Where Wegovy 1.7mg sits, and roughly where Mounjaro users are at a similar stage

Wegovy's standard titration runs: 0.25mg → 0.5mg → 1.0mg → 1.7mg → 2.4mg, with roughly four weeks at each level. So 1.7mg is late in the escalation phase, close to maintenance. Most patients are tolerating semaglutide reasonably well by this point, and the full appetite-reducing effect is beginning to consolidate.

On Mounjaro, patients who have been titrating for a comparable period might be anywhere from 5mg to 10mg, depending on how they have tolerated earlier doses and what their prescriber has advised. The 5mg Mounjaro context relative to Wegovy gives a sense of where the lower end of that range sits clinically. Importantly, Mounjaro titration often runs longer than Wegovy's before reaching the higher maintenance doses, partly because six dose levels give prescribers more room to move gradually.

The table below sets out both schedules side by side, with the position of 1.7mg Wegovy marked. Dose conversion considerations are discussed more fully in a dedicated page if you want the fuller picture.

Doses and titration schedules are prescribed individually. The staging above is illustrative; it is not a substitution guide. Source: NHS semaglutide medicine page; NHS tirzepatide medicine page.

What the clinical evidence shows about outcomes at comparable stages

The clearest evidence for a head-to-head comparison comes from the SURMOUNT-5 trial, published in the New England Journal of Medicine in 2025. Across 72 weeks, tirzepatide produced greater average weight reduction than semaglutide 2.4mg in adults with obesity. SURMOUNT-1 reported average body-weight reductions of around 20–21% at 15mg tirzepatide over 72 weeks, while STEP 1 reported roughly 15% average loss with semaglutide 2.4mg over 68 weeks, both versus placebo, in trials with different designs, so direct comparison requires care.

A patient at the 1.7mg Wegovy stage has not yet reached the maintenance dose where most of those trial results were achieved. The gap between 1.7mg and 2.4mg in terms of effect can be meaningful; similarly, a Mounjaro patient at a mid-titration dose has room to increase. This is one reason a prescriber will always want to know not just your current dose but how long you have been on it and how you are tolerating it before discussing any switch.

For a broader look at how costs compare across the two treatments at different dose levels, our tirzepatide vs semaglutide cost page covers that ground. And for background on how the two medicines sit relative to each other more generally, our Wegovy 1.7mg to Mounjaro conversion discussion picks up the practical switching questions.

What actually drives the right decision for you

The choice between Wegovy and Mounjaro (and where to start or switch within either schedule) rests on a handful of things a milligram comparison cannot answer: your weight-loss history, any weight-related health conditions, how your body has responded to treatment so far, your tolerance of GI side effects, practical factors like whether you prefer an injection or (now available in the UK) a tablet, and your prescriber's clinical view of the evidence for your specific situation.

Wegovy 1.7mg being a transition dose rather than a maintenance dose adds another layer: if you are asking this question mid-titration on Wegovy, your prescriber may suggest completing the escalation to 2.4mg before drawing conclusions about switching. If you are exploring options before starting any treatment, the decision looks different again. Our Wegovy 1.7mg equivalent to Mounjaro page and the broader conversion and switching guidance can help frame the questions worth raising.

At nume, a named GPhC-registered prescriber reviews your full picture before any treatment is recommended. You can explore your options and start your free consultation at any point, which medicine, and which dose, is a clinical decision our prescribers make with you.