Thinking of switching from 7.5mg Mounjaro to Wegovy?

Why the decision at 7.5mg is more nuanced than a dose conversion

It's a reasonable place to be: you've moved past the starter doses, you're somewhere in the middle of the Mounjaro titration ladder, and you're asking whether the grass is greener on the other side. That uncertainty is completely understandable. The difficulty is that Mounjaro and Wegovy are pharmacologically different medicines, not different strengths of the same drug.

Mounjaro is a dual GIP and GLP-1 receptor agonist, the only medicine of its kind licensed for weight management in the UK. Wegovy activates only the GLP-1 receptor. Because they bind to different targets, their dose scales don't correspond in any straightforward way. A guide to how Mounjaro-to-Wegovy dose conversion works in practice covers this in more detail, but the core point is this: a prescriber can't simply look at 7.5mg and say "that's equivalent to X on Wegovy." They need to assess where you are in your response, your tolerability and your clinical picture before recommending any dose to start Wegovy on.

The table below sets out the factual differences between the two medicines, which is the foundation any honest comparison has to start from. Numbers are drawn from the NICE appraisals for each medicine and the published trial data.

What the evidence actually says when you compare 7.5mg Mounjaro against Wegovy doses

At 7.5mg you are at the midpoint of the Mounjaro schedule. The headline trial figures — around 20–21% average body-weight reduction at 15mg — come from participants who completed the full 72-week titration. That context matters. Someone stable at 7.5mg may still have meaningful dose headroom left on Mounjaro before any switch makes clinical sense.

On the Wegovy side, the picture changed significantly in early 2026. The MHRA approved a 7.2mg semaglutide pen on 14 April 2026, with trial data reporting around 20.7% average weight loss over 72 weeks at that dose. That narrows the head-to-head gap considerably compared with the original 2.4mg data. So the question of how Wegovy and Mounjaro compare overall is genuinely more open than it was two years ago.

What this means practically: if Mounjaro at 7.5mg is working and being tolerated, there is a clinical argument for continuing up the schedule before switching medicines. If there are tolerability issues, or if a particular clinical reason makes Wegovy preferable, a prescriber will assess where on the Wegovy titration you should begin. Starting too high after a switch carries real risk; starting too low when you have established tolerability is also something to discuss. There is no one-size answer here, and pages suggesting a fixed conversion should be read with caution.

Side effects and tolerability: is one medicine easier to manage?

Both medicines share a broadly similar side-effect profile because both slow gastric emptying and act on appetite pathways. The most commonly reported effects are gastrointestinal: nausea, loose stools, constipation, reflux and fatigue. These are most noticeable when starting or moving up a dose, and for many people they settle within a week or two. If they've been significant on Mounjaro, that doesn't automatically mean Wegovy will be easier; the class effect is similar, and the dose you start Wegovy on will influence how the transition feels. If you want to understand more about what 7.5mg Mounjaro looks like when mapped against Wegovy, that page sets out the comparison in detail.

Pancreatitis is a known but infrequent serious risk across GLP-1 and dual-agonist medicines. The MHRA Drug Safety Update of January 2026 highlighted this for the class: severe, persistent stomach pain that may spread to the back, with or without vomiting, needs urgent medical attention. That guidance applies whichever medicine you're taking.

One practical point that comes up in switching conversations: tirzepatide can reduce absorption of oral contraceptives during the first four weeks of treatment and after each dose increase, so a non-oral method is advised alongside the pill during those windows. Switching from Mounjaro to Wegovy doesn't carry the same MHRA-documented interaction, though any change in medicine should prompt a review of all concurrent treatments with your prescriber. Questions about specific combinations are exactly what our prescribers work through at consultation.

How a prescriber approaches a Mounjaro 7.5mg to Wegovy switch request

A prescriber considering this switch will want to know why. Is it because of tolerability problems, availability, cost, a clinical condition that makes one medicine preferable, or something else? The reason shapes everything: which Wegovy dose to start on, whether a wash-out period is appropriate, and how to monitor the transition. Our page on moving from 7.5mg Mounjaro to Wegovy walks through how that clinical conversation typically unfolds.

For readers interested in the specific dose equivalence question, the detail of what Wegovy dose corresponds to 7.5mg of Mounjaro is worth reading alongside this page. A related angle, covered separately, is whether 1mg Wegovy and 7.5mg Mounjaro are equivalent, which addresses one of the most-searched comparisons and explains why the number alone doesn't answer the question.

At nume, our clinical team reviews switch requests with the same rigour as new starts. A GPhC-registered prescriber reads your answers, checks your weight history and current dose, and makes the clinical call. If you'd like to explore your options, check your eligibility through a free consultation and a prescriber will take it from there.