Mounjaro®
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Start journey Learn moreHow Wegovy 1mg Fits Into the Semaglutide Ladder, and Where Mounjaro Sits Alongside It
What the trial data actually shows at 1mg semaglutide and the nearest Mounjaro steps
To understand what Wegovy 1mg is equivalent to in Mounjaro, it helps to anchor both medicines in their clinical evidence. Wegovy's titration path runs 0.25mg, 0.5mg, 1mg and 1.7mg before the 2.4mg maintenance dose, so 1mg is still a stepping-stone, not the dose that produced the headline STEP 1 trial result of around 15% average body-weight reduction over 68 weeks, as published in the STEP 1 paper in the New England Journal of Medicine. Mounjaro's comparable mid-titration doses are 5mg and 7.5mg, with treatment starting at 2.5mg and climbing toward a 15mg ceiling. The SURMOUNT-1 trial, which involved 2,539 adults with obesity, recorded an average weight reduction of around 20–21% at the 15mg maintenance dose, again, a maintenance figure, not a mid-titration one. Neither 1mg Wegovy nor 5mg Mounjaro is intended to be the dose someone stays on; both exist to let the body adjust before the next step, and if you want to explore how those two doses compare in more detail, our page on Mounjaro 5mg and its relationship to Wegovy sets out the evidence behind that particular step. A fuller head-to-head comparison of Wegovy and Mounjaro sets out how those maintenance results stack up against each other.
The honest answer to "what is 1mg Wegovy equivalent to in Mounjaro" is therefore this: at a biological-mechanism level, 1mg semaglutide and approximately 5mg tirzepatide both represent an early-to-mid titration stage. Neither is the medicine at full working strength. Prescribers do not use a conversion table, they consider the full clinical picture.
Why the two dose ladders do not convert neatly into each other
Semaglutide (Wegovy) is a GLP-1 receptor agonist; tirzepatide (Mounjaro) is a dual GIP and GLP-1 receptor agonist, the only medicine of its kind licensed in the UK for weight management. Activating two pathways instead of one means the underlying biology is different, so milligram figures from one drug cannot be transposed onto the other the way you might convert paracetamol to ibuprofen. The doses are not measured on a shared scale.
This matters practically. If someone is switching between Wegovy and Mounjaro (whether because of supply, tolerability, or a clinical decision) the prescriber sets the starting Mounjaro dose based on the patient's history, not by looking for the numerically closest number. Our guide to Mounjaro-to-Wegovy dose conversion explains how prescribers approach a switch in either direction, and why the answer is rarely a straight numerical match. The NICE appraisal of tirzepatide (TA1026) and the corresponding appraisal of semaglutide (TA875) each set out the evidence on which UK licences are based, worth reading if you want to see the regulatory reasoning behind each medicine.
Storage gives a small practical illustration of how differently these two medicines work in daily life. Wegovy pens need to live in the fridge (the door shelf is fine), whereas taking them out briefly for injection is straightforward. Both have a limited room-temperature window; the exact details are in each medicine's Patient Information Leaflet, and that leaflet, not a website, is where to check.
Dose comparison at a glance, what the data supports
The table below sets out factual information from the licensed dose schedules and published trial evidence. It is not a conversion guide and should not be used as one.
| Feature | Wegovy (semaglutide) | Mounjaro (tirzepatide) |
|---|---|---|
| Mechanism | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| Starting dose | 0.25mg weekly | 2.5mg weekly |
| 1mg sits at | Third rung of five titration steps | Not a licensed Mounjaro dose |
| Maintenance dose | 2.4mg weekly (7.2mg also approved) | 15mg weekly (lower doses may be the highest tolerated) |
| Average weight loss at maintenance (trial) | ~15% over 68 weeks (STEP 1, NEJM) | ~20–21% over 72 weeks at 15mg (SURMOUNT-1, NEJM) |
| Head-to-head evidence | SURMOUNT-5 (NEJM 2025): tirzepatide produced greater average weight loss than semaglutide 2.4mg over 72 weeks in adults with obesity and no diabetes | |
For context on how the higher Mounjaro doses compare to maintenance Wegovy, our page on Mounjaro 15mg and Wegovy goes into more detail. For the middle of the schedule, a look at 10mg Mounjaro alongside Wegovy doses may be useful.
What this means if you are considering treatment
The question of what 1mg Wegovy is equivalent to in Mounjaro terms is one our prescribers hear regularly, usually from people who are switching, comparing options, or trying to make sense of a friend's experience on a different medicine. That curiosity is completely reasonable. The honest answer is that no conversion table exists, and the two drugs are not interchangeable by dose.
What a prescriber can do is look at your full picture: your BMI, any weight-related health conditions, how you have responded to treatment before, and which medicine's profile fits your circumstances. Both Wegovy and Mounjaro are licensed in the UK for weight management in adults with a BMI of 30 or above, or 27 or above with at least one relevant health condition. Both are prescription-only. An overview of the weight-loss treatments available at nume covers both medicines in plain terms, and a cost comparison between Wegovy and Mounjaro addresses what each typically costs privately. Which suits you is a clinical decision our prescribers make with you, not something a comparison chart can settle. Start your free consultation to have a prescriber review your situation the same day.
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