Mounjaro®
Starting from £179.99/mo
Start journey Learn moreTwo medicines, two dose ladders: what the comparison table shows
The misconception worth clearing up first: 2.4 and 2.5 are not equivalent
The most common confusion here is straightforward: people see two numbers that are almost identical and assume the medicines must be at a similar strength or stage. They are not. Wegovy's dose schedule runs from 0.25mg up to a standard maintenance dose of 2.4mg, so 2.4mg is near the top of the ladder. Mounjaro's schedule starts at 2.5mg and climbs through 5, 7.5, 10, 12.5 and 15mg, so 2.5mg sits at the very bottom. You can read more about how those early dose steps compare across the two medicines on the 0.25mg Wegovy versus 2.5mg Mounjaro page, which covers that specific pairing in detail.
The two medicines also act differently at a pharmacological level. Semaglutide (Wegovy) activates the GLP-1 receptor, slowing gastric emptying and reducing appetite via one hormonal pathway. Tirzepatide (Mounjaro) is a dual agonist: it activates both the GLP-1 and the GIP receptor simultaneously. That dual action is the reason Mounjaro is the only medicine of its kind currently licensed for weight management in the UK. Similar numbers on the pen do not signal similar positioning in treatment.
The full Wegovy vs Mounjaro comparison covers the broader picture (mechanism, trial results, eligibility and cost context) if you want to understand the two medicines side by side rather than dose by dose.
What the trial evidence shows at these specific points in treatment
In the SURMOUNT-1 trial, tirzepatide at its highest dose (15mg) produced an average body-weight reduction of around 20–21% over 72 weeks among adults with obesity and no diabetes, as published in the New England Journal of Medicine. The 2.5mg dose used in the first four weeks is a tolerability step: its job is to let the body adjust before the prescriber moves the dose upward. Expecting therapeutic weight loss at 2.5mg misunderstands what that phase is for.
Wegovy at 2.4mg, by contrast, is the point at which the STEP 1 trial recorded its headline result — around 15% average weight reduction over 68 weeks. That is an established maintenance figure, not a starting point. The SURMOUNT-5 head-to-head trial (published in the NEJM in 2025) found tirzepatide produced greater average weight loss than semaglutide 2.4mg over 72 weeks, though both medicines achieved meaningful results. Comparing 2.4mg Wegovy to 2.5mg Mounjaro in a table makes the numbers look close; comparing them in clinical context reveals they represent entirely different treatment stages.
| Feature | Wegovy 2.4mg (semaglutide) | Mounjaro 2.5mg (tirzepatide) |
|---|---|---|
| Position in dose schedule | Standard maintenance dose (top of the standard ladder) | Starter dose (first 4 weeks only) |
| Mechanism | GLP-1 receptor agonist | Dual GIP + GLP-1 receptor agonist |
| Typical treatment stage | Ongoing weight management | Beginning of titration |
| Average weight loss at this dose | ~15% over 68 weeks (STEP 1, NEJM) | Not a maintenance dose; trial outcomes measured at 15mg |
| UK licence for weight management | Yes (BMI ≥30, or ≥27 with a weight-related condition) | Yes (same criteria) |
A quick habit worth building: if you are ever handed information about either medicine online, check that the pharmacy supplying it is listed on the GPhC pharmacy register. It takes under a minute and confirms the pharmacy is operating legally. If it is not on the register, do not use it.
What this means if you are considering switching or comparing
Patients sometimes ask this question because they are mid-treatment on one medicine and wondering whether the other's numbers suggest a similar or stronger effect at their current stage. The short answer is that dose numbers across different medicines are not portable. A Mounjaro 5mg pen carries a different therapeutic load from a Wegovy 0.5mg pen, even though both are the second step in their respective schedules. The 0.5mg Wegovy and 5mg Mounjaro comparison works through that particular pairing if it is more relevant to where you are in treatment.
Switching between medicines requires a fresh clinical assessment, not a quick dose-number lookup. A prescriber will consider your current weight, how you have responded so far, any side effects, and your overall health picture. The Mounjaro to Wegovy dose conversion page addresses that transition more directly, including what a prescriber weighs up when making the call. If you are further along in your Mounjaro titration and curious how mid-range steps translate, there are dedicated pages exploring whether 1mg Wegovy is the same as 7.5mg Mounjaro and whether 1mg Wegovy is the same as 10mg Mounjaro, both of which unpack those specific pairings in detail. NHS guidance on weight-management injections from NHS England also sets out the clinical context for both medicines.
Which medicine suits you is a clinical decision our prescribers make with you. If you would like that conversation, speak to our prescribers through a free consultation.
Looking to start your weight loss journey?
Take a quick eligibility quiz to explore your options and see how we can support you.