Mounjaro®
Starting from £179.99/mo
Start journey Learn moreHow dose ranges line up across the two treatment schedules, and what that means for switching
Step 1: Understand why a direct dose conversion does not exist
Mounjaro activates two gut-hormone receptors, GIP and GLP-1, while Wegovy targets GLP-1 alone. Because the underlying pharmacology differs, a dose of tirzepatide and a numerically similar dose of semaglutide are not the same thing at all. The titration schedules were also designed independently: Mounjaro runs from 2.5 mg through six steps to 15 mg, while Wegovy (injection) runs from 0.25 mg through four steps to 2.4 mg, or up to 7.2 mg for those on the newer higher-dose pen approved by the MHRA in April 2026. The numbers on the label simply reflect each company's formulation decisions, not any shared scale.
What clinicians do instead is look at therapeutic equivalence: which doses sit at comparable points in each medicine's escalation ladder and produce broadly similar physiological effects. That is an informed clinical judgement, not arithmetic. If you are thinking about how a dose conversion from Mounjaro to Wegovy would work in practice, the short answer is that your prescriber maps where you are in one schedule and decides the most appropriate entry point into the other, usually erring on the cautious side.
Step 2: Read the comparison table — what the trial data shows at each stage
The figures below draw on published trial results and NICE guidance. They are population averages from controlled conditions, not predictions for any individual.
| Mounjaro dose (tirzepatide) | Wegovy dose (semaglutide injection) | Approximate equivalent role in treatment | Average weight loss in trials (at maintenance) |
|---|---|---|---|
| 2.5 mg | 0.25 mg | Starting / tolerability dose | Not a maintenance dose; not a result measure in either trial |
| 5 mg | 0.5–1.0 mg | Early titration | Early-stage data only; both medicines continue to build effect with dose |
| 10 mg | 1.7 mg | Mid-range; some patients maintained here | Clinically meaningful loss reported at both; varies significantly by individual |
| 15 mg | 2.4 mg | Standard maintenance | SURMOUNT-1: ~20–21% average (tirzepatide 15 mg, 72 weeks); STEP 1: ~15% average (semaglutide 2.4 mg, 68 weeks) [Sources: NEJM SURMOUNT-1; NEJM STEP 1] |
| 15 mg | 7.2 mg (approved Apr 2026) | Higher-dose maintenance | Wegovy 7.2 mg trials reported ~20.7% average at 72 weeks, narrowing the gap with tirzepatide 15 mg [Source: MHRA approval, 14 April 2026] |
A note on the 7.2 mg pen: it is licensed for adults with a BMI of 30 or above only, and the dose escalation still begins at 0.25 mg. Jumping straight to 7.2 mg is not how the medicine is prescribed. For a closer look at how the full dose ranges of Wegovy and Mounjaro compare step by step, that page goes through each rung individually.
Step 3: Factor in what changes when you switch between them
Most people reading about equivalent doses are either switching medicines or trying to plan a conversation with a prescriber. A few things matter practically.
First, switching direction matters. Moving from Wegovy to Mounjaro at a seemingly equivalent dose may feel stronger because tirzepatide's dual-receptor action adds an effect semaglutide does not produce. Moving the other way, some patients notice a difference in appetite suppression. Neither observation comes from a large switching trial; SURMOUNT-5 compared the two medicines started fresh, not mid-course. For more detail on the specific Wegovy 1 mg to Mounjaro comparison that often comes up in switching conversations, this page covers that dose pairing in detail.
Second, timing matters more than people expect. If you are switching around a bank holiday or a payday when ordering might be delayed, plan for a possible gap. Running out of either medicine mid-titration and restarting from scratch is something prescribers want to avoid. Third, side-effect profiles overlap heavily (both medicines cause mostly gastrointestinal symptoms, particularly in the first days after a dose increase) but individual tolerance can differ between the two. Your prescriber takes all of this into account before recommending which medicine to try and at what starting point.
If cost is part of your calculation alongside dosing, a direct cost comparison between Wegovy and Mounjaro covers what private treatment at each dose typically costs and what those prices include.
Which medicine is right for you is a clinical call, not a comparison chart
Tables are useful. They are not prescriptions. The SURMOUNT-5 trial showed tirzepatide produced greater average weight reduction than semaglutide 2.4 mg in a head-to-head study, and questions about what 2.4 mg Wegovy is equivalent to in Mounjaro terms are addressed in detail on that page. But averages hide a wide individual spread, and the best-performing medicine on a population chart is not automatically the better fit for your health profile, your other medicines, or how your body responds to GLP-1 or dual-agonist treatment.
Neither Ozempic nor Rybelsus is licensed for weight management in the UK; both are semaglutide, but indicated for type 2 diabetes. The medicines licensed for weight loss are Mounjaro and Wegovy injection, plus the oral Wegovy tablet approved by the MHRA in June 2026 for adults with a BMI of 30 or above. For a fuller overview of how the two main injectables sit against each other on effectiveness, side effects and access, the Wegovy vs Mounjaro comparison page covers all of that ground.
Which dose of which medicine suits you is a decision our prescribers make with you, based on your full clinical picture. Start your free consultation and a GPhC-registered prescriber will review your answers the same day.
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