What is 1mg Wegovy Equivalent to in Mounjaro? A UK Dose Comparison

Why can't you convert 1mg of Wegovy into a Mounjaro dose?

The short answer: semaglutide and tirzepatide are different molecules measured in milligrams of their own substance. Wegovy activates one receptor (GLP-1) while Mounjaro activates two, GLP-1 and GIP. Because they bind to different targets with different affinities, the dose that produces a meaningful clinical effect is naturally different for each. Comparing 1mg semaglutide to a number on the Mounjaro scale is a little like comparing 1ml of one liquid to a gram of another: the unit tells you almost nothing without knowing what the substance is and what it does at that concentration.

Wegovy's starting dose is 0.25mg, titrated in stages to 0.5mg, 1mg, 1.7mg and then 2.4mg maintenance, with the newer 7.2mg dose now also approved by the MHRA. Mounjaro starts at 2.5mg and steps through 5mg, 7.5mg, 10mg, 12.5mg and 15mg. Those higher numbers don't indicate a stronger or more aggressive medicine, they simply reflect how tirzepatide is dosed to achieve its effect. You can explore how specific Mounjaro doses relate to Wegovy stages in our Mounjaro equivalent dose to Wegovy guide, which walks through the titration schedules side by side.

This matters practically because patients switching between the two medicines (or arriving at a private clinic having previously used one) sometimes worry that a higher milligram number means a more dramatic dose jump. It usually doesn't. What matters is where you sit in the titration schedule, how long you have been on treatment, and your prescriber's clinical assessment of your response so far.

What does 1mg Wegovy actually represent in the treatment journey?

A 1mg weekly dose of semaglutide (Wegovy) is the third step in the standard titration sequence, it comes after the 0.25mg and 0.5mg phases, each lasting roughly four weeks, and sits below the full maintenance dose of 2.4mg. At this stage the body is still adapting; many people find gastrointestinal side effects have largely settled from the earlier weeks. The 1mg step is meaningful but is not yet the dose at which the STEP 1 trial's headline results (approximately 15% average body weight reduction over 68 weeks) were achieved. Those results were recorded at the 2.4mg maintenance dose, as reported in the STEP 1 trial in the New England Journal of Medicine.

For people curious about what a broadly comparable stage looks like on Mounjaro, the question is less about matching milligrams and more about matching the point in treatment. Our page on Wegovy 1mg and its Mounjaro context looks at this in more detail. The practical takeaway is that both medicines expect patients to titrate gradually, skipping steps to reach a higher dose faster is not recommended and is something a prescriber would advise against.

One quick check worth doing right now: look at your pen's label or the Patient Information Leaflet and confirm the dose number alongside the medicine name. Semaglutide and tirzepatide look similar as pre-filled pens; knowing which molecule you are taking and at what step is the starting point for any meaningful dose conversation with your clinical team.

How do Wegovy and Mounjaro compare on results and mechanism?

Because there is no conversion formula, the more useful comparison is clinical: what do the two medicines achieve, and how do they work? The table below draws on published trial data and NICE guidance.

The SURMOUNT-5 trial is often cited by people trying to decide between the two, but it compared tirzepatide against semaglutide at 2.4mg (not at 1mg) so it does not directly answer the question of how 1mg Wegovy sits relative to any Mounjaro dose. Our broader Wegovy vs Mounjaro comparison covers the full evidence picture, and our cost comparison for the UK breaks down what each typically costs privately. You can also read about whether Wegovy has a particular dose that tends to drive the most change in our page on Wegovy's golden dose.

Which medicine is right for you, and how does a prescriber decide?

A prescriber looks at far more than a dose number. Your current weight and BMI, any conditions such as type 2 diabetes or cardiovascular disease, how you have tolerated previous treatments, your preferences around injection frequency and device type, and any medicines that might interact, all of these feed into the clinical picture. Oral contraceptive users, for example, are advised to add a barrier method during the first four weeks of tirzepatide and after each dose increase, because absorption of the pill may be reduced; NHS England's guidance on weight management injections covers this clearly. Semaglutide does not carry the same documented interaction.

Neither medicine is right for everyone. Pregnancy, breastfeeding, a history of medullary thyroid carcinoma or MEN2, and certain gastrointestinal conditions all require careful prescriber discussion. Under-18s are not covered by either licence. The MHRA also flagged acute pancreatitis as a known infrequent risk for GLP-1 medicines, severe, persistent stomach pain reaching the back is a reason to seek urgent medical help.

Our prescribers review every consultation individually, the clinical team page gives you a sense of who that is. If you are weighing up the two medicines or considering switching, the Mounjaro to Wegovy dose conversion page and the Wegovy 2.4mg equivalent page add further context. Ultimately, which medicine suits you (and at what dose) is a clinical decision made with your prescriber, not something a dose chart alone can answer. Start your free consultation and our prescribers will assess both options with you.