Is 1mg Wegovy the Same as 7.5mg Mounjaro? What the Evidence Actually Shows

Different medicines, different receptors: why the numbers aren't comparable on their own

Wegovy's active ingredient is semaglutide, a GLP-1 receptor agonist. It works by mimicking a single gut hormone involved in appetite regulation and gastric emptying. Mounjaro's active ingredient is tirzepatide, which activates both the GLP-1 and GIP receptors simultaneously, the only dual-agonist weight-loss medicine licensed in the UK. Because the underlying mechanisms differ, comparing a milligram figure across the two medicines is a bit like comparing the voltage rating on two different types of battery: the number describes something real, but it doesn't tell you what the two things will actually do.

The NHS medicines information for semaglutide and tirzepatide both note these distinct mechanisms, and neither product's prescribing information provides a direct dose-equivalence table for switching between them. That absence is itself informative: there is no officially validated conversion.

If you're curious how other dose pairings across the two medicines are discussed, the Mounjaro-to-Wegovy dose conversion page covers the general landscape of that question in more detail.

Where 1mg Wegovy and 7.5mg Mounjaro sit on their own schedules

Context matters here. Wegovy's titration runs from 0.25mg through 0.5mg, 1.0mg, 1.7mg and up to 2.4mg, or 7.2mg for those who reach the higher-dose pen approved by the MHRA in April 2026. The 1mg dose is the third rung of that ladder: it is a mid-titration step, not a maintenance dose. Most people move through it on the way to 1.7mg and then 2.4mg. It is not where the headline trial results were measured.

Mounjaro runs from 2.5mg up through 5, 7.5, 10, 12.5 and 15mg. The 2.5mg pen exists purely to give the body time to adjust before any real therapeutic work begins. By 7.5mg, a patient is mid-range on Mounjaro's schedule, past the starter phase and into territory where meaningful clinical effect is typically being seen, though the highest average reductions in the SURMOUNT-1 trial were recorded at 15mg.

So: 1mg Wegovy is below the maintenance dose for semaglutide; 7.5mg Mounjaro is a mid-range therapeutic dose for tirzepatide. They occupy very different positions relative to their own clinical endpoints. A separate page covers which Wegovy dose is closest in effect to 7.5mg Mounjaro if that is the specific question you are working through.

What the trial data shows, and what it doesn't resolve

The SURMOUNT-1 trial, published in the New England Journal of Medicine, found average body-weight reductions of around 20–21% at tirzepatide 15mg over 72 weeks in adults without diabetes. The STEP 1 trial, also published in the New England Journal of Medicine, found roughly 15% average reduction with semaglutide 2.4mg over 68 weeks. The SURMOUNT-5 trial, a head-to-head published in the NEJM in 2025, found tirzepatide produced greater average weight loss than semaglutide 2.4mg across a 72-week period. NICE's appraisal of tirzepatide (TA1026) notes that indirect comparisons in the evidence also favour tirzepatide.

None of these trials compared 1mg semaglutide with 7.5mg tirzepatide specifically. The headline numbers above reflect maximum maintenance doses; results at lower or mid-titration doses are typically more modest and not the primary endpoints the appraisals rely on. A quick check worth doing: pull up the NHS pages for each medicine and look at the dosing section, it takes about 45 seconds and gives you a clear picture of where any given dose sits on its own ladder before drawing comparisons across them.

For a broader side-by-side look at the two medicines at their licensed maintenance doses, the Wegovy vs Mounjaro comparison covers the full picture, and the cost comparison between tirzepatide and semaglutide is useful if price is part of your thinking.

What this means if you're considering switching or starting

The comparison in this keyword (1mg Wegovy against 7.5mg Mounjaro) tends to come up in two situations. Either someone is mid-titration on Wegovy and wondering whether they would be further along on Mounjaro, or someone is reviewing a dose conversion before a potential switch. Both are legitimate clinical questions. Neither has a clean arithmetic answer.

What a prescriber can do is look at your weight, your response so far, any side effects, and your other health factors, then give you a grounded view on whether continuing titration on the current medicine, or starting afresh on the other, makes more sense for you. The weight-loss treatment overview sets out both options in plain terms, and our clinical team reviews every consultation personally before any treatment is issued.

Other dose-level comparisons that patients often find useful alongside this one include whether 0.5mg Wegovy is equivalent to 5mg Mounjaro and how 1mg Wegovy compares to 10mg Mounjaro.

Which medicine, and which dose, suits you is a clinical decision our prescribers make with you, based on your health, your history, and your goals, not on a milligram comparison alone.