How Does 2.4mg Wegovy Compare to Mounjaro by Dose?

What SURMOUNT-5 tells us about tirzepatide versus semaglutide 2.4mg

The SURMOUNT-5 trial is the most direct comparison available. It was an open-label, head-to-head study of 751 adults with obesity and no diabetes, running for 72 weeks, and it compared tirzepatide at its highest tolerated dose against semaglutide 2.4mg weekly. Tirzepatide produced a meaningfully greater average reduction in body weight. NICE's appraisal of tirzepatide (TA1026, December 2024) noted that indirect comparisons across the wider trial programme also favour tirzepatide over semaglutide 2.4mg, consistent with SURMOUNT-5's direct results.

For context, the earlier STEP 1 trial (published in the New England Journal of Medicine) found semaglutide 2.4mg produced an average body-weight reduction of around 15% over 68 weeks in adults with obesity. SURMOUNT-1 showed tirzepatide at 15mg achieving average reductions in the region of 20–21% over 72 weeks. These are population averages from controlled trials; individual results vary, and neither figure is a prediction for any one person.

One thing worth flagging: comparing Wegovy and Mounjaro is not simply a matter of matching milligram to milligram. Semaglutide and tirzepatide act on different receptors entirely, semaglutide targets GLP-1 alone, while tirzepatide activates both GLP-1 and GIP receptors. The dose numbers sit on completely separate scales and cannot be converted directly.

How the dose scales actually differ between the two medicines

Wegovy's maintenance dose for weight management has traditionally been 2.4mg weekly, titrated up from 0.25mg over approximately five months. In April 2026 the MHRA approved a 7.2mg single-dose pen as a higher maintenance option, narrowing the gap with tirzepatide's results somewhat, trials of the 7.2mg dose reported average weight loss of around 20.7% at 72 weeks. The NHS semaglutide medicines page covers the titration schedule and side-effect profile for patients.

Mounjaro's scale runs 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg, with the prescriber titrating in roughly four-week steps. The 2.5mg starting pen is a tolerability phase (the body adjusting to the medicine) not the therapeutic target. If you are curious how an earlier dose on that ladder compares, our page on 5mg Mounjaro sets that out. The key practical point is that 2.4mg semaglutide sits towards the top of Wegovy's original scale, while 2.4mg is also very close to the bottom of Mounjaro's scale, yet the two numbers describe entirely different biological effects because the drugs act differently.

A quick look at what the licensed UK doses cover:

All figures are trial averages and are cited from NICE technology appraisals TA1026 and the respective NEJM publications; individual outcomes differ.

Which patients each medicine is licensed for in the UK

Both medicines share broadly similar eligibility criteria under their UK licences: adults with a BMI of 30 or above, or 27 and above alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, or obstructive sleep apnoea. NICE's recommendation for tirzepatide (TA1026) sets the NHS threshold at BMI 35 or above plus at least one qualifying comorbidity. NICE's recommendation for semaglutide (TA875) adds a two-year maximum treatment duration and requires use within a specialist weight management service for NHS access. Lower BMI thresholds apply for certain ethnic backgrounds under both appraisals.

Privately (which is the route nume offers) the prescriber works from the licensed criteria and the whole clinical picture, not just a BMI number. Our prescribers review every consultation personally; the clinical team page sets out who is overseeing that process. If you are mid-treatment on one medicine and considering a switch, that conversation starts with a clinical review, not a dose-conversion chart. Our dose conversion guidance explains why there is no simple milligram-for-milligram equivalence between these two drugs.

Neither medicine is recommended during pregnancy, whilst breastfeeding, or for those actively trying to conceive, and neither is licensed for anyone under 18.

What to consider if you are thinking about switching or starting

People switching from Wegovy to Mounjaro (or vice versa) sometimes assume they can map their current dose to an equivalent. They cannot, and doing so carries genuine clinical risk. The prescriber needs to know your current dose, how long you have been on it, your weight trajectory and your side-effect history before recommending a starting point on the new medicine. A question our prescribers hear regularly is whether a higher Mounjaro dose might make up for a plateau on 2.4mg Wegovy, and if you are weighing up moving from 2.4mg Wegovy to Mounjaro, our dedicated page walks through what that transition involves clinically. The honest answer on whether it might help is that it depends on factors only a clinical review can assess, and if you want to understand what Wegovy 2.4mg is equivalent to on the Mounjaro scale, that page explains why no straightforward figure exists.

Cost is part of the picture too. A side-by-side cost comparison helps set expectations; what matters alongside price is what that price includes, prescription, clinical oversight and aftercare. For a prescription medicine, the cheapest listing is the wrong test. The right test is whether supply is genuine, clinical review is real, and support is available when you need it. Our FAQs cover common switching and access questions, and you can reach the clinical team directly through our contact page.

Which medicine suits you is a clinical decision our prescribers make with you, based on your health history, your response to treatment and your goals, not on a comparison table alone.