Wegovy Dosage Compared to Mounjaro: What the Schedules Actually Mean

Step 1: How each escalation schedule is structured

Wegovy starts at 0.25mg once weekly. That first dose is purely about letting your body adjust; the therapeutic work builds gradually as the dose climbs through 0.5mg, 1.0mg and 1.7mg, arriving at the standard 2.4mg maintenance dose after roughly five months of four-weekly steps. You can read the full patient-level detail in the NHS medicines page for semaglutide. From January 2026, the MHRA also approved a higher 7.2mg dose of Wegovy — an option your prescriber can consider if you've reached 2.4mg and further progress is a clinical priority.

Mounjaro works differently from the start. It begins at 2.5mg weekly, a dose whose job is to settle your digestive system before treatment properly begins. The schedule then climbs in 2.5mg increments every four weeks (to 5mg, 7.5mg, 10mg, 12.5mg and finally 15mg) though many people find a lower maintenance dose is sufficient and appropriate for them. The NHS tirzepatide medicines page covers the schedule clearly for patients.

The practical upshot: Mounjaro's dose ladder has more rungs and a higher ceiling. But neither schedule should be self-directed. Your prescriber sets the pace based on how you're tolerating each dose, not a fixed calendar.

Step 2: The mechanism behind the numbers

Why do the milligrams look so different? The two molecules work via distinct receptor pathways, so the doses aren't interchangeable units. Wegovy activates GLP-1 receptors, one pathway involved in appetite regulation and glucose control. Mounjaro activates both GLP-1 and GIP receptors simultaneously, making it the only dual-agonist weight-loss medicine licensed in the UK. Dual activation changes the dose-response relationship, which is why 15mg of tirzepatide cannot be meaningfully compared with 2.4mg of semaglutide by number alone. A deeper look at the clinical comparison is available on our Wegovy vs Mounjaro overview.

Both medicines slow gastric emptying and increase feelings of fullness between meals. The difference in mechanism is one reason the trial results at peak doses diverge, more on that below.

Step 3: What the evidence says at each medicine's top dose

The two pivotal trials used different populations, durations and endpoints, so direct comparison comes with caveats. That said, the SURMOUNT-5 head-to-head trial (published in the New England Journal of Medicine in 2025) compared tirzepatide directly against semaglutide 2.4mg in adults with obesity and no diabetes. Tirzepatide produced greater average weight reduction over 72 weeks. NICE's appraisal of tirzepatide (TA1026) acknowledges that indirect comparisons also favour tirzepatide at comparable trial durations.

At Wegovy's standard 2.4mg dose, STEP 1 (68 weeks) showed around 15% average body-weight reduction. If you want to understand how each Wegovy dose compares to Mounjaro across the full escalation schedule, we cover that in detail separately. At 7.2mg, trial data reported approximately 20.7% average reduction over 72 weeks, which narrows the gap with tirzepatide's 15mg results considerably. At Mounjaro's 15mg dose, SURMOUNT-1 (72 weeks) recorded average reductions of around 20–21%.

One note worth making explicit: Ozempic is also semaglutide, and Rybelsus is also semaglutide in tablet form, but both are licensed for type 2 diabetes management, not weight loss. If you've been reading about those medicines in a weight-loss context, the licensed product is Wegovy. For a closer look at how a specific dose of Wegovy lines up against Mounjaro in practice, the Wegovy 2.4mg vs Mounjaro comparison goes into more detail.

Step 4: Storage, routine and what to expect day to day

Both medicines are once-weekly injections stored in the fridge, the door shelf works well for most people, as long as it's kept between 2°C and 8°C. Neither should be frozen. Each pen has a limited window at room temperature if you're travelling; the exact duration is in the Patient Information Leaflet rather than here, because getting that detail from the leaflet rather than a web page matters. Always check yours.

Side effects for both are led by the digestive system: nausea, loose stools, constipation and indigestion are the most commonly reported, particularly after starting or moving up a dose. They usually ease within a week or two as your body settles. A question our prescribers hear most weeks is whether one medicine tends to cause more nausea than the other, and if you're currently on the 1mg Wegovy step and weighing up your options, our page on how 1mg Wegovy compares to Mounjaro addresses that stage of treatment specifically.

If dose conversion between the two medicines is relevant to your situation (perhaps you're already on one and wondering about switching) the guide to Mounjaro-to-Wegovy dose conversion addresses that specifically. Questions about cost differences are covered on our explainer on why Wegovy is typically priced lower than Mounjaro.

Which medicine suits your situation is a clinical decision, made with our prescribers after a full assessment. Both are prescription-only medicines, suitability depends on your health history, any medicines you're already taking, and what your goals are. You can check your eligibility through a free consultation, reviewed the same day by a real clinician.