Switching from 7.5mg Mounjaro to Wegovy: What You Need to Know

Why would someone on 7.5mg Mounjaro consider switching to Wegovy?

It's a reasonable question, and the answers vary. Supply issues are one driver, there have been periods when specific Mounjaro strengths were harder to source through UK pharmacies. Cost is another factor for some people, though the two treatments sit in a similar private price bracket these days. A smaller group switch because their prescriber or GP has a clinical reason to prefer semaglutide: a documented reaction to tirzepatide's GIP pathway, for example, or a preference aligned with a specific comorbidity.

What's worth understanding is that 7.5mg Mounjaro sits mid-way through tirzepatide's licensed schedule. You've already spent several months on treatment, your body has adapted to the dose escalation, and switching means starting a new titration sequence on a different molecule. That isn't automatically a problem, but it does mean the first few weeks on Wegovy may feel like a step back in terms of appetite suppression, simply because you'll begin at a lower dose while your system adjusts. Your prescriber will weigh all of this when reviewing your request, it's not a decision that should happen without that conversation.

The detailed comparison of Wegovy and Mounjaro covers the mechanism differences more fully, which is worth reading alongside this page if the decision is still open for you.

How do the doses compare side by side?

There is no perfect one-to-one conversion between tirzepatide and semaglutide because they are different drugs acting on overlapping but distinct receptor pathways. Mounjaro activates both GIP and GLP-1 receptors; Wegovy acts on GLP-1 alone. That distinction matters when thinking about dose equivalence, a 7.5mg tirzepatide dose cannot simply be mapped to a milligram figure on the semaglutide scale.

The table below gives a factual overview of the licensed UK schedules and the trial weight-loss outcomes associated with each maintenance dose. The figures are drawn from the SURMOUNT-1 and STEP 1 trials, published in the New England Journal of Medicine, and from the SURMOUNT-5 head-to-head trial (NEJM, 2025), which compared tirzepatide directly against semaglutide 2.4mg in adults with obesity.

For a closer look at how prescribers approach the dose question in practice, our dose conversion guide explains the reasoning in more detail. People switching at lower Mounjaro doses often find the comparison easier to navigate than those further up the schedule.

What does starting Wegovy actually involve after being on 7.5mg Mounjaro?

Wegovy's licensed titration begins at 0.25mg, regardless of what you were taking previously. That starting dose exists to reduce early GI side effects (nausea, loose stools, stomach discomfort) which are common to both treatments but tend to be most noticeable when the drug is new to your system. Even experienced GLP-1 users report that switching molecules can briefly reawaken those early effects.

From 0.25mg, the standard schedule moves through 0.5mg, 1.0mg, 1.7mg and then 2.4mg, typically at four-week intervals set by the prescriber, with 7.2mg now available as a higher maintenance option following MHRA approval in April 2026. The NHS patient information for semaglutide at nhs.uk/medicines/semaglutide sets out the side-effect profile in plain terms and is worth bookmarking for the early weeks.

One practical note: if you're planning a switch and timing matters to you (payday, a holiday coming up, or you want to start on a Monday for routine's sake) factor in that the full journey to Wegovy's maintenance dose takes several months. If you are specifically considering a move from 10mg Mounjaro to Wegovy, there is dedicated guidance that covers how that slightly higher starting point affects the process. The dosage guide for Mounjaro to Wegovy switches has a realistic timeline to set against your calendar. Our prescribers will confirm the schedule that fits your specific situation at consultation.

Which treatment is right for you, and how is that decided?

This is genuinely not a question with a universal answer. The trial data favours tirzepatide for average weight loss at equivalent stages, but some people respond well to semaglutide and less well to Mounjaro's dual-agonist mechanism, or have a clinical history that points in a different direction. The MHRA-approved Wegovy 7.2mg dose has meaningfully narrowed the gap between the two treatments, which changes the calculus for patients who can tolerate escalation on semaglutide.

Cost is part of the picture too. For a grounded view of how private pricing for both treatments compares in the UK, the price comparison page is the right starting point. And if you've read enough and want to put the question directly to a prescriber, the place to do that is our consultation page.

Which treatment suits you is a clinical decision our prescribers make with you, based on your weight history, current dose, any side effects you've experienced, and your goals. Our clinical team includes GPhC-registered Independent Prescribers who review switch requests with the same rigour as a new consultation. If you'd like to explore switching in the other direction, that guidance is available separately.