Switching from Mounjaro to Wegovy for Maintenance: What Changes and What Stays the Same

You're stable on Mounjaro, so why would anyone switch?

Picture this: you've been on Mounjaro for the better part of a year. The dose increases are behind you, your weight has settled, and you're in what your prescriber called the maintenance phase. Then something shifts (availability, cost, a change in your health picture, or simply a conversation with your GP) and Wegovy enters the frame. It's a reasonable thing to explore. It's also where a common misconception tends to surface: that because both medicines are GLP-1-related weight-loss injections, switching between them is roughly equivalent to changing brands of the same product. It isn't, and setting that idea down gently matters here.

Mounjaro (tirzepatide) activates two receptors (GIP and GLP-1) which is why it's described as a dual agonist. Wegovy (semaglutide) targets only the GLP-1 receptor. That single-versus-dual mechanism is reflected in the trial data: in the SURMOUNT-5 head-to-head study, published in the New England Journal of Medicine in 2025, tirzepatide produced greater average weight reduction than semaglutide 2.4mg over 72 weeks. Switching mid-maintenance therefore isn't neutral; it's a meaningful clinical change that a prescriber needs to assess with your full picture in view.

There are legitimate reasons people make this switch. Mounjaro's UK list price rose sharply from September 2025, which changed the cost calculation for some patients. Others find Wegovy's side-effect profile suits them better. Some move because NHS access to one medicine opens up and not the other. None of these reasons is wrong. But each of them deserves a proper clinical conversation, not a self-managed changeover.

What a dose conversion actually involves, and why there isn't a simple table for it

One of the most searched questions around this switch is how doses map across. You can find a fuller breakdown on our Mounjaro-to-Wegovy dose conversion page, but the short answer is: there is no officially published equivalence table, because the two medicines work through different mechanisms and have different clinical weight-loss profiles. A prescriber approaching this switch typically considers your current Mounjaro dose, how well you tolerated it, your weight trajectory on it, and what outcome you're aiming to maintain.

The licensed Wegovy dose titration runs from 0.25mg up through 0.5mg, 1.0mg, 1.7mg, and 2.4mg, with each step taken over roughly four weeks. The MHRA approved a 7.2mg maintenance option in early 2026 (first as a multi-pen weekly regimen, then as a dedicated single-dose pen approved on 14 April 2026) which narrows the gap with tirzepatide's highest doses. What dose a switching patient would start at, and whether they'd restart titration from the beginning, is determined by the prescriber based on clinical judgement, not by matching dose numbers across the two medicines. If you're currently on 7.5mg or 10mg Mounjaro, for example, those specific situations are explored in the context of switching from 7.5mg Mounjaro and switching from 10mg.

NHS England's guidance on weight-management injections also notes that oral contraceptives may be less reliably absorbed during Mounjaro treatment (because tirzepatide slows gastric emptying more than semaglutide) a practical consideration that can itself influence which medicine is more appropriate for some patients.

Mounjaro vs Wegovy at maintenance: a factual comparison

The table below covers the key clinical and practical differences relevant to someone already in the maintenance phase of treatment. Numbers are cited from published sources; always read alongside a prescriber's guidance.

For a wider cost and value breakdown between the two medicines, our Wegovy vs Mounjaro cost comparison covers that ground. The broader head-to-head is on the Wegovy vs Mounjaro page.

How this switch is handled at nume, and what our prescribers assess

At nume, every switch from one medicine to another is treated as a fresh clinical assessment, not a form-filling exercise. A GPhC-registered Independent Prescriber reads through your consultation, your current dose, how long you've been on it, what your weight has done over that period, any side effects you've experienced, and what you want from the maintenance phase ahead. Transfer patients are asked for evidence of their current treatment. Dose increases on either medicine require clinical review, too. That applies whether you're switching from 12.5mg Mounjaro or moving from semaglutide in the other direction.

If you've been reading about what happens when you switch from Wegovy 2.4mg to Mounjaro, you'll notice that the clinical considerations run in both directions. The question isn't which medicine is objectively better, the SURMOUNT-5 data shows tirzepatide's advantage on average, but averages are population figures, and your situation is individual. Which medicine fits your maintenance goals, your tolerance, your wider health picture and your lifestyle is exactly what the consultation is designed to work out.

There are no waiting lists, no referrals needed and no subscriptions. Our clinical team reviews consultations the same day; if approved, treatment is dispatched before the day ends. You can review our general frequently asked questions or head straight to the treatment page to start your free consultation.

Which medicine suits your maintenance phase is a clinical decision our prescribers make with you.