Can You Move from Mounjaro to Wegovy (or the Other Way Around)?

What actually drives this decision — and why it isn't just about weight loss numbers

Many people assume that switching from one GLP-1 medicine to another is simply a matter of picking whichever one produced bigger trial results. That is understandable, but it misses most of the picture. If you are weighing up whether Wegovy or Mounjaro is the better option for you, the answer depends on factors that are specific to you: why your current treatment isn't working as hoped, whether side effects are the reason you want to change, what conditions you're managing alongside weight, and how far into your treatment journey you are.

Mounjaro activates two gut-hormone receptors, GIP and GLP-1, which is why it's described as a dual agonist. Wegovy works on GLP-1 alone. That mechanistic difference matters clinically, and it may matter to your prescriber's thinking when you raise the question of switching. A prescriber reviewing a request to move from Wegovy to Mounjaro, or in the other direction, would want to understand the reasoning before making any recommendation.

It is also worth knowing that switching is not instant. There is no established universal protocol for moving between these two medicines, and a prescriber would need to consider timing, your current dose, and what starting dose on the new medicine would be appropriate. The practical steps for moving from Mounjaro to Wegovy are worth reading alongside this page, because the how matters as much as the whether.

How the two medicines compare on the evidence that exists

The most direct evidence comes from SURMOUNT-5, an open-label head-to-head trial published in the New England Journal of Medicine in 2025, which found that tirzepatide produced greater average weight reduction than semaglutide 2.4mg over 72 weeks in adults with obesity and no diabetes. NICE's appraisal of tirzepatide (TA1026) also noted that indirect comparisons tended to favour tirzepatide. That said, the gap is not absolute.

Wegovy's highest licensed dose has been extended. The MHRA approved a dedicated single-dose 7.2mg pen in April 2026, with trial data reporting around 20.7% average weight loss over 72 weeks, a figure that narrows the difference from tirzepatide's 15mg results considerably. The table below sets out the headline comparison factually.

Neither medicine is universally better for every person, and the full Wegovy vs Mounjaro comparison covers the nuances in more depth. A number is not a prescription.

Reasons people consider switching, and what a prescriber looks at

The reasons people want to move from Mounjaro to Wegovy, or the other way, tend to cluster around a few patterns. Some people find the gastrointestinal side effects of one medicine harder to tolerate than expected. Others have heard about the dual mechanism of Mounjaro and want to try it after experiencing a plateau on Wegovy. Some are motivated by the availability of an oral option: Wegovy tablets, approved by the MHRA in June 2026, are the first oral GLP-1 medicine licensed for weight management in the UK, and for people who find weekly injections difficult, that matters.

Then there are supply questions, which are real but temporary: a shortage of one strength does not automatically mean the other medicine is the clinical answer. A prescriber at a regulated service like ours would want to distinguish a preference based on supply from one based on clinical need.

People also often ask whether it is actually possible to go from Mounjaro to Wegovy, and both the NHS's tirzepatide medicines page and the equivalent semaglutide guidance note that changes to treatment should be discussed with a prescriber. That applies to switching as much as it applies to titration. If you are thinking about moving from Mounjaro to Wegovy, it is worth articulating your reasons clearly when you speak to a prescriber, because it helps them give you an honest answer rather than a reflexive one.

How to raise a switch at your next clinical review

If you are already on treatment and considering a switch, your next clinical review is the right moment. At nume, sorry, at our service every repeat order goes through a full clinical re-review before dispatch, which means the prescriber is already looking at your progress. That is the moment to raise it.

If you are new to treatment and trying to decide which medicine to start, the comparison is one input among several. Our prescribers consider your BMI, any weight-related conditions, your medical history, your preferences (including whether injections or tablets suit you), and what the clinical evidence supports for your individual situation. You can explore the broader treatment options on our weight-loss treatment overview, or read about what moving from Mounjaro to Wegovy involves in practice on our guide to swapping between the two medicines.

Which of these medicines suits you is a clinical decision our prescribers make with you, not one this page can make for you. Numbers from trials are a starting point. Your situation is the rest of it.