Is Wegovy the Same as Mounjaro? What the Differences Actually Mean for You

You've seen both names and can't work out if they're the same thing

This is one of the questions our prescribers hear most weeks, and the confusion is understandable. Wegovy and Mounjaro sit on the same shelf in the weight-management conversation, both are injectable GLP-1 class treatments, both require a prescription, and both are dispensed by regulated UK pharmacies. Beyond that, the similarity breaks down fairly quickly.

Wegovy contains semaglutide, made by Novo Nordisk. Mounjaro contains tirzepatide, made by Eli Lilly. Semaglutide activates one receptor: GLP-1, which is involved in appetite regulation and slowing gastric emptying. Tirzepatide activates two: GLP-1 and GIP. That dual action is why Mounjaro is sometimes described as a different generation of treatment, it is the only dual-agonist weight-loss medicine currently licensed in the UK. If you want to understand whether Wegovy is truly equivalent to Mounjaro before going deeper on the molecular detail, that page sets out what they share and where they meaningfully differ. If you want to go deeper on how tirzepatide and semaglutide relate at a molecular level, our page on whether tirzepatide is the same as Wegovy covers that in detail.

For practical purposes: same injection day routine, different drugs, different average outcomes in trials, different NICE criteria on the NHS.

What the trial numbers show when you put them side by side

The table below draws from the pivotal trials and the first direct head-to-head comparison. Numbers are averages from specific study populations; individual results vary.

The SURMOUNT-5 result narrows when Wegovy's newer 7.2mg dose is factored in, though direct 7.2mg trial data against tirzepatide is not yet available. As NICE notes in its appraisal of tirzepatide (TA1026), indirect comparisons consistently favour tirzepatide, but both medicines produce clinically meaningful weight loss. For a fuller breakdown of how results compare across the dose ladder, see our Wegovy vs Mounjaro results comparison.

Same side-effect profile or meaningfully different?

Because both medicines act on GLP-1 receptors, the side-effect landscape overlaps. Nausea is the most commonly reported effect for both, typically peaking in the first few weeks after starting or after a dose step. Vomiting, loose stools, constipation, reflux and fatigue feature in both profiles. Neither medicine is predictably easier to tolerate than the other at a population level; that tends to come down to individual biology and how carefully titration is managed.

The NHS patient information for tirzepatide and for semaglutide both flag the same urgent warning: severe or persistent stomach pain that radiates to the back should be assessed immediately, as it may indicate pancreatitis. The MHRA reinforced this point in a Drug Safety Update in January 2026. Storage is also comparable: both pens are refrigerated. The Mounjaro KwikPen goes back in the fridge door after each weekly dose just like a Wegovy pen, that part of the routine is identical.

Both medicines carry a Black Triangle (▼) in the UK, meaning they are under additional MHRA monitoring. Neither is recommended in pregnancy, while breastfeeding, or for anyone trying to conceive. They are not licensed for use under the age of 18. For a closer look at how the two medicines compare specifically on tolerability, our page on whether Wegovy works the same as Mounjaro adds more context.

Which one are you likely to be prescribed?

On the NHS, the criteria differ. Mounjaro (tirzepatide) is recommended by NICE under TA1026 for adults with a BMI of 35 or above and at least one qualifying weight-related condition, with rollout phased through 2027. Wegovy is recommended under NICE TA875 but only through specialist weight management services, with a two-year treatment limit. Waiting times for both NHS routes can be considerable.

Through a regulated private pharmacy like nume, both medicines are available to eligible adults without a referral or a waiting list, subject to a prescriber confirming clinical suitability. Lower BMI thresholds apply for some ethnic backgrounds under current UK guidance. BMI alone is not the whole picture; the prescriber reviews your full health profile before any prescription is issued.

There is no universally correct answer to which is better. Tirzepatide's dual mechanism and trial data make it a strong candidate for many people, but semaglutide has a longer post-licensing track record and, in its oral form (Wegovy tablets, approved by the MHRA in June 2026), now offers an injection-free route. See our Wegovy v Mounjaro page and our cost comparison for more detail on pricing. Which suits you is a clinical decision our prescribers make with you. Start your free consultation and the conversation begins there.