Saxenda vs Mounjaro: comparing two weight-loss injections

You've been looking at both pens and realise the choice is less obvious than it first appeared

Most people arrive at this comparison after searching for the cheapest weekly injection and noticing that Saxenda comes up alongside Mounjaro. It's a reasonable starting point, but the two medicines are not interchangeable. Saxenda contains liraglutide, a GLP-1 receptor agonist given as a daily injection in doses rising from 0.6 mg to a 3 mg maintenance dose. Mounjaro contains tirzepatide, which activates both GIP and GLP-1 receptors, a dual mechanism that no other licensed weight-loss medicine currently uses in the UK. That biological difference plays out in the trial data.

In the SCALE trial programme, Saxenda produced average weight loss of roughly 5–8% over 56 weeks at the 3 mg dose. The SURMOUNT-1 trial, involving 2,539 adults with obesity, reported average weight reductions of around 20–21% over 72 weeks at the highest tirzepatide dose, as published in the New England Journal of Medicine. Those are not comparable numbers. That said, both are prescription-only medicines and neither guarantees any particular result for any individual, trial averages describe populations, not predictions.

One practical detail worth knowing: Saxenda requires a daily injection; Mounjaro is once weekly. For some people that difference alone settles the question, and our full breakdown of Saxenda compared to Mounjaro walks through each of those differences in more detail if you want to read further before speaking to a prescriber. For others, the licensing status is what matters most.

Saxenda is no longer licensed for weight management in the UK, what that means for you

This is the part many comparison pages skip over. Saxenda's UK marketing authorisation for weight management was withdrawn by Novo Nordisk in 2024, meaning it is no longer an authorised treatment option for weight loss in the UK. It has not been recalled for safety reasons (liraglutide itself is still used in Victoza for type 2 diabetes) but as a weight-management product, Saxenda is no longer licensed here.

The practical consequence is that a UK prescriber cannot lawfully prescribe Saxenda for weight management under a standard authorisation. Any pharmacy or clinic currently offering it for this purpose is operating outside normal licensing. The NHS tirzepatide page and NICE guidance both point to the medicines that are currently authorised for weight management in UK adults: tirzepatide (Mounjaro) and semaglutide (Wegovy). That is why this page exists to inform rather than to facilitate access to Saxenda.

If you were previously prescribed Saxenda and are wondering what comes next, that is a conversation worth having with a prescriber. Our page on switching from Saxenda to Mounjaro covers the practicalities in more detail.

What the numbers look like side by side

The table below draws on published trial evidence and current UK licensing information. Individual results will differ.

NICE recommended tirzepatide for NHS use in December 2024, setting eligibility criteria for adults with a BMI of 35 or above alongside at least one weight-related condition, with lower thresholds applying for some ethnic backgrounds under that guidance. Private eligibility follows the licensed criteria: adults with a BMI of 30 or above, or 27 or above with at least one weight-related condition, though BMI alone never determines the outcome; the prescriber assesses the full picture.

What is licensed for weight loss in the UK now, and how nume (sorry) how nume fits in

The two medicines currently licensed for weight management in UK adults are Mounjaro (tirzepatide) and Wegovy (semaglutide, injection and, since June 2026, oral tablet). Our weight-loss treatment overview sets out how they differ, and our prescribers work through that with each patient individually. Saxenda is not something we dispense for weight management, and this page will not point you toward a route to obtain it.

If you want to understand the Mounjaro option in more depth (how it works, what the starting dose means, how it is typically titrated) our Mounjaro information page covers the clinical detail. Questions about cost sit on a separate page: Mounjaro pricing in the UK explains what private treatment typically includes and why the headline figure can look different between providers.

For anyone who wants to explore alternatives beyond these two, we have compared Mounjaro with other agents including Mysimba and newer investigational medicines such as retatrutide, so you can read around the landscape before speaking to a prescriber. Payday, Monday orders, pre-holiday timing, whenever you are ready, a same-day clinical review is available. Speak to our prescribers through the consultation page and the choice between agents becomes a conversation, not a guessing game.

Which approach suits you is a clinical decision our prescribers make with you, based on your health history, your preferences and what the evidence actually shows.