Thinking About Moving from Mounjaro to Ozempic? Read This First

The decision you're actually facing: Mounjaro vs Ozempic vs Wegovy

When people ask about moving from Mounjaro to Ozempic, they usually mean one of two things: their prescriber has mentioned switching, or they've seen Ozempic discussed online and wonder whether it might suit them better. It's a question our prescribers hear most weeks, and the honest answer starts with the licensing position.

Ozempic is semaglutide at doses of 0.5mg, 1mg or 2mg, manufactured by Novo Nordisk. Its UK licence covers blood-sugar management in type 2 diabetes. It is not licensed for weight management. Mounjaro is tirzepatide, a dual GIP and GLP-1 receptor agonist licensed for weight management in adults with a BMI of 30 or above, or 27 and above with a weight-related condition. If your aim is sustained weight loss, a prescriber cannot lawfully prescribe Ozempic for that purpose under the weight-management indication. The licensed weight-loss semaglutide product is Wegovy, which reaches 2.4mg weekly, and now up to 7.2mg with the MHRA's April 2026 approval of the new single-dose pen. For a broader look at how these two medicines compare by indication, our page on Ozempic and Mounjaro covers the licensing distinctions in full.

So the genuine decision for most people is: stay on Mounjaro, or switch to Wegovy? That's where the comparison becomes clinically meaningful.

How the clinical evidence actually stacks up

Because Ozempic and Mounjaro are licensed for different conditions, there's no head-to-head trial comparing them for weight loss. The relevant comparison is tirzepatide against semaglutide 2.4mg. SURMOUNT-5, published in the New England Journal of Medicine in 2025, was the first randomised head-to-head: it found tirzepatide produced greater average weight reduction than semaglutide 2.4mg over 72 weeks in adults with obesity. SURMOUNT-1 reported average body-weight reductions of around 20–21% at tirzepatide 15mg. STEP 1 reported around 15% average reduction with semaglutide 2.4mg over 68 weeks. The new 7.2mg Wegovy dose narrows that gap, with trials reporting roughly 20.7% average loss over 72 weeks, per the MHRA's April 2026 approval announcement.

The table below sets out the key factual differences.

Sources: NICE TA1026 tirzepatide appraisal; NICE TA875 semaglutide appraisal; SURMOUNT-5 and SURMOUNT-1, NEJM 2025 and 2022.

If you're weighing a switch, what actually matters

The factors that make a medicine switch appropriate are clinical, not commercial. Side-effect tolerance is usually the first: both tirzepatide and semaglutide share a GI-led profile (nausea, loose stools, reduced appetite) because they both activate GLP-1 receptors, slowing gastric emptying. Moving between them doesn't escape that profile. What can differ is magnitude and timing. Some people find one molecule sits better with their system; that's something a prescriber tracks over time rather than predicts in advance.

Weight-loss response is the second factor. If someone has plateaued on Mounjaro at their highest tolerated dose and hasn't reached a clinically meaningful target, the question isn't whether Ozempic would help more (it wouldn't, and it isn't licensed for this) but whether there's a different approach within the licensed weight-management pathway. The comparison page on switching between semaglutide and tirzepatide covers that direction too.

Contraindications and interactions are the third consideration. Tirzepatide carries specific guidance for women using oral contraceptives: add a non-oral method for the first four weeks of treatment and for four weeks after each dose increase, because absorption of the pill may be affected, per NHS England's wraparound care guidance. Semaglutide doesn't carry the same caution. That's one practical factor that sometimes shapes the conversation. A prescriber weighs all of this (your history, your response, your other medicines) before any switch is recommended. Which medicine suits you is a clinical decision our prescribers make with you.

What IS available for weight loss, and how to access it

Both Mounjaro and Wegovy are licensed UK medicines for weight management and dispensed by nume through our weight-loss treatment pathway. Ozempic is not something our prescribers can offer for weight loss, not because of a gap in our service, but because the licence doesn't permit it. Any pharmacy offering Ozempic for weight management would be operating outside the medicine's authorised indication.

If you're already on Mounjaro and wondering whether it's the right medicine for you, or you've heard about Wegovy versus Mounjaro and want to understand the difference, our prescribers work through that at consultation. Treatment is only prescribed where it's clinically appropriate. There's no waiting list, no referral, and the initial consultation is free. You can also read more about our clinical team on the clinical team page, or explore the full range of weight-loss treatment options we support. For anything else, contact our team directly.