Looking for a Mounjaro substitute? Here's what's actually available

You've heard Mounjaro is out of stock, or it wasn't right for you. Where does that leave you?

Supply disruptions happen, and so do clinical reasons to try a different approach. If you've been on tirzepatide and had to pause, or if Mounjaro was never prescribed in the first place and you're wondering what else qualifies, it's worth understanding the landscape clearly rather than searching for a shortcut.

The short answer: in the UK, the realistic alternatives licensed for weight management are semaglutide-based medicines, specifically Wegovy as a weekly injection and, since June 2026, Wegovy as a once-daily tablet. Both work on the GLP-1 receptor, which Mounjaro also targets, but tirzepatide adds a second mechanism (the GIP receptor) that the semaglutide options don't. That distinction matters clinically, which is why trial data shows average weight loss at the highest tirzepatide dose running a few percentage points ahead of semaglutide 2.4mg, as demonstrated in the SURMOUNT-5 head-to-head trial published in the New England Journal of Medicine.

None of this means semaglutide is a poor substitute, for many people it's highly effective. It means the choice deserves a proper conversation with a prescriber, not a Google decision.

What Wegovy injection and Wegovy tablets offer as alternatives to tirzepatide

Wegovy (semaglutide 2.4mg injection, and now up to 7.2mg) is licensed for adults with a BMI of 30 or above, or 27 and above with a weight-related condition. The STEP 1 trial reported an average weight reduction of around 15% over 68 weeks at the 2.4mg maintenance dose. The newer 7.2mg dose, approved by the MHRA as a dedicated single-dose pen in April 2026, brought average losses closer to around 20.7% in trials, narrowing the gap with tirzepatide's results considerably. The NHS sets out the access criteria and practical guidance for weight-management injections in detail.

The Wegovy tablet (the first oral GLP-1 medicine licensed in the UK for weight loss, approved in June 2026) is taken once daily, first thing in the morning on an empty stomach with a small amount of plain water, before any food or coffee. No refrigeration needed, which many people find easier to manage than an injection. Trial data (OASIS 4, 64 weeks) reported roughly 13.6% average weight loss versus placebo, rising to around 17% among participants who adhered fully. If you're curious about the broader range of options, our treatment page explains what's currently available through a num prescription.

A note on orlistat: it's an older medicine that blocks fat absorption and is available at prescription strength. It has a very different mechanism and side-effect profile and is rarely someone's first choice when they've already been considering tirzepatide, but it does exist as a licensed option worth knowing about.

What isn't a genuine substitute, and why this matters for your safety

A question our prescribers hear regularly: can Ozempic be used instead of Mounjaro for weight loss? The honest answer is no, not legally. Ozempic is semaglutide licensed for type 2 diabetes. Rybelsus is the oral version of the same medicine, also for diabetes. Neither is licensed for weight management in the UK, and prescribing either off-licence for that purpose falls outside standard clinical practice. The NHS tirzepatide information page is a useful starting point for understanding what Mounjaro is and isn't approved for.

Further away from legitimacy are compounded or reconstituted tirzepatide preparations sold online. These are not licensed medicines, and the MHRA has flagged significant risks from counterfeit and unregulated GLP-1 products. If you've seen references to reconstituted tirzepatide, our pages on what reconstituted tirzepatide actually is and how the reconstitution process works explain the situation clearly, and if you have questions about a specific strength, our guide to reconstituting the 30mg tirzepatide vial covers that in detail. The key point: genuinely licensed Mounjaro is a pre-filled KwikPen. If a seller is offering something that requires mixing, it isn't the licensed medicine.

For a prescription medicine, the right question isn't which option is easiest to obtain, it's which one is clinically appropriate for you, from a pharmacy you can verify on the GPhC register. Worth checking before you hand over payment details anywhere.

How a prescriber works through the substitute question with you

Switching from tirzepatide to semaglutide (or vice versa) isn't something that happens by filling in a form. A prescriber needs to understand why the original medicine is being reconsidered, your current dose and how long you've been on it, any side effects you experienced, and your broader health picture. People already established on Mounjaro who need a break, for instance, may be in a different position to someone starting fresh. If you've come across unlicensed vials and want to understand the practicalities, our full guide on reconstituting tirzepatide at home explains what that process actually involves, and our overview of reconstituting tirzepatide generally sets out the broader context around why licensed alternatives are the safer route.

At nume, a GPhC-registered prescriber reads every consultation personally, the same day it arrives. No automated decisions. If you're transferring from another provider, you'd provide evidence of your current treatment as part of that review. Our Mounjaro overview covers the full licensed schedule, and details on our clinical team are on the clinical team page if you'd like to know who'd be reviewing your case.

The 12pm cut-off matters here: consultations received before noon on a working day are reviewed the same day, with treatment dispatched same-day if clinically approved and delivered free the next working day by DPD. If a switch is clinically right for you, there's no reason to wait weeks. Speak to our prescribers to work through the options that fit your situation.