Switching from Wegovy to Mounjaro: What You Need to Know

Wegovy (semaglutide) and Mounjaro (tirzepatide) are both once-weekly injectable prescription medicines used in weight management, but they work differently. Wegovy acts on a single pathway — the GLP-1 receptor. Mounjaro acts on two: both GLP-1 and GIP receptors. That dual mechanism is why they are distinct medicines, not interchangeable versions of the same thing.

Because they are different compounds at different dose strengths, there is no simple conversion that maps one dose directly onto the other. For example, someone on the 1.7 mg Wegovy dose or the 2.4 mg Wegovy maintenance dose cannot assume a straightforward Mounjaro equivalent exists — your prescriber will decide where to start based on clinical judgement, not a fixed formula. For a closer look at how the dose ranges compare in general terms, see our Wegovy to Mounjaro dose comparison overview.

Both medicines are prescription-only and subject to additional monitoring. Any side effects should be reported to your healthcare professional and to your national reporting scheme (such as the UK's Yellow Card scheme or your country's equivalent).

If you are thinking about making this change, the pages on whether switching from Wegovy to Mounjaro is possible and what swapping between these medicines involves cover the topic in more detail. For broader context on Mounjaro, the Mounjaro information hub is a good starting point.

What typically happens when a switch is made

When a prescriber decides a switch is appropriate, Mounjaro is generally started at its lowest available dose — the same cautious, stepwise approach used when beginning the medicine for the first time. Titration then follows the prescriber's guidance. This is not a reflection of where someone was on Wegovy; it is simply how the medicine is introduced safely. Any questions about where you would start, how quickly you might titrate, or whether a switch is right for you should go directly to your prescriber.

Starting a new medicine — even one in the same class — means your body may respond differently. Logging how you feel during the transition is one of the most practical things you can do, both for your own awareness and to give your prescriber useful information at your next appointment.

GLP Trackr's side-effect and symptom tracking lets you record how you feel day to day — nausea, fatigue, energy levels, and anything else worth noting — and surfaces patterns over time. If you notice a change in how side effects present compared with your previous medicine, that record can be genuinely useful when you discuss it with your prescriber. The app also logs each dose, date, and strength, so your injection history is clear from day one on the new medicine — no mental arithmetic about when you last injected or which pen you are on.

As your appetite and food noise may shift again during a switch, GLP Trackr's food logging (including AI photo scan) makes it easy to keep track of protein and calories even when your appetite is unpredictable.

Always follow the guidance of your prescriber throughout any medicine change — they know your full history and are best placed to support you through the transition. If you experience symptoms that are severe, persistent, or concern you, contact your healthcare professional promptly.

GLP Trackr is free to try for 7 days on the App Store and Google Play. If you are starting Mounjaro after Wegovy, it is a good moment to start logging everything from the beginning — download the app and begin your 7-day free trial on iOS or Android.