Can I Swap from Wegovy to Mounjaro?

Wegovy and Mounjaro are both once-weekly injectable prescription-only medicines used for weight management, but they work differently. Wegovy contains semaglutide, a GLP-1 receptor agonist. Mounjaro contains tirzepatide, which acts on both GLP-1 and GIP receptors — a dual mechanism. Because they are different active substances at different dose strengths, you cannot simply substitute one for the other at the same numerical dose.

Why a straight swap is not straightforward

The dose scales for the two medicines are entirely separate. A dose of Wegovy and a dose of Mounjaro with the same number on the label are not equivalent. There is no universal, patient-led conversion that is safe to apply without clinical input. Your prescriber will consider your current dose, how well you have been tolerating the medicine, your medical history, and the appropriate starting point for the new medicine. See the Wegovy to Mounjaro dose comparison page for a factual overview of the two dose scales, but always treat any such comparison as background information rather than a personal dosing guide.

Reasons people consider switching

People ask about moving from Wegovy to Mounjaro for a range of reasons — curiosity about the dual-receptor mechanism, changes in availability, tolerability of side effects, or simply wanting to explore options with their prescriber. None of these are reasons to switch on your own. If you are wondering whether a change might suit you, the right step is to raise it at your next clinical appointment. For a fuller look at how the two medicines compare factually, the Wegovy and Mounjaro overview covers the key differences in a neutral, side-by-side way.

What to expect if your prescriber agrees to a switch

If your prescriber does decide a switch is appropriate, they will typically start you at a low introductory dose of the new medicine rather than matching your current dose numerically. There is usually a re-titration period, meaning your body adjusts to the new medicine gradually — much like when you first started. Side effects that had settled may temporarily reappear. Your prescriber or doctor is the right person to walk you through what to expect. You can also read more on the changing from Wegovy to Mounjaro page for further informational context.

If you do make a switch — or are preparing to discuss one — having a clear record of your journey so far is genuinely useful. GLP Trackr's dose logging feature lets you record every injection: the medicine, dose strength, date, and time. When you transition to a new medicine, that log becomes a clean reference point for both you and your prescriber, showing exactly where you were and when the change happened.

The side-effect tracker is equally valuable around a switch. Because starting a new medicine often brings a fresh adjustment period, logging how you feel day to day — nausea, energy, appetite changes — lets you spot patterns and bring something concrete to your next appointment rather than relying on memory. The app also generates a doctor report you can share directly, summarising your logged data in a format that supports a clinical conversation.

For a broader look at Mounjaro and everything involved in managing that medicine, the Mounjaro guide is a good starting point.

Whatever stage you are at — considering a switch, mid-transition, or just settling in — keeping your own records means you stay informed and prepared. GLP Trackr is free to try for 7 days on the App Store and Google Play. Download it and start building a record of your journey from day one of any change.

A note on safety: any decision about changing your medicine, including which dose to start on, must be made with your prescriber. If you experience symptoms that feel severe or persistent after a switch, contact your healthcare professional promptly.