Is Mounjaro the Same as Wegovy?

The core difference between Mounjaro and Wegovy comes down to their active substances and the pathways they act on.

Active substances

• Mounjaro — active substance tirzepatide. It acts on two receptors: GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). This dual action is what distinguishes it from other medicines in this class.
• Wegovy — active substance semaglutide. It acts on the GLP-1 receptor only. Semaglutide is also the active substance in Ozempic, though Ozempic is a separate product at different dose strengths — if you are curious about that distinction, see how Wegovy and Ozempic compare.

How they work

Both medicines act on appetite-regulating pathways. GLP-1 receptor activation is commonly associated with increased feelings of fullness, reduced appetite, and slower gastric emptying — an effect that often lessens over time as the body adjusts. Mounjaro's additional action on GIP receptors is part of what makes it a distinct medicine, though the clinical significance of that difference for any one person is something their prescriber is best placed to explain. For a fuller look at the mechanism, see how Mounjaro works.

Are the dose strengths the same?

No. Mounjaro is typically available in strengths such as 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. Wegovy is typically available in strengths such as 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, and 2.4 mg. The numbers are not interchangeable — they reflect different compounds at different scales. Dose schedules for both are set and adjusted by a prescriber.

Is metformin the same as Wegovy?

No — metformin is an entirely different type of medicine. It is an oral tablet used in the management of type 2 diabetes and works through a different mechanism altogether. Wegovy (semaglutide) is an injectable GLP-1 receptor agonist. The two medicines are not related, though some people may be prescribed both. Any questions about medicines you take alongside Wegovy or Mounjaro are best directed to your prescriber or pharmacist. It is also worth knowing that Mounjaro is similarly unrelated to Ozempic in formulation, even though both involve GLP-1 pathways — you can read more about whether Mounjaro and Ozempic are the same.

Both Mounjaro and Wegovy carry a black triangle (▼) designation, meaning they are subject to additional monitoring. Any side effects should be reported to your healthcare professional and, where applicable, to your national reporting scheme (such as the UK's Yellow Card scheme).

GLP Trackr is built to support people already prescribed either Mounjaro or Wegovy — the app works the same way regardless of which medicine your prescriber has given you.

Because both are once-weekly injections, one of the most practical features is dose and injection logging: you can record each injection with its date, dose strength, and site (abdomen, thigh, or upper arm), and the app tracks your rotation history to suggest your next site. This is especially useful in the early weeks of treatment when the routine is still becoming habit.

The app also includes a side-effect tracker, so if you notice nausea, fatigue, or other commonly reported effects, you can log them over time and see whether patterns emerge — a useful record to bring to your next prescriber appointment rather than trying to recall details from memory. For context on how Mounjaro and other GLP-1 medicines interact with other treatments, you may also find it helpful to read about taking Mounjaro alongside orlistat.

If you ever have questions about which medicine you have been prescribed, why your prescriber chose it, or whether a switch might be appropriate, those are conversations to have directly with your healthcare professional — GLP Trackr is a tracking companion, not a substitute for clinical advice.

Log your doses, track your side effects, and bring clearer data to your next appointment. GLP Trackr is available free on the App Store and Google Play, with a 7-day trial to get started.