In our “vs” blog series, we explain the key differences between commonly used weight loss injections and tablets. This article provides a clear overview of Wegovy vs Mounjaro. We focus on how they work, EU approval, target groups, and the Wegovy Mounjaro differences in everyday clinical practice.
If you would like an initial overview of medical options, the page Weight loss medication options can be a helpful starting point.
What are the main differences between Wegovy and Mounjaro?
The active ingredients in Wegovy and Mounjaro reduce appetite and may support weight loss over time. Both medications are injected under the skin using a prefilled pen, but they follow different approaches.
While Wegovy is based on the active ingredient Semaglutide, Mounjaro contains Tirzepatide, which combines two mechanisms of action. Like Wegovy, it mimics the naturally occurring gut hormone GLP-1 (glucagon-like peptide-1) and also the hormone GIP (glucose-dependent insulinotropic polypeptide). In studies, this has been associated with somewhat stronger effects on weight and blood sugar than Semaglutide.
How do Wegovy and Mounjaro work?
Wegovy: GLP-1 receptor agonist (Semaglutide)
The active ingredient Semaglutide acts as a GLP-1 receptor agonist. It mimics the hormone GLP-1, which is produced in the gut. This may:
- regulate satiety signals in the brain,
- slow stomach emptying, and
- support insulin release.
This may lead to:
- less hunger,
- lower food intake, and
- steady weight loss.
For a concise overview of eligibility and the treatment pathway, see Wegovy (Semaglutide).
Mounjaro: dual agonist (Tirzepatide)
Tirzepatide is a dual agonist that mimics two hormones:
- GLP-1: promotes satiety and supports insulin regulation.
- GIP (glucose-dependent insulinotropic polypeptide): also supports glucose metabolism.
More details about treatment can be found under Mounjaro (Tirzepatide).
Who is Wegovy for, and who is Mounjaro for?
Wegovy is approved in the EU for the treatment of obesity. It is used for people with a BMI of at least 30, or a BMI between 27 and 30 with comorbidities such as high blood pressure, insulin resistance, or sleep apnea.
Mounjaro is approved in the EU for obesity (BMI at least 30) and overweight (BMI between 27 and 30 with comorbidities). It is also approved for type 2 diabetes.
Wegovy or Mounjaro: comparison at a glance
| Criterion | Wegovy | Mounjaro |
|---|---|---|
| Active ingredient | Semaglutide | Tirzepatide |
| Mechanism of action | GLP-1 receptor agonist | Dual agonist: GLP-1 and GIP |
| Administration | Injection with a prefilled pen | Injection with a prefilled pen |
| EU approval | Obesity and overweight with comorbidities | Obesity and overweight with comorbidities, plus type 2 diabetes |
| Expected weight loss in studies | often around 15% or more (depending on baseline) | depending on dose, in some studies up to around 22.5% |
Switching between medications
Important to know: a seamless switch is not recommended
Switching between Wegovy and Mounjaro may be possible, but it should only be done after medical advice. In addition, a switch cannot always happen without interruption. For example, there are no manufacturer instructions or studies on switching from Wegovy to a higher dose of Mounjaro.
Pros and cons of switching
Switching from Wegovy to Mounjaro, or vice versa, may make sense depending on how someone responds to the medication or if the desired effect does not occur.
Possible reasons for switching:
- Insufficient weight loss despite correct use.
- Intolerance or side effects.
- Preference for a different mechanism of action (GLP-1 versus GLP-1/GIP).
Because dosing schedules and potential side effects can differ, any switch should always take place under medical supervision. A clear overview of the treatment process and common side effects is provided in Therapy process and side effects before you start.
Expected weight loss: Wegovy vs Mounjaro
Based on clinical studies, the following ranges may be possible:
- With Wegovy, depending on starting weight and lifestyle, a weight loss of 15% or more may be possible within 12–18 months.
- With Mounjaro, weight loss may be up to 22.5%, depending on the dose.
Results also depend on diet, physical activity, and comorbidities.
More comparisons at a glance
If you want to compare options beyond Wegovy vs Mounjaro, this overview may help. Depending on your focus, mechanism of action, EU approval, and administration are often most relevant.
| Comparison | What is it about? | Link |
|---|---|---|
| Wegovy vs Ozempic | Semaglutide in two products: EU approval and target groups compared | Wegovy vs Ozempic: the main differences |
| Mounjaro vs Ozempic | Tirzepatide vs Semaglutide: differences in mechanism of action and indications | Mounjaro vs Ozempic: the main differences |
| Wegovy vs Saxenda | GLP-1 compared: administration and practical differences in treatment | Wegovy vs Saxenda: the main differences |
Summary: Wegovy vs Mounjaro
Two modern medications with different mechanisms of action:
- Wegovy: a GLP-1 agonist (Semaglutide), approved in Germany for medical weight loss in people who are overweight or have obesity.
- Mounjaro: a dual GIP/GLP-1 agonist (Tirzepatide), approved for medical weight loss in people who are overweight or have obesity and for the treatment of type 2 diabetes.
- Both medications are prescription-only and should be used only under medical supervision.
If you want to clarify whether Wegovy or Mounjaro could be an option for you, a medical assessment can be arranged via Book an appointment.
Note: This article is for information only and does not replace medical advice.
Sources
- Wilding, J.P.H. et al. 2021. Once-Weekly Semaglutide in Adults with Overweight or Obesity. The New England Journal of Medicine.
- Jastreboff, A. M., et al. 2022. Tirzepatide Once Weekly for the Treatment of Obesity. The New England Journal of Medicine.
- Gelbe Liste. 30.07.2021. GLP-1 receptor agonists (incretin mimetics).
- Pharmazeutische Zeitung. 21.07.2021. Tirzepatide – a promising antidiabetic medication.
EMA product information for Wegovy and Mounjaro: