Wegovy vs Mounjaro: The main differences

In our “vs” blog series, we provide information about the most important differences between common weight loss injections and tablets. In this blog, you will find a detailed comparison between Wegovy and Mounjaro.

What are the main differences between Wegovy and Mounjaro?

The active ingredients in Wegovy and Mounjaro reduce hunger and help people lose weight over time. Both medications are injected under the skin using a pre-filled pen – but follow different approaches. While Wegovy is based on the well-known active ingredient semaglutide (which is also found in Ozempic), Mounjaro contains tirzepatide, a combination of two mechanisms of action. Like Wegovy, it mimics the naturally occurring gut hormone GLP-1 (glucagon-like peptide-1) and additionally the hormone GIP (glucose-dependent insulinotropic polypeptide), which in studies has shown even stronger effects on weight and blood sugar than Wegovy.

How do Wegovy and Mounjaro work?

Wegovy:

The active ingredient semaglutide acts as a so-called GLP-1 receptor agonist, meaning it mimics the GLP-1 hormone produced in the gut. It

regulates the feeling of satiety in the brain,
delays gastric emptying and
stimulates insulin secretion.

This leads to

less hunger,
lower food intake, and
continuous weight loss.

Mounjaro:

Tirzepatide is a so-called dual agonist that mimics two hormones:

GLP-1: as with Wegovy – promotes satiety and insulin.
GIP (glucose-dependent insulinotropic polypeptide): further supports glucose metabolism.

Who is Wegovy suitable for – and who is Mounjaro for?

Wegovy is approved in the EU for the treatment of obesity. It is used for individuals 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 the treatment of obesity (BMI of at least 30) and overweight (BMI between 27 and 30 with comorbidities) as well as type 2 diabetes.

Switching between medications

Important to consider: Uninterrupted switching is not recommended

Both Wegovy and Mounjaro are approved in the EU for the treatment of obesity – with a BMI ≥ 30 or BMI ≥ 27 with comorbidities such as high blood pressure or type 2 diabetes. This means: A switch is generally possible, but should only be done after consulting a physician and may not be seamless. For example, there are no manufacturer guidelines 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 be beneficial depending on individual response to the active ingredient or if the desired effect is not achieved.

Possible reasons to switch:

Insufficient weight loss despite correct use.
Intolerances or side effects.
Desire for a different mechanism of action (GLP-1 vs. GLP-1/GIP).

Mounjaro is a dual agonist that has shown potentially stronger effects on weight and blood sugar in studies. Switching should always take place under medical supervision – especially since the dosage regimens and potential side effects differ.

Expected weight loss: Wegovy vs Mounjaro

According to clinical studies, the following weight loss is possible:

With Wegovy – depending on initial weight and lifestyle – a weight loss of 15% or more within 12–18 months may be achievable.
With Mounjaro, weight loss can be up to 22.5% depending on dosage.

However, success also always depends on diet, exercise, and comorbidities.

Summary: Wegovy vs Mounjaro

Two modern medications with different mechanisms of action:

Wegovy: GLP-1 agonist, approved in Germany for medical weight loss in cases of overweight or obesity.
Mounjaro: Dual GIP/GLP-1 agonist – approved for medical weight loss in cases of overweight or obesity and for the treatment of type 2 diabetes.
Both medications are prescription-only and should only be used under medical supervision.

Note: This article is for informational purposes only and does not replace medical advice.

Sources:

EMA product information on Wegovy and Mounjaro: