Mounjaro® vs Wegovy®

Reviewed by Dr Mitra Dutt

Mounjaro® and Wegovy® are both weight loss treatments. Both medications are weekly injections. They work by:

• Suppressing your appetite
• Making you feel fuller for longer
• Slowing down the rate that food leaves your stomach. 

Are Mounjaro® and Wegovy® the same?

Although Mounjaro® and Wegovy® work in similar ways, they are not the same. The key differences are mentioned below. 

Active ingredients

The active ingredient in Mounjaro® is called tirzepatide. This ingredient activates two hormonal receptors (GIP and GLP-1). When these hormones are mimicked, your appetite is suppressed, blood sugar is better regulated, and the rate of food leaving the stomach is slowed down. All of these actions result in weight loss.

The active ingredient in Wegovy® is called semaglutide. This works by mimicking the hormonal receptor GLP-1, resulting in the same actions mentioned above. However, Wegovy® does not mimic GIP.

Dosages

As well as the active ingredients, the dosages are different. On Wegovy®, you can expect to start on a dosage of 0.25mg. It then goes up in increments until a maintenance dose of 2.4mg is reached.

When taking Mounjaro®, your starting dose is 2.5mg. This then goes up in 2.5mg increments until a dose of 15mg is reached – this is called the maintenance dose. 

Manufacturers

The drugs have different manufacturers. Wegovy® is made by the Danish pharmaceutical company, Novo Nordisk. Mounjaro® is manufactured by the North American company, Eli Lilly.

Is Mounjaro® better than Wegovy®?

Mounjaro® is more effective than Wegovy®. A clinical trial over a 72-week period showed that 96% of the participants taking Mounjaro® (on the highest dose) lost 5% or more of their starting body weight. In a similar trial, 84% of people taking Wegovy® on the highest dose lost at least 5% of their body weight.

Can you switch from Wegovy® to Mounjaro®?

Although the data shows that Mounjaro® is more effective, this does not mean you should switch without thinking it through.

If you have been on Wegovy® for some time, and are tolerating the side effects, it might be worth staying on your Wegovy® journey, especially if you are seeing good results. If prescribed by LloydsPharmacy Online Doctor, send us a message in your account if you’re thinking of switching and need some advice. If you are not a patient with us, we can help you make the switch (if clinically appropriate) or support you on your current Wegovy® journey. You will also need to complete a weight loss consultation.

How to switch from Wegovy® to Mounjaro®

You must not take Wegovy® and Mounjaro® at the same time. Doing this can cause serious side effects. There is no benefit of taking both at the same time. If you do switch, you will need to take your first Mounjaro® injection at least one week after your last Wegovy® injection.

If you would like to switch with LloydsPharmacy Online Doctor, and are an existing patient, you will need to complete another weight loss consultation.

If prescribed elsewhere, we can help you make the switch to Mounjaro® (if clinically appropriate), or you can continue your Wegovy® journey with us on your current dose. 

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References

https://www.novonordisk.com/
https://www.lilly.com/
https://clinicaltrials.gov/study/NCT04184622?tab=results#results-overview
https://www.ema.europa.eu/en/documents/overview/Wegovy®-epar-medicine-overview_en.pdf