Injectable Weight Loss

Mounjaro vs Wegovy: What’s the Difference?

If you’re exploring prescription options to help with weight loss, you might have heard of Mounjaro and Wegovy.

Both are injectable treatments that can support your journey, but they work a little differently.

How do they work?

Mounjaro works by targeting two hormones in your body—GLP-1 and GIP—which helps reduce your appetite and manage weight more effectively for some people. Wegovy focuses on just one hormone, GLP-1, but it also helps curb hunger and support weight loss.

Both treatments are approved and used alongside healthy eating and more activity — they’re not magic bullets, but they can make a real difference.

Here’s a quick look at the main points:

What’s inside? Mounjaro contains tirzepatide; Wegovy contains semaglutide.

How they work: Mounjaro targets two hormones; Wegovy targets one.

Results: Studies suggest Mounjaro might lead to more weight loss for some, but everyone’s different.

Who can use them? Both are prescribed to adults who are overweight or living with obesity and related health issues.

Not sure which one suits you best? When you speak to your 123meds healthcare professional, they’ll go through your health details and guide you towards the right choice for your lifestyle and goals.

Mounjaro and Wegovy are both effective prescription injections for weight loss, but studies show Mounjaro may lead to greater results.

In clinical trials, people using Mounjaro lost up to 20–22% of their body weight on average, while those on Wegovy saw around 15–17% weight loss.

Both medications work by reducing appetite—Mounjaro targets two hormones (GLP-1 and GIP), and Wegovy targets one (GLP-1).

The results can vary by individual and both are intended to be used alongside a healthy diet and increased physical activity.

Like any medicine, Mounjaro and Wegovy can cause some side effects, but most people find they’re mild and get better after a little while. The most common ones are feeling a bit sick (nausea), tummy upset like diarrhea or constipation, stomach cramps, or headaches.

If you do experience any persistent side effects, or anything worrying like severe pain or fever, please cease the use of your treatment and seek urgent medical advice from your GP or NHS111 to exclude anything serious. 

Your 123meds prescriber can talk you through what to expect and how to handle any side effects so you feel supported all the way.

No, you don’t need to sign up for a subscription. At 123meds, you can order your medication whenever you need it—there’s no commitment to ongoing deliveries unless you choose one. This way, you stay in control and can manage your treatment at your own pace.

If you’d like, we also offer convenient subscription options to help you never run out of your medication, but it’s completely up to you!

The rate and extent of weight loss can vary from person to person - with a number of factors, including genetics and lifestyle influencing this. 

As such, it is difficult to make a precise prediction for an individual as each person responds differently. 

We can look at reviewing your treatment at any stage, if you feel that your weight loss journey is not going to plan. 

Due to the nature of obesity as a condition, weight regain can occur, even with more invasive forms of treatment such as bariatric surgery. 

Weight regain can be limited however, though improving your dietary and lifestyle habits during treatment, to establish positive habits for when you decide to cease treatment.