Key differences between Mounjaro and Wegovy as both go head-to-head in weight loss trial with one clear winner

There are plenty of drugs people are injecting into themselves to help with weight loss, and they've all got weird names.

Ozempic, Wegovy, Mounjaro, and Saxenda all sound like types of cars from a brand name you've never heard of before.

While they are used for similar purposes, namely helping someone lose weight by suppressing their appetite, there are some important differences between each of the jabs and how they appear to be helping people.

A recent study (from the makers of Mounjaro) put 750 obese people with an average weight of 113kg through a 72 week trial to see whether taking different weight loss drugs produced different results.

It found that between Wegovy and Mounjaro one of them appears to be some way more effective at helping people with weight loss.

Some of the people who've taken one of the various drugs on offer and then switched brands have talked about how some of them work for them personally while others don't.

How do they work?

These drugs contain an ingredient that mimics the GLP-1 hormone, which plays a part in regulating your blood sugar and appetite.

It helps the body produce more insulin, slows digestion, and makes a person feel fuller.

If you feel full, the idea is that you'll stop eating, and if you eat less, you'll lose weight.

They all trigger a similar response in the body, but they're not exactly the same (Getty Stock Photo)

Most of these drugs that some people are using for weight loss often started out as prescriptions for Type-2 diabetes.

Indeed, Ozempic is still prescribed in the UK for diabetes and is not something your doctor would prescribe you for weight loss unless they were doing it 'off label'.

The injections of these drugs tend to be done once a week, though another product called Saxenda is a daily injection.

What do they do differently?

They've got different active ingredients in them, so they're not all exactly the same despite them all mimicking the GLP-1 hormone.

For Wegovy and Ozempic, the active ingredient is semaglutide, though Ozempic has less of it and is not prescribed as a weight loss drug, whereas Mounjaro uses something called tirzepatide.

Saxenda, meanwhile, uses liraglutide.

The effects they have on your body and mind vary, as Wegovy flips one appetite switch in your brain, while Mounjaro flips two.

Priority for Mounjaro is given to those with a Body Mass Index of over 30 and have Type 2 diabetes, whereas to get Wegovy on the NHS, you need to have a BMI of 27 or more.

The impact they have on weight loss also seems to vary depending on which drug you take.

Both Wegovy and Ozempic contain semaglutide, but Wegovy has more of it and is the drug you're likely to be prescribed for weight loss (Michael Siluk/UCG/Universal Images Group via Getty Images)

Which one is better for weight loss?

A recent trial between Wegovy and Mounjaro showed how each of the weight loss drugs works over the course of 72 weeks, and it found that Mounjaro was the more effective drug.

This trial was paid for by the manufacturer of Mounjaro, with the results showing that 32 percent of people taking their jab over 72 weeks lost a quarter of their body weight while 16 percent of people on Wegovy lost that much.

Those on Mounjaro also said they lost an average of 18cm off their waistlines, while Wegovy users shed 13cm, and people on Mounjaro also appeared to have better blood pressure, blood sugar and cholesterol levels.

Conducting the trial, Dr Louise Aronne said: "The majority of people with obesity will do just fine with semaglutide (Wegovy), those at the higher end may ultimately do better with tirzepatide (Mounjaro)."

A spokesperson for Novo Nordisk (the manufacturers of Wegovy) told LADbible in a statement: "This study compared the maximum tolerated dose of tirzepatide, a dual GIP and GLP-1 receptor agonist at 10mg and 15 mg, to semaglutide, a GLP-1 receptor agonist at 1.7mg and 2.4mg. 2.4mg is currently the highest approved dose for Wegovy (semaglutide injection).

"In this study the amount of weight loss shown for Wegovy was lower than the amount showed in Novo Nordisk’s registry studies for the medicine, so we are not certain about the study’s methodology.

"We believe that treating obesity is about more than just a number on a scale and Wegovy is the only GLP-1 obesity medication approved to prevent major cardiovascular events such as cardiovascular death, heart attack, and stroke and thereby potentially save and prolong lives."

Mounjaro came out on top in a test to see which one worked better (Sebastian Hidalgo for The Washington Post via Getty Images)

Do they come with side effects?

Yes they do. As the most recognised brand name, Ozempic is copping a lot of the flak with terms such as 'Ozempic mouth' as the visible impact of weight loss shows on various parts of the body.

Losing a lot of weight in a short amount of time is going to have a consequence for your physical appearance.

The drugs carry similar side effects as users have reported problems with nausea, diarrhoea, constipation and abdominal pain.

However, according to Medical News Today, those taking Wegovy might experience fatigue and dizziness, while those on Mounjaro will not.

You should definitely talk to your doctor before you start getting into these drugs and see which one they'd prescribe for you.