They have changed the face – and figure – of the dieting industry in recent years. But which of the weight-loss jabs would you choose – Mounjaro or Wegovy?

These two weight loss heavy hitters, the brand names for the drugs tirzepatide and semaglutide respectively, have come to dominate the UK market.

Online pharmacies Chemist4U and Simple Online Pharmacy estimate that as many as 500,000 people in the UK take either Mounjaro or Wegovy, with Mounjaro winning about a 70 per cent share of sales via online pharmacy prescriptions.

Now, the first head-to-head trial in the UK appears to show that one may help more than the other…

Both Wegovy and Mounjaro work by tricking the brain into making the user feel full so they eat less. Both are usually injected weekly, depending on the dose.

Wegovy – the version of Ozempic licensed for weight loss – mimics the effects of the GLP-1 hormone released by the body after a meal to stop you feeling hungry. Meanwhile Mounjaro triggers two of these receptors in the brain – GLP-1 and GIP receptors.

In the 72-week trial (paid for by Mounjaro’s manufacturer) of 750 obese people with an average weight of 18st, it was found that both drugs led to substantial weight loss. But those taking Mounjaro lost an average of 20 per cent of their weight compared to Wegovy’s 14 per cent.

Presented at the European Congress on Obesity in Malaga and published in the new England Journal of Medicine this month, the findings showed those on Mounjaro lost an average of 18cm from their waistlines compared to 13cm on Wegovy.

Amy Jones, 40, is a plus-sized model and researcher. She lost 17 per cent of her body weight in six months on the weight-loss jab Wegovy 

Nearly a third (32 per cent) of the Mounjaro users lost a quarter of their body weight compared to 16 per cent on Wegovy.

Women tended to lose more weight than men and both had similar levels of side effects such as nausea, constipation and wind.

Dr Louis Aronne, who conducted the trial at the Comprehensive Weight Control Center at Weill Cornell Medicine in New York, 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).’

The Mail found two women in their forties who both had exactly the same BMI of 36.3 when they started their weight loss journey. One chose to take Wegovy while the other chose Mounjaro, and both kept precise diaries. So who lost more after six months and what side effects did they suffer...?

WEGOVY: I LOST 17 PER CENT OF MY BODY WEIGHT IN SIX MONTHS

I was almost 19st and a size 22 and my doctor had warned me that if I didn’t lose weight, there was a good chance I was going to develop diabetes, writes Amy Jones

Amy Jones, 40, is a plus-sized model and researcher. Married to Stephen, 43, a project manager, the couple live in Macclesfield.

INITIAL BMI: 36.3

WEIGHT: 18st, 1lbs

HEIGHT: 5ft 10in

I’ve always been pretty body confident and love representing the larger community as a plus-size model, but by my late thirties, my weight was beginning to affect my health. I was more than 18 stone and a size 22 and my doctor had warned me that if I didn’t lose weight, there was a good chance I was going to develop diabetes. An old back injury flared up and I knew my weight wasn’t helping. Also it was much harder to do any of the activities I wanted to do like running anymore because I was heavier and lacking in energy. 

Stephen and I both decided to try to lose weight and so we began eating healthier and going out for more walks. We bought a Peloton which was absolutely brilliant and started watching our portion control. But felt I needed something more. 

I’d heard all about weight-loss jabs in the news and started researching them online. I really wasn’t sure it was for me, I’d heard that so many people have side effects such as nausea and didn’t want to have ‘Ozempic face’ where you lose too much weight and look gaunt. I wasn’t too certain about the long term effects either. 

WHERE I GOT THE JAB: I did consult my doctor about going on Ozempic but they told me I didn’t qualify. My BMI was over the cut off but I didn’t have a weight-related health condition.

Then I came across a company called Voy who offered weight-loss jabs with a more holistic approach. For £250 a month you were partnered up with a dietician and had a call with them every two weeks and they recommended what dose of jab you would get and how you should eat. They recommended I use a mild dose of Wegovy – the version of Ozempic licensed for weight loss - and I was happy to take their advice. They said if I started off on a very small dose of 0.25mg then I’d be less likely to suffer side effects. I had mild nausea for a few days but that was it.

WEEK ONE WEIGHT LOSS: 0lbs

...I also didn’t lose any weight! Injecting myself in the stomach didn’t faze me, it really didn’t hurt at all, but the jabs didn’t start working immediately and I was warned about that.

Two weeks in, however, I started to notice the ‘food chatter’ was gone from my brain. I’ve always been the kind of person who is thinking about their next meal, their next snack, what is in the fridge. With that gone, it so much easier to plan healthy, nutritious meals and I didn’t have a constant fight with my brain to grab a biscuit. It helped that I had a fortnightly online consultation with a nutritionist. I had been sceptical about this at first, thinking they would be judgemental. But she helped me plan meals and gave me tips such as only have a tonic water without the gin to ‘break’ the habit of drinking.

I started eating healthier things like yoghurt and fruit for breakfast, a poached egg on toast or salad for lunch, then something like a curry with rice or a pasta dish in the evening. I found I needed something more carby in the evenings because that’s when I was doing my exercise, taking up running again.

MONTH ONE WEIGHT LOSS: 0lbs

Nothing happened weight-wise for four weeks but I was still comfortable with this because I’d been told it was likely. It was only when I went up to 0.5mg that the weight started coming off. By week eight, I had increased the dose to 1mg of Wegovy, and by week ten, I’d lost 1st 8lbs in just those six weeks from starting on the 0.5 dose. 

COST: over £1000 

Financially it’s cost me more than £1000 which is no small amount as I’m not a rich person and that did worry me. But I reasoned that while I was buying the jabs, I was spending far less money on food.

Amy has now been on the jabs for two years and in total have lost 6st 4lbs. She is down to a size 16 dress and weigh just under 12 stone

SIDE EFFECTS: Tapering up so slowly meant I avoided the worst ones. It’s certainly had an effect on my drinking though – the impulse to drink alcohol, especially when I’m bored, has vanished.

I am still able to do the plus size modelling but I've built more muscle, Amy writes

SIX MONTH WEIGHT LOSS: 3st 1lbs (17 per cent of total body weight)

AVERAGE WEEKLY WEIGHT LOSS: 1.7lbs

WEIGHT AFTER SIX MONTHS: 15st

BMI AFTER SIX MONTHS: 30.1

In six months I’d lost 43lbs – but I kept on going. I’ve now been on the jabs for two years and in total have lost 6st 4lbs. I’m down to a size 16 dress and weigh just under 12st, with a BMI of 24.

I want to lose just a few more pounds before I come off the jabs entirely to get wholly into the healthy BMI range.

I am still able to do the plus size modelling which I love as I still have my hourglass shape and don’t want to lose that, but I’ve built more muscle (plus-sized is considered anything over a size 12).

I’m not nervous about stopping them as I feel like the Wegovy has retrained my brain to know the difference between real hunger and hunger where you’re just thinking about food.

Stephen has also lost around six stone alongside me but simply through will power - thanks to healthy eating and football.

MOUNJARO: I LOST 57lbs IN SIX MONTHS - A WHOPPING 27 PER CENT OF MY BODY WEIGHT

After I had my son two years ago, I ballooned in weight going up to 13st 10lbs and wearing size 16-18. I’m only 5ft 1in, so I was heavy and my confidence was massively impacted, Nicola Donnelly writes

Nicola Donnelly, 43, owns her own accountancy business. She lives in Liverpool and has three children, Elle, 26, Mikey, 24 and Gray, who is two. She started on Mounjaro last November and has lost over 4st already.

INITIAL BMI: 36.3

STARTING WEIGHT: 13st 10lbs

HEIGHT: 5ft 1in

After I had my son two years ago, I ballooned in weight going up to 13st 10lbs and wearing size 16-18. I’m only 5ft 1in, so I was heavy and my confidence was massively impacted.

My marriage ended last July, which just added to the stress and I became more and more depressed.

My mum had a friend at work who had lost a lot of weight using Mounjaro and said I should try it, but I was really against any kind of weight-loss jab. I don’t even like taking paracetamol because I just feel that medication isn’t good for the body – but at that weight, I knew I had to do something. I did some research, and the more I read up about it, the more I realised it might actually work for me – and in fact make me much healthier.

WHERE I GOT THE JAB: I never even considered going to my GP but decided to order a 2.5mg pen for just over £100 in November from an online pharmacy. I had to fill out a long questionnaire about my health and send in pictures to prove I was as big as I said I was. Then they had to send it to my GP who could verify my answers. It took about two weeks for the first batch to arrive (probably because of the time it took for my GP to verify) but after that, doses would arrive in a couple of days.

Because I’m terrified of needles my mum had to come around and inject me the first time while I stood there and winced and closed my eyes! After the first few times, I was able to do it myself. Now I can do it without thinking.

WEEK ONE WEIGHT LOSS: 4lbs

I felt the appetite suppression straight away. My problem has never been eating unhealthy food or takeaways, but my portions were out of control and I’d be eating at all hours. Because I run my own business, some days I could be at the laptop at 2am eating a large bowl of pasta or eggs on toast. And I hate waste. I’d always clean the plate.

But suddenly, I didn’t want a full plate. I still don’t and will only make myself a child-size portion, which is perfectly satisfying. In that first week I lost 4lbs.

By the end of the first month, Nicola had already lost 9lbs and now plans to taper her dose down 

MONTH ONE LOSS: 9lbs

By the end of the first month, I was already 9lbs down. I went up to a 5mg dose a month later and lost another 9lbs – then 7.5mg, but that was so strong, I could barely eat half a yoghurt because I simply wasn’t hungry, so I went back down to 5mg.

As the appetite suppression wore off over the next few weeks, I eventually went up to 10mg, which I’m on now. I plan to taper back down again.

COST: £700. Although I paid full price for the first couple of pens, I was able to get others much cheaper as I got a special discount code from one of the online providers.

SIDE EFFECTS: The smell and thought of fatty food makes me feel nauseous – I can’t walk into places like KFC now because it makes me feel so sick. And sometimes I feel a little bit tired and disorientated, but that’s more to do with the lack of food I’m eating rather than the Mounjaro. I now have to have an app on my phone to remind me to eat!

Another welcome side effect is that I don’t want alcohol anymore. I used to be able to get through a bottle of wine to myself on a Friday evening when my son was at his father’s house. But now I can’t bear a glass of wine near my mouth because it would make me feel sick. I will have the odd gin and lemonade but even then, I’m not too bothered about it.

My confidence has soared. I was on the floor with depression when I split up with my husband. Now I feel like me again, says Nicola

It made me realise that I don’t want to spend my nights going out and drinking. I want to be able to get healthy and improve myself.

SIX MONTH WEIGHT LOSS: 4st, 1lbs (27 per cent of total body weight)

AVERAGE LOSS PER WEEK: 2.2lbs

WEIGHT AFTER SIX MONTHS: 9st, 9lbs

BMI AFTER SIX MONTHS: 25.5

After losing another 9lbs in the third month, the weight loss slowed down but never to less than 6lbs in a month, and now I am 9st 9lbs.

My target weight was actually 10st but as my BMI is still over 25, I’m going to keep going until I’m 9st.

I’m really nervous about coming off it though and will taper down slowly. I’ve read posts on forums saying people have piled on 8lbs in a week when they’ve come off it because their appetite has stormed back and that’s my nightmare. So I’ll do it slowly. The providers are strict about who can order it, so I won’t just be able to order a new pen if my BMI is below 30.

I’m also using my hand weights and going on the treadmill every night so hoping that will build up muscle and fitness. One of my main reasons for losing this weight was to become as healthy as possible and be around for as long as possible for my children.

My confidence has soared. I was on the floor with depression when I split up with my husband. Now I feel like me again.