Tomorrow evening, just as she has done for the last eight months, Sarah Masterman* will take a small syringe into her 13-year-old daughter Bella's bedroom and swiftly inject medication into one of her thighs.

The mother of three is happy to describe this weekly ritual as little short of a lifesaver, although it is not vital emergency medicine that Sarah is administering to her young daughter's body. It is the GLP-1 drug semaglutide, a weight-loss aid better known by brand names such as Ozempic and Wegovy. Teenage Bella is certainly a success story on that front: since Christmas, she has lost three stone, dropping from 11st 7lbs to just over 8st.

While taking the medication, courtesy of the first private clinic in the UK to offer this service to children, she has transformed from an overweight and deeply unhappy girl, who was bullied for her appearance, to one who is slender and full of confidence.

The drug is working where traditional dieting failed – which is why Sarah has decided to tell her story, in part to offer hope to other parents of children struggling with their weight, but also to pre-empt the inevitable critics who will accuse her of taking the easy way out. The only reason she has chosen not to be identified is to protect her daughter.

'I know people will say, "Well, she's lost three stone in seven or eight months, she could have lost that herself on the right diet and exercise plan."

'Perhaps, but she would probably have put it all back on again,' says Sarah. 'We didn't use this as a quick fix, but as a reset button in conjunction with a healthy diet and exercise to get my daughter where she needed to be after years of unhappiness.'

Bella is one of the first adolescents to be treated privately with GLP-1 weight-loss medications in the UK as a patient at the Manchester-based clinic Diet UK – a highly controversial move that has as many advocates as dissenters.

While it has been prescribed to under-18s in controlled, specialist NHS settings under ongoing tightly controlled clinical trials, Diet UK has become the first clinic in the country to be granted a Care Quality Commission licence to treat adolescents privately with Wegovy, which is approved by the European Medicines Agency for use in children aged 12 and above who are classed as obese.

That means their BMI is at or above the 95th percentile for their age and sex – a healthy weight result is between the 3rd and 91st centile. (Children's BMIs are measured differently to account for the fact their bodies are still growing.) Bella's BMI was above the 99th percentile.

Diet UK claims to have successfully treated 12 patients to date.

'So far all have responded well and the children and parents are delighted,' says a spokesperson for the clinic. 'We are currently getting around 100 enquiries a week, and this number is increasing rapidly every day.'

Statistics suggest there may be no shortage of demand in future: recent research undertaken at universities and hospitals in Bristol and Liverpool shows the proportion of adolescents classified as obese or overweight in England has increased by a shocking 50 per cent overall between 2008 and 2023. Between 2008 and 2010, the figure was 22 per cent, whereas between 2021 and 2023 it was up to 33 per cent.

Numerous long-standing studies, meanwhile, have revealed how being overweight during childhood increases the risk of diabetes and liver disease, among other conditions, later in life.

Nonetheless, some will still question the wisdom of prescribing to teenagers hormone-based drugs which still lack long-term data and for which side-effects, among them pancreatitis, are still emerging.

Sarah understands this concern, although says that, like any issue, the risks have to be weighed in the round.

At just over 5 ft, Bella was in the highest 1 per cent in the 'young person's centile' – the way BMI is measured for adolescents – which classified her at the top end of the overweight range.

More worryingly, according to Sarah, were the psychological effects of her daughter's weight: bullied at school, she had started to self-harm, a desperately concerning development for her parents who began to worry about what Bella's future held.

'We didn't go into this lightly, and of course we looked at side-effects and risks and studied them at length as well as having long discussions with our doctor,' she says. 'The reality is that we had a very unhappy daughter, and we had to do what felt right at that moment.

'The fact that Bella had been self-harming also had profound consequences for her future and we had to balance that against the possible issues with Wegovy.'

Sarah, 50, would also be the first to say she would never have remotely envisaged Bella as a candidate for Wegovy. 'For a long time I was the one with weight issues in our family,' she says.

Married to Jason, a builder, with whom she has two step children, the Yorkshire-based secretary for an engineering company battled bulimia for years and was determined her own daughter would not fall into the same destructive cycles that blighted much of her teen and adult years.

'From 12 onwards, I started a regime of laxatives, starvation, binge eating, which pretty much continued until I was in my 30s,' she recalls. 'There were a lot of years battling with diets, battling with every diet pill you could get – and it was the last thing I wanted for my own daughter.'

So when Sarah became pregnant with Bella in her late 30s, she was determined her baby would not inherit her issues.

'From the moment she was weaned, I gave her healthy homemade food – I didn't buy a single pot of baby food,' she recalls. 'Everything was cooked from fresh.'

Bella grew into 'a very pretty, curly-haired, boisterous, confident little girl' – that is, until around her 10th birthday, when she started developing curves after starting her period.

'She had a couple of very close friends who started making fun of her,' Sarah says. 'Looking back, it was probably jealousy, and at first I put it down to a bit of banter.'

As the weeks went on, however, Bella became more withdrawn.

'She was spending more time in her bedroom, and becoming quite abrupt and belligerent. She wouldn't have her photo taken, refused to take off her hoodie and, on the rare occasion we did get her out, she refused to meet people's eye.'

Over time, Sarah also became aware of her daughter getting up in the night and raiding the kitchen, in particular hoarding the fast food that had crept into the weekly shop over the years.

'Like any busy working parent, I'd dropped the ball when it came to healthy eating and was guilty of buying treat foods and pizzas, stuff that was easy,' she says.

'I didn't realise at first, but I noticed that things were going missing – if we bought a pack of biscuits or crisps they would disappear and then I would find the packets down the side of her bed.'

Like any parent, Sarah tried to talk to her daughter, only to be met with endless stonewalling.

'I saw so many reflections of myself as a child in her, and told her I knew what she was going through, but I couldn't get through to her. She was shouting at me, saying, "Are you calling me fat?", screaming that she hated me whenever I tried to talk to her.'

While the bullying started in primary school, it got considerably worse when Bella started at secondary school.

A desperate Sarah and Jason tried to instigate regular family meals and book activities for their once physically active daughter.

'She wouldn't participate in anything,' she says. 'We bought her a bike, but she wouldn't go out on it. We sent her on a school activity holiday, and she came back completely miserable.'

What Sarah now knows is that, in tandem, her daughter was watching 'body positive' YouTube and TikTok videos which celebrated fuller figures.

'Psychologically it was her way of saying: "Well if they are saying I'm fat, I'm going to embrace it."'

The result was that by the time her 12th birthday came round last April, Bella's weight had ballooned to well over 11st, and she was now being severely bullied at school.

'It was awful to see her so upset,' Sarah says, the emotion evident in her voice.

'She just wasn't the happy little girl I'd raised. And part of me felt that I was responsible, because we had dropped the ball. I'd been so busy with work, as had my husband. I felt we should have recognised the issues earlier.'

What Sarah was determined to do was ensure that crash diets were not the answer. 'I've been there myself so many times. It's a rollercoaster that only brings you down in the end,' she says.

'So I sat down with Bella and told her I wasn't going to put her on a diet, but that we were going to make some changes as a family.

'I explained to her that the food she was putting in her body wasn't just making her put on weight, but was affecting everything – it was making her skin dry, her hair brittle. So we were going to change that, but it wasn't something that was going to be rushed.'

What that meant was clearing the cupboards of processed foods, buying fresh fruit and vegetables and cooking from scratch.

'I said we were going to lead by example, and that the whole family would start to eat differently.

'We bought new cookbooks, a blender, and we set about cooking meals from fresh like we did when she was little,' says Sarah. Determined to avoid what she calls 'the tyranny of the scales', Sarah also told Bella that instead of weighing her, they would document her progress with regular photographs.

Initially, Bella embraced the process, yet progress proved frustratingly slow. 'In seven months she had only lost half a stone,' Sarah recalls. 'We noticed that she was reverting back emotionally, withdrawing from us.'

Moreover, when Sarah talked to her daughter, Bella confided that she was being bullied again.

'She had been called a fat pig, and on another occasion she had walked into a classroom, and someone had said they were going to need an extra chair,' says Sarah.

Things came to a head at the end of November when a devastated Sarah discovered that Bella was self-harming.

'She'd refused to take off her hoodie. When I asked her what was going on and insisted she removed it, she started crying and then took it off – at which point I could see cuts on her arms from her shoulders down to her wrists. She said she was fat and ugly and she hated herself,' Sarah's voice wobbles.

'I felt almost physically sick at the extent of her unhappiness. It's your worst nightmare as a parent.'

As Sarah and Jason wrestled with what to do, an email arrived from Diet UK to say they had been licensed to give GLP-1 to adolescents under certain circumstances.

Sarah was on the company's mailing list having previously worked with the clinic to lose weight herself.

'I wasn't using weight-loss injections, but I benefited from their structured healthy eating programme, and I was impressed with their holistic approach,' she says.

And while the idea that weight-loss injections could be prescribed to under-16s was news to her, she was immediately interested.

'It wasn't just the injection itself, but the support mechanism that's behind it helping you understand how to eat better. I didn't remotely see it as a quick fix, but I felt we needed to try something new.' When she discussed it with Bella, she was surprised to find her daughter felt the same way.

'She said she felt she had tried so hard and nothing else was working,' she says.

After a conversation with Diet UK's founder Dr Sindy Newman, in which it was decreed that Bella's weight – 11st 7lbs and waist size of 80cm – meant she may be eligible, Bella had a one-on-one consultation with Dr Newman in which Sarah was allowed to listen in.

'What I found interesting was that Dr Newman didn't talk to Bella about weight or size, but in more general terms about what she thought about her appearance, whether she compared herself with others, and did she often get tired. It was focused more on her well-being,' Sarah recalls.

At a subsequent online meeting, Sarah was told that Bella was considered a good candidate for Wegovy, and mother and daughter were given a prescription for a 0.25 mg – the lowest prescription – to be administered once a week. Bella would also have regular consultations to monitor her health and mood.

'Dr Newman said Bella would feel bloated at first because the food would last longer in her stomach,' she says. 'She told her to drink plenty of water, to eat protein for breakfast and avoid high-sugar foods. She also told her she might feel tired and nauseous.'

Diet UK does not prescribe a target weight for its young patients as they are still growing, so the recommended target weights will change all the time.

It didn't come cheap: after the initial £50 30-minute consultation, Sarah pays £190 a month for her daughter's Wegovy prescription and the clinic's round-the-clock support. 'We have to budget for it, but I would pay whatever it took to help get my daughter back,' says Sarah.

And so, the week before Christmas, Sarah administered the first dose into her daughter's thigh, which she had been told by Dr Newman was the most effective place to inject. 'Bella took it in her stride,' she says.

To Sarah's relief, there were no obvious side-effects, although Bella did complain of tiredness and also of feeling sick, as Dr Newman had warned.

'She drank lots of water and got through it,' she says. 'Since then, there's been nothing noticeable at all.'

That is – apart from the impact on her daughter's appetite. 'From early on, she just wasn't particularly hungry,' Sarah says. 'At one point she opened a bar of chocolate, took one bite and said she didn't fancy the rest.'

What's more, within a week of the first injection, Bella expressed an interest in preparing her own meals, from omelettes for breakfast to home-made pasta sauces for dinner.

'I noticed after Christmas she started getting a little bit more energy too,' Sarah says. 'She wasn't as tired when she started the injections either. And she started getting into making her own food.'

As 2025 unfolded, Bella's weight started to drop off. 'But what was wonderful was that her skin and her hair started changing too. Her skin started to glow, her hair lost its brittleness,' says Sarah.

Seven months after she started, Bella now weighs just over 8st, and is preparing to come off the weight-loss drug with an individually tailored maintenance programme provided by the clinic encouraging a balanced lifestyle.

She has also taken up running, and wants to join a rugby team.

Bella elected not to tell school friends that she was taking the jabs, fearing it might mean the bullying got worse. She now feels confident enough in her new lifestyle to come off the medication.

'She's now at the point where she is happy and it's not just because she's lost weight, but because she feels confident in her skin and understands how what you eat affects your mood,' says Sarah.

'The way I look at it is you cannot put a price on what has happened to Bella.

'This week we went shopping for our summer holiday and I watched her trying on swimming costumes and shorts, all things she wouldn't have gone near last year,' she smiles. 'As I watched her skipping in and out of the changing room so happy and excited, I realised I'd got my daughter back.'

Names and identifying details have been changed

Additional reporting: Matthew Barbour