Mum who lost seven stone on Mounjaro issues urgent health warning after ‘vomiting brown liquid’

A 21-stone mother claims she used skinny jabs to get ‘healthy’ – only for her daughter, eight, to have to call an ambulance when her liver ‘failed’ and she got sepsis.

Nikki Cuthbertson, from Stoke-on-Trent, Staffordshire, feared being so overweight would see her have a heart attack and die young so started using Mounjaro in November 2024.

The 34-year-old ordered the £150 jab from an online pharmacy and started losing weight every week, dropping a whopping seven stone by July 2025 and increasing her dose to 15mg.

The family of drugs known as GLP-1 RAs, originally developed to treat diabetes, are now often being used for weight loss as they were found to suppress a patient’s appetite.

Mother of three Nikki started having chest pains in June but put it down to trapped wind and was told nothing was wrong when she went to hospital.

But a month later, Nikki said the pain became ‘worse than labour’ and she started vomiting ‘brown’ liquid, having to be rushed to Royal Stoke University Hospital.

The mum-of-three feared she would die when an ultrasound and an MRI scan revealed her liver was inflamed and that she was suffering from sepsis.

Nikki was forced to have surgery to remove her gallbladder, leaving her hospitalised for five days.

Mounjaro’s information leaflet warns that gallstones are a ‘common’ side effect of the medication and may affect ‘up to one in 10 people’, while infection of the gallbladder may affect one in 100.

Lilly, who manufacture Mounjaro, said patient safety is a ‘top priority’ and they ‘encourage patients to consult their doctor about any possible side effects they may be experiencing’.

Nikki said: ‘I was terrified I would have a heart attack and die [due to my weight].

‘I’m a single parent with three children and I’m going to leave them without a parent. I thought, ‘I can’t do this anymore, I’m basically killing myself.’

‘I started Mounjaro and it was fantastic from there. I was so heavy that the pros outweighed the cons.

‘I would rather end up with pancreatitis than a stroke or a heart attack. I was aware.

‘I lost weight every week. It was brilliant. It wasn’t like I was on a diet, it’s hard not to be on a calorie deficit when you’re on it.

‘I started with 2.5mg and went up to 15mg. I absolutely loved it.

‘I started having this pain in June, I convinced myself it was a heart attack so I went to hospital but there was nothing wrong with my heart.

‘I travelled abroad and struggled a bit when I was there. In July, on a Sunday night, it got real. The pain was unbearable.

‘It was underneath my chest it felt like someone was sitting on me. It was worse than labour.

‘By Monday morning I was vomiting, I was really ill, the sick was brown. My daughter rang me an ambulance, she is eight.

‘They took me to the surgical ward and had an ultrasound which showed inflammation and stones. I had an MRI scan and I had [laparoscopic cholecystectomy] surgery [to remove the gallbladder] the next morning.

‘I thought I was going to die when I went to hospital. I was still in pain after they gave me morphine, I was just violently sick.

‘My liver was failing because there was nothing there.

‘I got sepsis because I left it so long, but I had convinced myself it was trapped wind. It wasn’t, I was very poorly.

‘My daughter said I was a bit yellow because my liver was dying.’

The carer said she planned to get a gastric sleeve surgery in September but was deemed not heavy enough due to the weight she lost from the jab.

Nikki said she is at increased risk of pancreatitis and is struggling to eat ‘fatty’ foods without being poorly.

Despite the jabs giving her confidence and improving her mental health thanks to her dramatic weight loss, she is now off Mounjaro.

The single mother admits the negatives now outweigh the positives, so is urging others to ‘do their research on the potential side effects’.

Nikki said: ‘I can’t eat anything fatty, I had a chippy tea and it made me so poorly.

‘I came off Mounjaro after the surgery because I was seven stone down. Now the cons outweigh the pros.

‘Now I am at increased risk of pancreatitis. I was supposed to be having a gastric sleeve in September but I won’t anymore. I’m not heavy enough to get it done.

‘It absolutely changed my life, people speak to me now that would have never spoken to me before, even to the point where people add me on Facebook that wouldn’t have added me before.

‘Do your research, you have to be ready and have the determination. 

‘I did my research and I knew all the side effects but I see so many women who have not done research.

‘All the Mounjaro pages on social media show everyone is doing it but no one is looking into the side effects.

‘It’s given me confidence, I’m not as fatigued anymore. It improved my mental health massively.’

A spokesperson for Lilly, who manufacture Mounjaro, said: ‘Patient safety is Lilly’s top priority, and we take any reports regarding patient safety seriously.

‘Regulatory agencies conduct extensive independent assessments of the benefits and risks of every new medicine and Lilly is committed to continually monitoring, evaluating, and reporting safety data to ensure the latest information is available for regulators and prescribers.

‘We encourage patients to consult their doctor or other healthcare professional regarding any possible side effects they may be experiencing and to ensure that they are getting genuine Lilly medicine.’