A mother-of-three who dropped three sizes and more than three stone on weight loss drug Mounjaro said ‘it wasn’t worth it’—after the jabs triggered significant hair loss.
Kathleen Smith, 40, was tipping the scales at 12-and-a-half stone when she decided to try the slimming drug.
She bought Mounjaro privately and lost 10lbs within two weeks but immediately starting noticing unpleasant and distressing side effects.
Ms Smith, from Telford, Shropshire, thought she just had to ‘ride it out’ and kept using the jab for a further five months.
She began suffering dizzy spells, suffered from embarrassing ‘foul burps’ and noticed she was losing clumps of her thick blonde hair—and it’s still falling out.
She said: ‘At first noticed it was coming out when I brushed it, and when I went showered, the sinkhole was getting blocked with hair.
‘I have always had really thick hair but now, every time I put my hands through my hair it feels like I have got an undercut.’
She added: ‘I wouldn’t recommend [the treatment]. It’s not worth it—we don’t know what damage we’re doing to our organs.’
Kathleen Smith, 40, dropped three sizes on Mounjaro but says it wasn’t ‘worth it’ after she lost her hair and it left her feeling like she has an undercut
Ms Smith before (81 kilos) and after (59.9 kilos) her Mounjaro weight loss injections, where she lost 19 kilograms in five months
After taking the fat jab for three months she started getting dizzy, would have severely foul burps and noticed she was losing clumps of her thick hair
Ms Smith claimed her ‘disgusting’ sulphurous burps became so bad that her boyfriend, 50, would have to leave the house.
‘The stench was grotesque,’ she recalls. ‘My boyfriend was heaving. It was so embarrassing.
‘I had to go outside if I wanted to burp.’
Ms Smith consulted her GP who said her folic acid and iron levels were low and suggested she stop the jabs in February.
Despite this, two months on, she is still suffering from dizzy spells and hair loss.
Drug firm Eli Lilly, who make Mounjaro, list diarrhoea, indigestion and decreased appetite as possible side effects of the jab.
Ms Smith had previously tried different diets to lose weight but would get ‘comfortable’ and couldn’t keep the weight off.
As a busy full-time carer to her eldest child, she would often snack throughout the day—going through six bags of crisps and always had a chocolate bar with her cup of tea.
She noticed her hair was coming out in the brush and says she always had really thick hair
She decided to give Mounjaro a go to help reduce her appetite and tackle her high cholesterol, which put her at increased risk of a heart attack or stroke.
The 40-year-old started taking the jab in September 2024 but experienced the side effects within two days.
She said: ‘Within two days there was liquid coming out my bottom end. I’d go to the loo eight to nine times a day.’
Ms Smith added: ‘I had really bad heartburn, and no hunger whatsoever.’
But she had seen others talking about their experiences on TikTok and felt encouraged to ‘ride it out’.
She was also motivated by her weight loss and her Fitbit stats. She said: ‘I was seeing the numbers on Fitbit.
‘I’m a visual person so I was seeing all the red and yellow [indicating her health statistics such as weight, body mass index, resting heart rate were in unhealthy ranges] and wanted to get into the green—despite all the side effects.’
Ms Smith started getting dizzy spells and blackouts in December 2024, three months after starting in September.
She said: ‘If I was squatting down when I would stand up all the blood rushed from my head to my legs and a black cloud would go over my eyes.
‘My head would drop and I would have to sit down and wait for it to pass. It would happen three to four times a day.’
She decided to come off Mounjaro—despite the facts she’d slimmed down to a healthy size 10, weight just over nine stone at her lowest.
Ms Smith calculates that she spent £860 on the jab in five months. But she said: ‘My friends and family just kept commenting that I looked really ill.’
Since stopping, alongside continuing hair loss, she claims she cannot complete simple tasks like the washing because of the dizziness.
Her old habits have come back and she’s found herself snacking again. She has put on just over a stone since being off Mounjaro and now weighs 10-and-a-half stone.
Despite this, Ms Smith said: ‘I wouldn’t go back on it.’
Commenting on the case, Eli Lilly said: ‘Patient safety is Lilly’s top priority.
‘We take any reports regarding patient safety extremely seriously and actively monitor, evaluate, and report safety information for all our medicines.
‘The Mounjaro (tirzepatide) patient Information leaflet warns that various gastrointestinal side effects, including diarrhoea, burping and decreased appetite, as well as heartburn, hair loss and dizziness are common or very common side effects.
‘We encourage patients to consult their doctor or other healthcare professional regarding any side effects they may be experiencing and to ensure that they are getting genuine Lilly medicine.’
