Weight loss success turned to surgery nightmare: baker's gallbladder warning for seniors considering Mounjaro

When Julie Reilly decided to try Mounjaro weight loss injections, she was hoping to silence the constant temptation of working surrounded by wedding cakes and pastries all day.

What she didn't expect was to end up 'rolling on the floor' in agony, needing emergency gallbladder surgery after just one year on the medication.

The 57-year-old professional baker from Birmingham lost an impressive four stone during her year on the weight loss injections, but her success story took a painful turn that she believes could have been prevented with clearer warnings about the medication's risks.

When weight loss success comes at a cost

At 5ft 1in and weighing 76.2kg when she started, Julie had a BMI of nearly 32, placing her in the medically defined 'obese' category. In the UK, gallstones affect 10-15 per cent of adults, making this a common consideration when prescribing weight loss medications, but Julie says she was never asked about existing gallbladder issues before starting her injections.

'I'm only small, so being a 12-stone woman was a lot,' Julie explained. However, looking back after her ordeal, she says she never would have taken the medication if she'd understood the real risks.

The connection between Julie's gallbladder problems and her weight loss medication isn't coincidental. For gallbladder or biliary disease, the composite of gallbladder or biliary disease was significantly associated with tirzepatide compared with placebo or basal insulin (RR 1.97, [95 per cent CI] 1.14 to 3.42), meaning users face nearly double the risk compared to those not taking the medication.

The hidden gallbladder risks nobody talks about

While Mounjaro's information leaflet does warn that gallstones are a 'common' side effect affecting 'up to one in 10 people', clinical trials show that gallbladder-related adverse events occur in approximately 0.6 per cent of people taking Mounjaro, with most cases being mild to moderate. However, the timing of these complications follows a concerning pattern.

Based on observed trends in SURMOUNT trials, risk appears to vary over time: Weeks 1-8: Initial risk period as body adapts to medication and calorie reduction begins. Weeks 8-20: Period of potentially higher risk—many gallbladder events in trials were observed during this timeframe.

For Julie, the timeline matches perfectly. She started experiencing increasing stomach pains after beginning Mounjaro in August 2024, with the worst symptoms hitting during the critical weeks identified in clinical trials.

Why rapid weight loss triggers gallstones

The mechanism behind weight loss medication gallbladder problems is well understood by researchers. Enhanced weight loss: While beneficial overall, the significant weight loss (20-25 per cent in trials) can trigger gallstone formation if too rapid. Changes in bile composition: Weight loss alters cholesterol metabolism, potentially increasing bile lithogenicity.

Rapid weight loss—a known risk factor for gallstone formation—requires careful management to minimise complications. The key to safe treatment is losing weight at a moderate pace (0.5-1kg / 1-2lbs per week) and monitoring for warning signs.

For seniors particularly, this presents additional considerations. Women are twice as likely as men to develop gallstones, with prevalence increasing with age. Julie's case represents a perfect storm—she was a woman over 50 going through menopause, losing weight rapidly, and had pre-existing stomach issues that were initially dismissed as menopausal symptoms.

The menopause connection doctors missed

Julie's experience highlights a concerning pattern many women over 50 will recognise. Before starting Mounjaro, she had been experiencing stomach pains for 18 months, but her GP attributed them to menopause symptoms.

'Everything that you get gets blamed on menopause symptoms. That's what they told me at first when I started getting these pains in my stomach,' Julie said.

This dismissal potentially masked early gallbladder issues that could have been identified before starting a medication known to increase gallbladder complications. Most people with gallstones (80 per cent) never experience symptoms; these are called 'silent' or asymptomatic gallstones, but Julie's pre-existing symptoms suggest her gallstones weren't entirely silent.

The recovery challenge for working seniors

Julie's recovery story reveals another issue many seniors face—the pressure to return to work too quickly after surgery. As a wedding cake maker during peak season, she felt she couldn't afford time off for proper recovery.

'I only had a week off, I wasn't well, I don't know how I went back to work but I didn't want to let anybody down. I don't even know how I stood doing it. I was in agony,' she recalled.

In clinical trials, about 1 in 200 people on Mounjaro got acute gallbladder disease. That refers to gallstones or inflammation of the gallbladder (usually caused by gallstones). For those who do develop complications requiring surgery, recovery can be challenging, particularly for older adults who may heal more slowly.

The manufacturer responds

Eli Lilly, the company behind Mounjaro, maintains that patient safety is their priority. A spokesperson for Lilly, who manufacture Mounjaro, 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 gallstones is a common side effect when used for weight management, and an uncommon side effect when used for type 2 diabetes.'

However, Julie's experience suggests the warnings may not be clear enough. 'They don't actually say that, no one tells you that it could cause gallstones. They don't ask if you have any gallbladder issues before you take the jab,' she said.

The ongoing dilemma

Perhaps most telling is Julie's admission that despite her ordeal, she's continuing with her final weeks of Mounjaro treatment. 'I have four weeks left on this last one and then I'm coming off. People say I don't even look like the same person,' she said.

This highlights the complex relationship many people have with these medications—the dramatic results can feel worth the risks, even after experiencing serious complications.

What this means for Australian seniors

While Julie's story comes from the UK, it holds important lessons for Australian seniors considering weight loss medications. The physiological risks remain the same regardless of geography, and older Australians—particularly women going through or past menopause—face similar risk profiles.

Before considering any weight loss medication, experts recommend a thorough discussion with your GP about your individual risk factors, including any history of digestive issues that might have been previously dismissed or attributed to other causes.

If you have symptoms of gallbladder problems, stop taking Mounjaro and seek medical advice immediately. Symptoms may include severe upper abdominal pain, fever, yellowing of the skin or eyes (jaundice), and pale stools.

The bigger picture on medication risks

Julie's experience isn't isolated. A small number of people taking Mounjaro have reported mood changes, including depression, anxiety, and suicidal thoughts. A 2024 study in the International Journal of Clinical Pharmacy looked at 31,444 reports of these side effects in people taking GLP-1 drugs Mounjaro/Zepbound, Victoza/Saxenda (liraglutide), or Ozempic/Wegovy (semaglutide). Just 2 per cent of the reports came from Mounjaro users.

While this suggests Mounjaro may have a lower risk profile for psychiatric side effects compared to other similar medications, it reinforces the importance of comprehensive risk assessment before starting any weight loss medication.

Whether you've had a similar experience with weight loss medications or have questions about the risks and benefits, we'd love to hear your thoughts and experiences in the comments below.