A woman who believed she could not lose weight on Mounjaro because she was 'lazy' discovered she had a 12kg cancerous tumour growing inside her. Becki Ward, 33, from Great Yarmouth, Norfolk, started taking the weight loss injections in October 2024 after struggling to lose weight naturally, but was puzzled when they did not seem to work.
After experiencing stomach pains and night sweats, she visited her GP. Following five months of tests, she was diagnosed with pseudomyxoma peritonei, an exceptionally rare form of mucinous cancer. Her abdomen swelled so dramatically that she appeared to be 'having twins'.
In August 2025, she underwent surgery to remove the 12kg tumour, along with several organs, and had a total hysterectomy, which placed her into premature menopause. The operation lasted 11 hours, longer than expected, as the cancer had spread further than doctors initially thought.
Ms Ward said: 'I've always struggled with my weight, so I decided to start taking Mounjaro in October 2024. At first it was working well, but then I realised I wasn't losing weight as fast as everybody else. I assumed it wasn't working because I was lazy or overeating.'
She added: 'I was so shocked when I got the diagnosis. The thing I've always been most terrified of is getting cancer. I just wasn't expecting it.' Doctors believe she may have been living with the cancer for five years without knowing.
