Mounjaro trial begins in Manchester
A five-year trial assessing the impact of the weight-loss injection Mounjaro has begun in Greater Manchester, with the first group of participants now enrolled through local GP practices.
The study will evaluate the health benefits of tirzepatide in everyday clinical settings. Up to 3,000 adults are expected to take part, making it the first large-scale real-world evaluation of its kind in the UK. The initiative forms part of a £279m partnership between manufacturer Eli Lilly and the UK government aimed at tackling major public health challenges, including obesity.
Professor Martin Rutter, professor of cardiometabolic medicine at the University of Manchester and chief investigator for the trial, said the research would explore how effective early intervention could be in helping people manage obesity.
Tirzepatide is a once-weekly injectable medication that suppresses appetite by mimicking hormones that help regulate hunger and satiety. Previous clinical trials have shown average weight loss of up to 20 per cent after 72 weeks of treatment with Mounjaro.
The Greater Manchester trial will track outcomes beyond weight loss alone — including quality of life, employment status and the number of sick days taken — offering a broader picture of how treating obesity can improve long-term wellbeing and economic participation. The research will be delivered through primary care, with GPs issuing and monitoring treatment.
The scale of the challenge is significant. Around 600,000 adults in Greater Manchester are living with obesity, according to NHS Greater Manchester Integrated Care Board chief executive Mark Fisher. A 2023 report by Health Innovation Manchester estimated the regional cost of obesity at more than £3bn a year when factoring in NHS treatment, social care and the impact on quality of life.
Nationally, illnesses related to obesity cost the NHS around £11bn annually, according to Health Secretary Wes Streeting.
The trial’s outcomes are expected to inform future obesity management strategies and the potential role of advanced pharmacotherapy in routine NHS care.