Shaping the UK’s long term relationship with tirzepatide

Tirzepatide (Mounjaro) has had a remarkable journey to prominence since its UK marketing authorisation in 2023.1 Approved for glycaemic control in type 2 diabetes and weight management in people who are overweight or obese, it has been described as a “miracle drug”2 and was even angled to help the economy by getting unemployed people back to work.3

The National Institute for Health and Care Excellence (NICE) approved funding of tirzepatide for weight management in December 2024.4 It has approved other weight loss injections for patients without diabetes but treatment was typically limited to two years under a specialist weight management clinic. However, NICE recommends that tirzepatide be initiated and managed in primary care with an indefinite treatment period, which has important implications for the NHS.

Several clinical uncertainties about treatment with tirzepatide remain. Long term treatment exposes patients to longer term side effects, but the longest trial of tirzepatide (Surpass-4) lasted 102 weeks, and additional evidence on side effects may not come …