HSE faces €3B cost as obesity drug Mounjaro debated

A €3 Billion Prescription for Obesity

The Irish health service faces a potential expenditure of up to €3 billion to subsidize the weight-loss drug Mounjaro. With over one million people potentially eligible for the treatment, the proposal has ignited a fierce debate over whether the state should prioritize pharmaceutical intervention or aggressive regulation of the food industry.

Consultant endocrinologist Prof Donal O’Shea describes the move as “transformative” for managing obesity and associated conditions like type 2 diabetes and hypertension. He argues that while the upfront cost is high, it would be “massively well spent” by preventing future health crises, such as the need for hip replacements or the development of chronic diabetes.

The Path to Cost-Effectiveness

Negotiations with manufacturer Eli Lilly have yielded “significant” price reductions, according to Professor Michael Barry of the National Centre for Pharmacoeconomics. As a result, the drug is considered close to being cost-effective. However, the HSE Drugs Group has not yet finalized a recommendation. A spokeswoman noted that several meetings remain necessary before the matter reaches HSE management for a final decision.

Under the proposed framework, Prof O’Shea suggests that eligibility should target individuals with a BMI over 30, or those with a BMI of 27 who also present with comorbidities such as cardiovascular disease or pre-diabetes.

Global Threats and Commercial Interference

The policy discussion arrives alongside the publication of The Lancet Commission on 21st Century Global Threats to Health, which identified obesity as the leading preventable health loss in 154 of 204 countries. The report estimates that obesity puts 23 billion years of healthy life at risk between now and 2100.

Kent Buse, co-chair of the World Obesity Federation’s Policy and Obesity Prevention Committee, noted that the commission’s modeling found that even if obesity medications reached half of all eligible patients, the impact on population-level health trends would be small. The report argues that the primary leverage for change lies in modifying food, transport, and physical activity environments. Prof Buse further suggested that commercial influence remains the primary barrier to progress, stating that health policies must be insulated from such interference.

Legislating Against Unhealthy Consumption

Evidence from abroad suggests that legislative intervention can reduce the consumption of unhealthy products. In Chile, laws restricting the marketing of sugary drinks to children and banning their sale in schools contributed to a 23.7% reduction in purchases of these beverages. Similarly, a tax on ultra-processed foods in Colombia led to a 4.3% drop in national consumption within one year, according to a 2025 paper in BMC Medicine.

Ireland’s own 2018 tax on sugar-sweetened drinks resulted in a 30.2% decrease in consumption from retail outlets and a 19.8% reduction in food service venues. Per capita sugar consumption from these sources fell from 5kg at the time of the tax to 3.8kg by 2022. Dr. Catherine Conlon, writing in The Irish Times, emphasized that these policies—along with front-of-pack labeling and healthy school food programs—have proven effective elsewhere, yet no political party has adopted similar systemic regulations to complement the proposed drug rollout. Following the 2024 evaluation of the sugar tax, The Irish Heart Foundation formally requested that the government extend the levy to all high-sugar foods.

Clinical and Structural Perspectives

Prof O’Shea maintains that eligibility would be limited to those with a BMI of 30 or higher, or individuals with a BMI of 27 who suffer from specific comorbidities like hypertension, cardiovascular disease, or type 2 diabetes. Yet, experts argue that structural changes to food environments are necessary to address the root causes of the epidemic, noting that even with 50% of eligible people receiving GLP-1 agonists like Mounjaro, the projected global increase in obesity rates would only see a small reduction. There is a clear precedent for such action: the 2018 sugar tax drove four out of five leading soft drink brands to reformulate their products to lower sugar content below tax thresholds.

More on Mounjaro: MPs Warn NHS Mounjaro Rollout is Too Slow, Creating 'Two-Tier System