Wider access to weight-loss injections on the NHS could deliver significant economic gains by reducing sick days and alleviating the burden of obesity-related illnesses, according to new research. A study involving 421 NHS patients using the latest generation of obesity drugs found that the number of sick days taken fell by a third within three months of starting treatment. Combined sick leave decreased from 517 days in the three months prior to starting the injections to 334 days after three months of use, based on data from Oviva, the UK’s largest provider of weight-loss support services.
After six months, 77% of patients reported taking no sick leave at all, an increase from 63% before beginning treatment. These findings underscore the potential economic impact of more widely rolling out obesity injections. Government figures indicate that UK workers took 149 million sick days in 2024, a reduction from the pandemic-era peak but nearly 10 million more than pre-2020 levels.
Health Secretary Wes Streeting has previously identified obesity as a significant impediment to the workforce, noting that individuals living with obesity take, on average, an additional four sick days per year, with many leaving employment entirely. Mr Streeting has argued that these drugs could play a pivotal role in reducing economic inactivity by addressing obesity and facilitating the return of unemployed Britons to work.
Government modelling suggests that a widespread rollout could save taxpayers £5 billion annually through productivity gains and reduced healthcare costs. Obesity is estimated to cost the UK economy approximately £98 billion each year, including £15 billion in lost productivity and £19 billion in direct NHS spending.
Despite political enthusiasm, the rollout of injections such as Mounjaro, produced by Eli Lilly, has been sluggish. By the end of June, 32,000 patients were still waiting for an NHS weight management appointment, while only 1% of eligible patients currently receive treatment, according to Oviva. It is anticipated that a quarter of a million people across England will be prescribed Mounjaro on the NHS over the next three years, yet demand is already surpassing supply.
Mounjaro itself is also facing its own difficulties after Eli Lilly announced a sharp price increase, attributed to pressure from former US President Donald Trump, that led the average price to increase by 126% per jab, with some doses rising by as much as 170%.
In response, approximately 625,000 patients are expected to transition to NovoNordisk’s Wegovy, also known as Ozempic.
In the initial 24 hours post-announcement, Ozempic sales rose by 400%, as reported by weight loss jab provider CheqUp, escalating to a 600% increase within 48 hours as patients sought to avoid the impending price rise effective from 1 September.
Toby Nicol, CEO of CheqUp, stated, “As news of the Mounjaro price rise spreads, weight loss jab patients are voting with their wallets and making the switch to Wegovy, which is nearly as effective but has a considerably lower cost.”
Nicol further suggested that Wegovy might become the UK’s most popular weight loss treatment as patients transition from Mounjaro. CheqUp reports that up to 80% of Mounjaro users have indicated they will switch or discontinue the drug due to the price increase. Eli Lilly attributed the price adjustment to addressing pricing inconsistencies with other developed countries, including Europe, following complaints from Trump’s administration about “foreign freeloaders” relying on the US to pay more for medicines.
Pumping productivity —
The market for weight-loss drugs is projected to reach approximately $50 billion (£36 billion) by the end of 2024, with expectations to double by the decade’s end, according to Morgan Stanley.
Martin Fidock, UK chief of Oviva, has urged ministers to expedite distribution: “The Chancellor talks about firing up Britain’s productivity but doesn’t address the millions who are locked out of work by poor health. People living with obesity are twice as likely to be off sick, yet Britain’s postcode lottery for healthcare means just a fraction of patients get access to treatment.”
The average patient in Oviva’s study was 49 years old, an age group where obesity typically peaks and comorbidities such as anxiety, depression, and hypertension are common. In addition to the reduction in sick days, many patients reported lifestyle changes, including increased water consumption and more regular vegetable intake.
Research has also associated the new generation of weight-loss treatments with broader health benefits, such as halving the risk of death from cardiovascular disease and reducing cancer risks. Earlier this year, the Tony Blair Institute suggested that weight-loss injections could be offered to half of all UK adults as part of a national obesity strategy. However, if all 26 million Britons with a BMI of 27 or above were prescribed the drugs, the annual cost would be approximately £38 billion, around 17% of total NHS spending.
The current debate facing policymakers is whether the productivity gains and reduced healthcare costs justify the upfront expense of scaling up access.
