GLP-1 drugs on the NHS: Can, and should, we roll them out at scale?

GLP-1 medications such as semaglutide and tirzepatide have been called a ‘breakthrough’ in tackling obesity. With clinical trials showing double-digit weight loss in just months, and approval for NHS obesity treatment secured in late 2023, expectations are sky high. But here’s the catch: with 64% of adults overweight or obese in 2022, weight-loss medication demand is rising fast, and the system meant to deliver them isn’t keeping pace.

A prescribing boom, but for whom?

GLP-1 (Glucagon-like peptide-1) drugs weren’t designed for weight loss, they were first licensed to treat type 2 diabetes. But after clinical trials (such as STEP and SURMOUNT) showed 15%–17% weight loss with lifestyle support, the case for broader use became hard to ignore, and by October 2023 semaglutide and tirzepatide had been approved for weight loss by NICE (the national health technology assessment body of England).

GLP-1 prescribing has taken off, even though the NHS hasn’t yet fully rolled out NICE’s obesity guidance, and national diabetes rates have barely changed in this time frame. So what’s driving the surge?

Current trends suggest, partly, growing off-label use for weight loss, driven by media attention, private demand and public appetite. In fact, while fewer than 200,000 patients are thought to access GLP-1s through the NHS, over 1.4 million may be using them privately – raising concerns about equitable access.

An NHS bottleneck

Let’s say you’re eligible for GLP-1s through the NHS – can you get them? That depends on where you live. Provision of Tier 3 weight management services, a specialist programme for overweight individuals, varies widely across England. Some integrated care boards (ICBs) have robust digital referral systems while others were until recently still faxing forms. Crucially, there’s no statutory requirement for ICBs to offer these services at all, with 1 in 6 ICBs having stopped accepting new referrals to specialist Tier 3 services due to capacity limits, and some regions closing lists entirely.

Weight-management services

• Tier 1: Universal prevention (population health)

• Tier 2: Community lifestyle services (often council run)

• Tier 3: Specialist multi-disciplinary weight management (NHS-commissioned; dietitians, psychological support, weight-loss medications)

• Tier 4: Bariatric surgery

It gets worse. The NHS Digital Weight Management Programme, a 12-week online service to help people lose weight, isn’t fully integrated into GP systems. In theory, patients starting drugs such as semaglutide or tirzepatide should be referred to these lifestyle services to maximise results and prevent weight regain when treatment stops. But without full integration into GP systems, these referrals can be slow and patchy, meaning patients may miss out on crucial lifestyle support, resulting in a reliance on costly GLP-1s without the behavioural interventions needed for long-term success.

Funding gaps

Like most NHS services, this isn’t just an infrastructure problem. It’s a funding one.

NHS modelling shows that even in the first year, if all eligible people came forward and 7 in 10 started tirzepatide, the cost could reach £3.1 billion (including the drug itself, specialist weight-loss clinics, extra dietitian and nursing staff, and digital support systems). For scale, the NHS primary care medicines budget in 2022/23 was around £9.5 billion. In this context, a £3.1 billion cost figure would account for roughly one-third of that spending – a significant and unprecedented portion.

Beyond the hype: some uncomfortable questions

Although GLP-1 medications can be promising pharmacological tools for weight management, their increasing prominence raises several important ethical and public health concerns. Modelling obesity as a condition best addressed through pharmacological intervention rather than by tackling the social, environmental and structural determinants, such as food insecurity and urban design, contributes to the risk of medicalising obesity. This shift in focus may inadvertently divert attention and funding away from upstream public health interventions, including investment in healthy food access and community-based prevention programmes.

Then there’s the long-term sustainability: clinical evidence shows that patients often regain weight after discontinuing GLP-1s, raising concerns about lifelong dependency on high-cost medications without adequate lifestyle or behavioural support.

Finally, there’s commercial pressure. With celebrity endorsements and aggressive marketing, are we at risk of NHS prescribing being shaped more by hype than health equity?

GLP-1s offer real promise – but only if the NHS can deliver them wisely.

Right now, we have a fragmented system, rising demand, and no guaranteed national funding. We risk creating a postcode lottery, or worse, a two-tier system where those who need treatment most are the least likely to access it. This isn’t a new dilemma for the NHS – past debates over IVF show how high-demand treatments can transform lives but also strain budgets, crowd out prevention, and deepen regional inequalities if rollout isn’t carefully planned.

So, as the rollout gathers pace we should ask: can the NHS turn the weight-loss promise of GLP-1s into a public health success, or will it be another medical breakthrough that outpaces the system designed to deliver it?