A cultural obsession met a miracle drug met a monopoly price: the bill landed in a health service that had no plan to pay it. A tongue-in-cheek autopsy of the most expensive medicine in NHS history.
It is easier to be furious at a person than at a spreadsheet. So when the health service quietly logged its largest annual drug bill in 2025, the national imagination did not reach for “structural underinvestment compounded by monopoly pricing.” It reached for a red carpet. Somewhere between a Met Gala silhouette and a nation of before-and-after photos, thinness stopped being an aesthetic and became a prescription: and it feels satisfying to blame the most photographed woman on Earth for the consequences.
It is, of course, nonsense. A reality star from Calabasas did not personally hollow out a Barnsley A&E. But she makes a convenient face for a phenomenon that is entirely real: a class of drugs so effective, so desired, and so expensive that it has quietly rearranged the arithmetic of British healthcare. The interesting story isn’t the celebrity. It’s what the drugs actually buy, and for how long.
The biggest bill in the building
Mounjaro alone reached roughly £574 million in England across the 2025/26 financial year, making it the single most expensive medicine in NHS history: a title previously held by drugs that treat cancers and rare diseases, not clothing sizes. The manufacturer raised the price by as much as 170% for a month’s supply in September 2025, because a monopoly supplier of the thing everyone wants can do exactly that.
And a pound spent is a pound spent. Every million diverted into appetite hormones is a million not staffing a rota, not shortening a referral queue, not oiling the machinery of an emergency department already treating its four-hour target as folklore. The dominoes are real: thinner staffing, longer waits, an over-reliance on the cheaper end of the workforce to hold a rota together. But dominoes are a distraction. The real question is the one that never makes the headline.
What does £574 million actually buy?
Here is the uncomfortable part, and it’s the part the cheerleaders skate over: the benefit reverses when the drug stops.
This is not a hunch. In the landmark STEP 1 extension, people regained around two-thirds of their lost weight within a year of coming off semaglutide, ending up roughly 5.6% below their starting weight rather than the 17% they’d achieved; the improvements in blood pressure, cholesterol and blood sugar drifted back toward baseline right alongside the pounds. A tirzepatide study in JAMA Internal Medicine found that by week 88, 82.5% of people had regained at least a quarter of the weight they’d lost, with the cardiometabolic gains unwinding in proportion. Oxford researchers put it more bluntly still: patients who lost around 15kg regained close to 10kg in the first year off the drug, at a brisk 0.8kg a month.
In fairness, the real world is a little kinder than the trials. In one dataset of nearly 190,000 patients, more than half had held onto their loss two years after stopping, with total regain in only about a fifth: probably because real patients taper gradually and keep some of the diet-and-exercise scaffolding, rather than being yanked onto a placebo overnight the way trial subjects are.
But look closely, because that reassurance is a trap. The only dependable way to keep the benefit is to keep taking the drug. Which means the £574 million is not a one-off investment that quietly pays for itself in a decade of prevented heart attacks. It is the first instalment of a permanent, compounding subscription. These medicines behave far less like a cure and far more like a statin or a blood-pressure pill: effective precisely as long as you keep paying, for the rest of your life, for an ever-growing population. The NHS has itself planned a rollout stretching over roughly twelve years: an admission, in bureaucratic disguise, that this is not a treatment that ends. It is a fixture.
So the honest answer to “how much of that half-billion becomes lasting health?” is: only the portion belonging to people who never stop. And that portion is not cheaper next year. It is the same eye-watering price, again, plus everyone new who joins the queue.
The case for the drug (which is real, and inconvenient)
None of this makes the drugs a boondoggle. Obesity already costs the NHS somewhere north of £11 billion a year in the diabetes, joint replacements and cardiac events it drags behind it. If keeping millions of people on effective medication genuinely prevents a meaningful slice of that, the maths can work: the same way it works for any chronic-disease drug taken indefinitely.
But that framing is the whole game, and almost nobody says it out loud. The debate is conducted as though this is a heroic one-time intervention, when the economics are those of a lifelong maintenance therapy purchased at monopoly rates. Those are extremely different things to budget for. One is a lump sum. The other is a standing order with no end date and a supplier who has already shown he’ll put the price up.
The two grown-up moves
If this is a subscription rather than a cure, then the per-dose price is not a detail. It is the entire ballgame: the health service will be buying this dose forever.
Negotiate like the biggest customer in the world, because it is one. A national system covering tens of millions is not a supplicant. Outcome-based deals where the taxpayer pays more only when the weight actually stays off; volume commitments; capped budgets: dull instruments, precisely suited to a bill that recurs annually until the end of time.
And let the patent cliff do the heavy lifting. Statins cost pennies today for exactly one reason: competition arrived. Semaglutide is expected to lose exclusivity in the UK around 2028, with generics already surfacing in other markets, and tirzepatide follows around 2032. Nobody sane tells a seriously ill patient to “wait until 2028.” But a system with any strategic patience would prioritise the highest-need patients now and build every budget on the assumption that today’s price is a temporary insult, because it is. Paying a monopoly premium, in perpetuity, for a drug whose cheap generic future is already visible on the calendar, is the most expensive possible way to do a sensible thing.
The verdict
Kim Kardashian did not bankrupt the NHS. A very old obsession with being thin collided with a genuinely brilliant, genuinely extortionate class of medicine, in a system with no coherent plan to pay for a benefit that evaporates the moment the injections stop. The drugs may well be worth it. But they are worth it as a lifelong commitment bought at a fair price: not as a half-billion-pound one-night stand that has to be repeated, at full cost, every single year.
The celebrity was never the problem. She just, as ever, had the better lighting.