The box of aspirin on the pharmacy shelf costs, in normal times, 38p. In recent months, some wholesalers have been charging nearly eight pounds. That single data point, trivial-sounding, almost absurd, captures something the NHS's annual planning cycles, procurement frameworks, and resilience strategies have consistently failed to reckon with: the health service runs on oil.

Not metaphorically. In one way or another, almost all medications rely on petroleum. Common pharmaceutical inputs, from solvents and reagents to inactive ingredients, originate from petrochemical processes. The plastic of the IV bag, the blister pack, the surgical glove, the syringe, all are downstream of the same industrial chain that threads through the Strait of Hormuz. When the US and Israel struck Iran in late February and Tehran closed the strait in response, the disruption to global energy markets was immediate and widely reported. The disruption to NHS medicine supplies was slower, more complex, and in many respects more consequential.

Off-patent medicines account for 85 per cent of NHS prescriptions and run on high efficiency and razor-thin margins. Any prolonged crisis that drives up operating costs will disproportionately affect their manufacturers and risks leading to supply shortages or increased costs for the NHS. The crisis has done exactly that. Prices of certain over-the-counter medicines have increased by up to 30 per cent since February, driven by higher manufacturing and transport costs. Air freight costs have doubled. One in five NHS medicines is transported by air, and with Middle Eastern air routes severely disrupted, capacity has fallen sharply.

The government's public response has been notably measured. The Minister for Health Innovation and Safety said in April that the UK's exposure to the Middle East for medical products is limited, pointing to well-established contingency arrangements. That framing may be defensible at the level of acute supply triage, but it sidesteps the structural question the crisis has made unavoidable. In late March, Sir Jim Mackey, the chief executive of NHS England, issued a warning that some medical supplies would run out in a matter of days. He pointed out that the NHS cannot just store vast quantities permanently since many medicines are perishable and preservation is costly. The contingency arrangements, in other words, have limits, and those limits are being tested in real time.

What makes the current moment particularly uncomfortable for NHS planners is that this is not a bolt from the blue. The fragility of generic medicine supply chains was exposed during Covid-19. The Red Sea Houthi disruptions in 2024 raised the same questions about routing and resilience. Each time, the immediate pressure was managed, conclusions were drawn, and the underlying vulnerability remained. The emerging lesson from the Strait of Hormuz is that innovations in supply chain resilience may be just as critical as scientific innovation to ensuring that medicines can continue to reach patients. The NHS has not yet acted as though it believes this.

The partial reopening now under way, backed by the UN and contested by Iran, does not resolve that. Some Global North countries, including the NHS in the UK, have been sounding the alarm bells and warning of shortages in the weeks ahead. Even if shipping normalises relatively quickly, the cost pressures already embedded in manufacturing and logistics will not unwind at the same pace. Others cite long-term concerns about the war's impact on supply chains, expressing doubt that traffic in the strait will return to pre-war levels. The political resolution, whatever form it takes, will not immediately restore the economics of cheap generic medicine production that the NHS has spent decades relying upon.

There is a wider question here about what kind of risk the British state is willing to accept in health procurement. The drive for efficiency, commendable in isolation, has produced a system of just-in-time supply at the precise moment when geopolitical instability makes just-in-time a liability. The NHS is not alone in this; the entire Western pharmaceutical model has optimised for cost over resilience. But the NHS, given its scale and its public character, is the institution that will be asked to answer for the consequences when the shelves are bare.

A ceasefire in the Gulf creates breathing room. It does not create a domestic API manufacturing base, diversify supplier geography, or fund the kind of strategic stockpiling that would provide real insulation against the next disruption. NHS sources predict shortages from June 2026 regardless of how the political situation resolves. The waterway may reopen. The problem it has revealed will not close with it.