A global shortage of ibuprofen has hit the UK, with supplies of the drug affected in major high street supermarkets like Tesco and Sainsbury's.
On social media, supermarket customers have been complaining that shelves are empty of the painkillers.
One photo of a Sainsbury's sign showed a notice blaming a "supply issue" for the problem.
The notice said: "We are currently experiencing supply issues across Sainsbury's Ibuprofen caplets and tablets.
"We are working hard with our suppliers to resolve this as soon as possible. We apologise for any inconvenience caused."
Tesco has claimed the issue is due to a "global shortage" of the drug, The Sun reported.
The supermarket's own-brand and other products are affected, Tesco said.
Customers have been turning to paracetamol instead, leading to a run on that medication as well.
One said: “Over the past couple of weeks I have tried to buy in Boots, Superdrug and Tesco without success. The shelves are either empty or filled up with expensive brand alternatives.”
Some have claimed people are stockpiling the drug with Brexit looming.
Disappointed customer Scott Reid complained: "No generic ibuprofen in local Tesco or Aldi for three weeks now and no date as to when supplies will resume. Normally thousands of packs. Clearly somebody somewhere is stockpiling..."
A spokesman for Sainsbury's told MirrorOnline: “Some stores are running low on some own brand ibuprofen and paracetamol lines. We’re working to replenish as quickly as possible and are sorry for any inconvenience this may cause.”
It comes after the British Medical Association, over shortages of a host of common medicines, caused by manufacturing problems.
