Hand sanitiser sales are being limited at pharmacy chains as fears over the coronavirus have boosted demand.
Boots and LloydsPharmacy both said they are restricting the products - which can help to prevent the spread of the virus when hand-washing is not possible - to two per person.
The decision comes as some hand sanitisers are being sold online at inflated prices.
Pharmacies said they are working to increase the supply of the products.
The NHS says that washing your hands is a key part of preventing the spread of viruses, but hand sanitiser gel can be used when soap and water are not available.
As the UK warns that widespread infection is "highly likely", chemist chains said they had to ration the products, with market research data from Kantar Worldpanel showing sales more than tripled in February.
Meanwhile, one pharmacy in Coventry told BBC News they have struggled to restock hand sanitisers amid increased demand for the product - including from local businesses such as taxi companies and hairdressers.
Ali Shiraz, of Hillfields Pharmacy, said: "We can't get any hand sanitisers at all. The demand has been really, really high.
"We're looking at maybe 50 to 60 people a day have been asking for particular hand sanitisers."
A spokesman for LloydsPharmacy, which has 1,500 branches across the UK, said: "We know that having access to products like hand gels is extremely important to our customers, so we are doing everything we can to ensure availability, despite increasing demand and supply challenges."
'No intention of profiteering'
Boots said it was limiting sales but still had stock in warehouses for online sales and high street stores.
But Well Pharmacy, which has 700 branches, said it was not limiting sales despite a surge in demand which could see some products become temporarily unavailable.
"We certainly have no intention of profiteering over the current situation by increasing prices," a spokesman added.
Amazon Marketplace and other online sales platforms have hand sanitisers available at inflated prices.
A 100ml bottle of Cuticura Total - which kills viruses as well as bacteria - is sold for £1.55 by Boots. But some Amazon sellers are offering 40ml of the brand's anti-bacterial gel for £24.99.
On social media, people posted images of empty shelves and patients with weakened immune systems called for shoppers to stop panic-buying.
Since my myelodysplasia, blood cancer diagnosis I’ve used hand sanitiser, because my neutrophils & white blood cells are low & I’m therefore prone to infection. However trying to get any from the shops has been nigh on impossible. Please stop panic buying box fulls. 🤷♂️☺️— Mark adams (@MarkyOatcake) March 2, 2020
Hand sanitiser manufacturer PZ Cussons, which makes Carex hand gel, said it was "working at full capacity in response to the exceptional demand being experienced".
Karium, which makes Cuticura hand gel, said sales have "soared" due to the coronavirus.
"We have taken immediate action to increase our production volumes, in order to meet this initial increased demand and to avoid empty shelves," said marketing director Kerry Owens.
In the House of Commons on Tuesday, Health Secretary Matt Hancock was questioned about low supplies of products such as hand sanitiser and whether the UK will have enough of medicines such as paracetamol.
"Our no-deal planning and our no-deal stockpiles are playing an important part in making sure we are fully prepared and ready," he said.