Pharmacy bosses have warned of a shortage of cough and cold medicines, with some pharmacists "struggling to obtain the very basic" supplies.
Throat lozenges, cough mixtures, and some painkillers are among the over-the-counter medicines in short supply, according to the Association of Independent Multiple Pharmacies.
The industry group warned of supply issues of both branded and unbranded medicines to treat seasonal illnesses.
It comes after the UK Health Security Agency warned that winter illnesses, including flu and COVID-19, continue to circulate at "high levels".
Officials have urged unwell adults to wear face masks to stem the spread of infections, while parents have been urged to keep children with a fever off school.
Chief executive Leyla Hannbeck said that pharmacists were "struggling to obtain the very basic, most common cold and flu medicine".
She said: "This isn't just the branded medicines, it is also simple things like throat lozenges, cough mixtures, or painkillers - particularly the ones that are soluble.
"The demand has been high because this season we've seen higher cases of colds and flu and people are obviously trying very hard to look after themselves and making sure that they use the relevant products to manage the symptoms.
"And that has led to a shortage of these products in terms of us not being able to obtain them.
"On the front line, it is very difficult because we're seeing these shortages but those people who are in charge of supporting us with it are denying it."
High street chain Superdrug said that it had seen a huge demand for cough and cold medicines.