There's a warning that using a nasal decongestant spray for more than five days could make a blocked nose worse.
Using the sprays, which give short-term relief from stuffiness caused by colds, allergies and sinusitis, for longer than that could cause "rebound congestion," the Medicines and Healthcare products Regulatory Agency (MHRA) said on Friday.
"Rebound congestion", also known as rhinitis medicamentosa, is a preventable condition "where symptoms worsen and a cycle of dependency develops on the spray," the Royal College of Pharmacy (RCP) said.
The regulator said that sprays containing xylometazoline and oxymetazoline should be limited "due to adverse effects following prolonged use".
All new packaging and leaflets for such sprays and drops will include a warning not to use for longer than five days, the agency said.
But it admitted that, given it will take months to implement the change, patients should follow the new guidance in the meantime.
Thao Huynh, head of respiratory imaging and critical care at the MHRA, said: "If your nose is still blocked after five days of using a nasal spray, it could be caused by overuse of the product, rather than your original symptoms.
"Continuing to use it could make the problem worse," he said, urging people to contact a healthcare professional "about stopping use of the product and whether alternative treatments could help".
The sprays "are safe and effective treatments when used as directed," he added, while advising people to read leaflets that come with medicine and information on outer packaging.
Professor Amira Guirguis, chief scientist at the Royal College of Pharmacy, said its research "found almost 60% of pharmacists who responded believe patients are unaware of the risks of using these medicines longer than recommended."
She added: "We support clearer product information and improved packaging, alongside consistent public messaging, to improve awareness that these products are for short-term use only and to avoid preventable harm."
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In January, the RCP set the limit for using the sprays at seven days.
Sky News has contacted the RCP for comment.
(c) Sky News 2026: Nasal decongestant sprays should not be used for more than five days, medicines watchdog says

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