Nasal spray overuse can worsen blocked noses, regulators warn, as new guidance caps the recommended use of common decongestants at five days to prevent a condition that can leave patients trapped in a cycle of dependency.
MHRA issues five-day limit
The Medicines and Healthcare products Regulatory Agency (MHRA) has formally reduced the maximum usage period for nasal decongestant sprays containing xylometazoline and oxymetazoline from seven days to five. The move follows growing evidence that prolonged use risks “rebound congestion” and other “adverse effects”, the regulator said.
Thao Huynh, head of respiratory imaging and critical care at the MHRA, stressed that these products are safe and effective when used as directed. “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,” she said. “Continuing to use it could make the problem worse.”
New packaging and patient information leaflets will eventually reflect the five-day limit, but the MHRA acknowledged that these changes will take months to implement. Shops will continue to sell existing stock that may still state a seven-day limit. Despite this, patients are urged to follow the updated guidance immediately and not wait for the labels to change. Huynh advised anyone whose congestion persists after five days to stop using the spray and speak to a healthcare professional about alternative treatments.
The mechanics of rebound congestion
The condition at the heart of the warning is known medically as rhinitis medicamentosa, or rebound congestion. It develops when the nasal passages become dependent on the decongestant, creating a vicious circle: the more the spray is used, the more the nose swells when its effect wears off, prompting the patient to use the spray again for relief.
Previously an estimated 5.5 million people in the UK were considered at risk of developing dependency on these sprays. Rebound congestion can begin within 12 to 24 hours of stopping the product and, in prolonged cases, may persist for up to four weeks. In severe instances, the condition can cause chronic nasal congestion and damage to the tissues inside the nose, with some individuals requiring surgery to alleviate the effects.
A key danger, experts warn, is that patients often misinterpret rebound congestion as a return of their original cold or allergy symptoms. Instead of recognising the spray as the cause, they reach for another dose, prolonging the problem. The MHRA’s Huynh made the distinction explicit: “Rather than your original symptoms”, she said, the blocked nose may be a direct consequence of the medicine itself.
Pharmacist support and public awareness
Professor Amira Guirguis, chief scientist at the Royal College of Pharmacy, welcomed the updated guidance. She pointed to a recent survey that found almost 60% of pharmacists believed patients were unaware of the risks of using these medicines for longer than recommended. The same survey revealed that nearly three-quarters of pharmacists thought medication packaging could be clearer about usage limits, and 63% had intervened in cases of suspected overuse — often by recommending alternatives or refusing to supply the product.
“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,” Guirguis said.
The NHS advises that certain groups should be particularly cautious. People with diabetes, high blood pressure, an overactive thyroid, an enlarged prostate, glaucoma, liver or kidney problems, or heart or circulation issues should seek advice from a GP or pharmacist before using decongestants. The same applies to pregnant and breastfeeding women. Decongestants are not suitable for children under six, and children aged six to 11 should not use them for longer than five days.
For those whose congestion fails to improve after five days, or who experience frequent sinus infections, facial pain, difficulty breathing through the nose, or chronic bad breath, the survey authors advised seeking an ENT specialist’s opinion.
A range of alternatives is available that do not carry the risk of rebound congestion. Saline nasal sprays or rinses are drug-free and safe for long-term use, helping to thin mucus and moisturise nasal passages. Intranasal corticosteroid sprays, such as fluticasone and mometasone, are recommended by NICE as a first-line treatment for allergic rhinitis and do not cause dependency. Oral antihistamines like cetirizine, loratadine and fexofenadine are also suitable for longer-term relief. Non-pharmaceutical methods — warm compresses, steam inhalation from a safe distance, humidifiers, and staying hydrated — can provide additional comfort.
The MHRA also noted that patients should be cautious of “all-in-one” cold and flu remedies that combine decongestants with painkillers or antihistamines, as this can lead to accidental overdose when other medications are taken concurrently. Meanwhile, a recent US FDA advisory committee has deemed the common oral decongestant phenylephrine ineffective in pill and liquid form, though it may still work when delivered as a spray. The updated MHRA guidance does not cover oral decongestants, but the agency’s focus remains on the nasal sprays that millions of Britons rely on for short-lived relief — relief that, if pursued too long, only makes the blockage worse.