The Medicines and Healthcare products Regulatory Agency (MHRA) has issued an urgent warning that overusing common nasal decongestant sprays can actually make a blocked nose worse, not better. The regulator is imposing a strict new five-day usage limit on products containing the active ingredients xylometazoline and oxymetazoline, commonly sold over the counter for short-term relief from colds, allergies and sinusitis.
MHRA Warning: New Five‑Day Rule
The MHRA said that prolonged use of these sprays for more than five consecutive days can lead to “rebound congestion” and what it terms “adverse effects following prolonged use”. While new packaging and patient information leaflets will eventually carry the updated limit, those changes will take several months to implement. Patients are urged to follow the new five‑day guidance immediately, even if the product they already have still states a previous limit of up to seven days.
The Mechanism and Consequences of Rebound Congestion
Rebound congestion occurs when the nasal passages become more inflamed and swollen once the spray’s effect wears off. Users may mistake this worsening stuffiness for a return of their original symptoms, leading them to reach for the spray again — creating a cycle of overuse and dependency. Over time, this can escalate into a chronic condition known as rhinitis medicamentosa, which causes severe nasal congestion and potential damage to the delicate lining of the nose. Another recognised side effect is tachyphylaxis, where the medicine rapidly loses its effectiveness with repeated use.
The consequences of exceeding the recommended five days can be serious. Patients may develop a dependency, feeling they need the spray simply to breathe normally. Physical damage can occur, including turbinate hypertrophy (thickening of the nasal cushions) and abnormal function of the cilia — the tiny hairs that help clear mucus. In some cases, abrupt cessation can lead to worsening symptoms such as anxiety, sleep problems, intense congestion and headaches. Although full recovery is typical within three months with early recognition and treatment — usually involving a gradual reduction in use and alternative therapies — rare instances may require surgical intervention.
Expert Reactions and Widespread Concern
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. Instead, talk to a healthcare professional about stopping use of the product and whether alternative treatments could help.” She emphasised that these sprays “are safe and effective treatments when used as directed” and stressed the importance of reading the patient information leaflet.
Professor Amira Guirguis, chief scientist at the Royal College of Pharmacy (RPS), welcomed the update. “Our recent survey found almost 60% of pharmacists who responded believe patients are unaware of the risks of using these medicines longer than recommended,” she said. Nearly three‑quarters of pharmacists surveyed by the RPS felt that product packaging could be clearer about usage limits, and around 63% had intervened in cases of suspected overuse — either by recommending alternatives or refusing to supply the product. Separate research by ITV News and Ipsos suggested that as many as 5.5 million people in the UK may have used these sprays for longer than seven days, potentially putting themselves at risk of dependency.
Who Should Be Cautious and Safer Alternatives
The MHRA notes that these sprays are contraindicated in patients taking other oral or nasal sympathomimetic decongestants. Individuals with diabetes, high blood pressure, an overactive thyroid, an enlarged prostate, glaucoma, liver or kidney problems, heart conditions or circulation problems should seek advice from a GP or pharmacist before using them. Pregnant women should only use these sprays if advised by a healthcare professional, and swallowed decongestants are not recommended for breastfeeding women — though some nasal sprays may be safe after consultation. The sprays should not be given to children under six years old, and those aged six to 11 should not use them for longer than five days.
For those needing longer‑term relief, safer alternatives are available. NICE recommends intranasal corticosteroid sprays — such as fluticasone, mometasone and beclometasone — as a first‑line treatment for allergic rhinitis, as they reduce inflammation without causing rebound congestion. Oral antihistamines (cetirizine, loratadine, fexofenadine), saline nasal sprays or rinses, steam inhalation, warm compresses and humidifiers can also provide relief without the risks associated with decongestant overuse.
Any suspected adverse reactions related to xylometazoline or oxymetazoline should be reported to the MHRA via its Yellow Card scheme.
