How long should you use a decongestant nasal spray? The new five-day warning explained

What causes nasal congestion?

Nasal congestion occurs when your nasal passages become blocked or ‘bunged up’ due to swollen blood vessels and inflamed tissues inside your nose. It’s often accompanied by excess mucus during a cold or flu.

Triggers include viral infections, environmental dryness, structural obstructions - for example, nasal polyps - and allergic reactions such as hay fever or allergic rhinitis.

There are various over-the-counter treatments available to help manage nasal congestion, depending on the underlying cause. If your condition does not require treatment from a health professional, it will usually clear up on its own. In these cases, treatment focuses on managing your symptoms until the condition passes.

One of the most widely used options for relieving nasal congestion is decongestant drops and sprays.

In the UK, pharmacy-bought nasal decongestants include xylometazoline, oxymetazoline, and ephedrine. These treatments work by narrowing swollen blood vessels in your nasal passages, helping to quickly reduce congestion and make it easier to breathe.

What happens if you overuse nasal decongestant sprays?

We are now entering the first cold and flu season under the new MHRA guidelines, so it’s important to be mindful of how often you use these medicines.

Mr Samit Unadkat, a London-based ENT surgeon, warns that overusing nasal sprays can leave you feeling more congested rather than less. In rare cases, prolonged overuse can also cause lasting damage to the lining of your nose.

He explains that because these sprays are so effective and fast-acting, often providing relief within minutes, it is easy to become reliant on them. However, with repeated use, your nasal tissues can become less responsive to the treatment.

As the effects of each dose wear off, the lining of your nose can swell even more than before, creating a vicious cycle of increasing congestion, more frequent spray use, and, ultimately, even more blockage.

"This is called rhinitis medicamentosa - commonly known as rebound congestion," says Unadkat. "It is not an addiction in the same way as nicotine or opioids, but people can develop a powerful physical and psychological reliance on the bottle."

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The potential side effects of overusing nasal sprays

When used sensibly and only for a few days, decongestant sprays are generally safe and effective. However, Unadkat warns that using them well beyond the recommended five-day limit can increase your chance of side effects and complications.

Unadkat concludes that most cases settle once you stop using the spray. At this point, the underlying cause of the congestion - such as an allergy, lingering infection, or structural issue such as a deviated septum - can be properly assessed and treated.

He adds that saline rinses and, where appropriate, a steroid nasal spray may be a better long-term option than repeatedly reaching for a decongestant.

"Used correctly, decongestants are safe and effective," he says. "The rule is simple - five days, then stop. If your nose is still blocked, the spray may no longer be treating the issue. It may have become part of it."