Mometasone furoate is a potent corticosteroid nasal spray prescribed for hay fever (allergic rhinitis) and nasal polyps. In the UK, it is most commonly known by the brand name Nasonex. It is widely regarded by allergists as one of the most effective nasal sprays available, with strong clinical evidence supporting its use.
How Does It Work?
Mometasone works by reducing inflammation in the nasal passages. When pollen or other allergens enter your nose, they trigger an immune response that causes swelling, mucus production, and irritation. Mometasone suppresses this inflammatory cascade, providing relief from congestion, sneezing, runny nose, and nasal itching.
Unlike antihistamines, which block one specific chemical (histamine), corticosteroid sprays address multiple pathways of the allergic response, which is why they are often more effective for nasal symptoms.
Dosage and How to Use It
The standard dose for adults and children over 12 is:
- Two sprays into each nostril once daily (200 micrograms total)
- Once symptoms are controlled, your doctor may reduce this to one spray per nostril daily
For best results:
- Use it at the same time each day
- Point the nozzle slightly away from the centre of your nose (the septum) to reduce the risk of nosebleeds
- Do not tilt your head back — keep it level or slightly forward
- Start using it two weeks before pollen season for optimal protection
How Long Does It Take to Work?
Some people notice improvement within 12 hours of the first dose, but mometasone typically reaches its full effect after 1–2 weeks of regular use. This is why consistency matters — skipping doses reduces its effectiveness.
Side Effects
Mometasone is considered very safe for seasonal and year-round use. The most commonly reported side effects are:
- Nosebleeds: Occur in around 5–10% of users, usually mild
- Nasal irritation or dryness
- Headache: Uncommon
- Sore throat: Occasionally reported
Systemic absorption is extremely low with mometasone, meaning it has negligible effects on the rest of the body at recommended doses. This makes it suitable for long-term use under medical guidance.
Getting Mometasone in the UK
Mometasone nasal spray is prescription only in the UK. You can obtain it from your GP, or through MHRA-regulated online pharmacy services. It is available on the NHS and costs the standard prescription charge of £9.90 in England, or is free in Scotland, Wales, and Northern Ireland.