Mometasone Nasal Spray for Sinusitis: How It Works and Dose
A practical guide to mometasone—what it does, the right dose, and why spray technique makes all the difference.
Part of our Sinusitis condition guide. Need a comparison? See mometasone vs beclometasone or fluticasone vs mometasone.
Get urgent help first. Call 999 or go to A&E for swelling or redness around an eye, double or reduced vision, a severe headache unlike your usual, a stiff neck, confusion or drowsiness. For a very high temperature, or if you're getting worse quickly, contact NHS 111 or your GP the same day. Online treatment isn't suitable in these situations.
Here's the headline: Less than 1% of mometasone from a nasal spray gets into your bloodstream. It acts almost entirely where it lands—which is exactly why getting the spray to land in the right place matters so much. And why it's safe for extended use in a way steroid tablets aren't.
Get Assessed for Sinusitis Treatment
Access Doctor is a UK online doctor and GPhC-registered pharmacy. Our pharmacist prescribers can recommend the right treatment for sinusitis after a short consultation, with no GP waiting room.
Start Sinusitis Consultation →Adults only online. Access Doctor’s online sinusitis service is for adults aged 18 and over. Children and young people should see their GP or, in England, a community pharmacist through NHS Pharmacy First (age 12 and over).
What is mometasone nasal spray?
Mometasone furoate is a corticosteroid—a type of steroid, but not the kind you'd take as a tablet. In its nasal spray form, it's used to reduce inflammation in the lining of your nose and sinuses. Each spray delivers 50 micrograms of the active drug.
In the UK, it's used for three main things: sinusitis, allergic rhinitis (hay fever), and nasal polyps. For sinusitis specifically, the rule is clear: if your symptoms have stuck around for about 10 days or more without budging, UK guidance says a high-dose nasal corticosteroid is the next logical step.
Important: this is off-label for sinusitis. Mometasone spray is licensed for hay fever and nasal polyps, so using it for sinusitis is officially outside its product licence. That said, NICE specifically recommends it for sinusitis and flags the off-label use right in the guideline—so it's routine, evidence-based UK practice. But a prescriber should tell you this, so we're telling you here. Our prescribers prescribe it for sinusitis following NICE guidance and will explain this during your consultation.
You might know it as Nasonex, which is the original brand. Generic mometasone sprays contain exactly the same active ingredient at the same strength and are held to the same MHRA standards.
The standout feature is its minimal systemic absorption. Less than one per cent reaches your bloodstream. The tiny amount you swallow gets broken down by your liver before it can circulate. It works where it lands and very little goes anywhere else—which is why it can be used for longer periods under clinical review.
50mcg
delivered per spray
<1%
reaches the bloodstream
1–2 wks
for the full effect to build
Not the same as mometasone cream
This catches people out all the time. Mometasone comes in completely different forms. The nasal spray is for your nose and sinuses. Mometasone creams, ointments, and scalp lotions—sold as Elocon—are topical steroids for skin conditions like eczema and psoriasis. They share a name and nothing else. Never substitute one for the other. If you're prescribed both for different reasons, keep them well apart in your medicine cabinet.
How it works in the sinuses
Corticosteroids like mometasone work by dampening the local inflammatory response. They reduce swelling, calm the inflammatory mediators, and thin out the cellular infiltration that thickens the nasal lining.
In sinusitis, the practical effect is mechanical. Your sinuses drain through openings that are only a few millimetres across. When the lining swells, those openings close. Mucus that should drain away gets trapped, pressure builds, and the stagnant mucus becomes a perfect breeding ground for bacteria.
Reduce that swelling—even by a small amount—and the openings reopen. Drainage resumes, pressure drops, and the cycle breaks. This is why a steroid spray helps whether the trigger was a virus, bacteria, or an allergen. It treats the blockage, not the cause.
This also explains why antibiotics often disappoint at day 10. By then, your symptoms are usually driven by swelling, not active infection. Killing bacteria doesn't reduce swelling. Our antibiotics guide explains the trade-off in more detail.
When it's used for sinusitis
- Acute sinusitis past day 10 without improvement—the main indication, given as a 14-day course
- Chronic rhinosinusitis—here it's the backbone of treatment, used for months alongside saline rinses
- Nasal polyps—reduces polyp size and the blockage they cause
- Allergy-driven sinus symptoms—where hay fever keeps the lining swollen
Not for the first 10 days of an acute episode. Starting a steroid spray on day two of a cold-related sinus infection is treating a problem that hasn't developed yet. Saline and pain relief are the right tools at that stage—see how to relieve sinus pressure.
Dosing for sinusitis
Mometasone dosing depends on what you're treating. This is where people often go wrong by using a hay fever dose for a sinusitis problem.
| Indication | Approach | Duration |
|---|---|---|
| Acute sinusitis, symptoms past 10 days | 2 sprays into each nostril twice a day (400 micrograms a day), adults and 12+ | 14 days |
| Chronic rhinosinusitis | Regular daily use under review | Months, with periodic review |
| Allergic rhinitis | Usually 2 sprays into each nostril once a day (200 micrograms a day) | Through the trigger season or year-round |
Always follow your label, not a general figure. The high-dose regimen for acute sinusitis is different from the standard hay fever dose. Doses also differ between products, and teenagers may be dosed differently from adults. Your prescriber specifies what applies to you. If the label and your memory disagree, the label wins.
Spray technique, step by step
Technique matters more for this medicine than almost any other. A spray that lands in the wrong place delivers almost nothing.
1
Shake and prime
Shake gently. Before first use, press the pump about 10 times into the air until a fine, even mist comes out. If you haven't used it for 14 days or more, press it twice before your next dose.
2
Clear your nose first
Blow gently, or better, use a saline rinse. The spray can't reach the lining through a layer of mucus.
3
Tilt your head slightly forward
Not back. Tilting back sends the spray straight down your throat—where most of a badly aimed dose ends up.
4
Cross hands and aim outwards
Right hand for the left nostril, left hand for the right. This angles the nozzle away from the septum and towards the outer wall, where the inflamed tissue is. Aim roughly towards the ear on that side.
5
Breathe in gently—don't sniff
A hard sniff drags the spray past the lining into your throat. A soft breath leaves it where it needs to work.
6
Don't blow your nose afterwards
Give it a few minutes to settle on the lining.
Nosebleeds are almost always a technique problem. The septum—the thin partition in the middle of your nose—is delicate and easily irritated by repeated direct spraying. Crossing hands is the simplest fix; it makes the correct angle almost automatic.
How long it takes to work
Set your expectations correctly and you're far more likely to stick with it.
- Day 1 to 2—some people notice a modest improvement. In hay fever studies, mometasone started to work within 12 hours of the first dose for some people, but many notice nothing at first.
- Day 3 to 7—gradual reduction in blockage and pressure as inflammation subsides.
- Week 2—full effect. Sense of smell often returns last.
- Beyond—in chronic sinusitis, benefit continues to accumulate over months.
It's not a decongestant. People who've used Otrivine expect instant unblocking, judge mometasone against that, and give up on day three. The two work by entirely different mechanisms on entirely different timescales. Don't waste your time—or the medication—by comparing them.
Side effects
Common—and mostly fixable by technique
- Nasal dryness or irritation
- Sneezing immediately after use
- Nosebleeds—usually from spraying at the septum
- Mild sore throat from spray running down the back
- Headache
- Small sores inside the nose
Less common
- Nasal thrush
- Altered or reduced sense of smell or taste
- Rarely, septal perforation with prolonged incorrect technique aimed at the septum
- Very rarely, raised pressure in the eye or cataract with prolonged high-dose use
Because systemic absorption is under one per cent, the side effects associated with steroid tablets aren't expected from nasal use.
Stop and seek urgent help for swelling of the face, lips or tongue, difficulty breathing, or a widespread rash. Seek prompt review for persistent or heavy nosebleeds, changes in vision, or eye pain.
Who should take extra care
- Recent nasal surgery or injury—steroids can slow healing. Tell your prescriber.
- Current nasal infection such as untreated herpes or fungal infection
- Glaucoma or cataracts, or a family history of them
- Tuberculosis or other untreated chronic infection
- Also using steroid inhalers or tablets—total steroid exposure is worth reviewing
- Pregnancy or breastfeeding—declare it so the decision is made properly
- HIV medicines containing ritonavir or cobicistat—these can increase the amount of steroid reaching the bloodstream
- Children—the sinusitis regimen applies to those aged 12 and over. Access Doctor's service is for adults 18 and over.
Practical questions
Missed a dose? Take it when you remember, unless the next is nearly due, then skip it. Don't double up.
Can I use it with saline? Yes, and rinsing first improves delivery. Rinse, then spray.
Can I use it with a decongestant? For a few days only. Decongestant sprays must not be used for more than 5 days because of rebound congestion. Older packs may still say 7 days, but the MHRA cut the limit to 5 days in April 2026.
Can I use it with antihistamines? Yes, if allergy is contributing. No interaction.
Course finished but no better? Contact your prescriber rather than continuing indefinitely. Persistent symptoms after a proper course need reassessment—see sinusitis that won't go away.
Storing it? Don't store above 25°C, and don't freeze. Use the bottle within 2 months of first opening, even if there's spray left and the printed expiry date is later.
Request Sinusitis Treatment Online
Complete a short online consultation and a GPhC-registered pharmacist prescriber will confirm the right dose and course length for you. Dispensed from our UK pharmacy. Approved before 3pm, Monday to Friday? Dispatched the same day, by Royal Mail Tracked 48, Tracked 24 or Special Delivery guaranteed by 1pm next working day: you choose. Our team can also help if you have questions about technique.
Start Sinusitis Consultation →When to get urgent help
Call 999 or go to A&E for swelling or redness around an eye, a bulging eye, double or reduced vision, a severe headache unlike your usual headaches, neck stiffness, drowsiness or confusion. These suggest infection spreading beyond the sinuses.
Contact your GP or NHS 111 the same day for a very high temperature, rapid deterioration, or if you have a weakened immune system.
UK safety and reporting side effects
Steroid nasal sprays and antibiotics for sinusitis are prescription-only medicines in the UK. Before anything is prescribed, a GPhC-registered pharmacist independent prescriber reviews your consultation, including the other medicines you take. Always read the patient information leaflet in the pack. If you’re prescribed an antibiotic, never share it or keep leftovers for another time: return any unused tablets to a pharmacy.
If you think you have had a side effect from a medicine, tell your pharmacist or doctor. You can also report it to the MHRA through the Yellow Card scheme, which helps keep medicines safe for everyone.
In England, people aged 12 and over may be able to get sinusitis treatment free from a community pharmacy through the NHS Pharmacy First service. Our private online service is for adults aged 18 and over. Our guide to private vs NHS prescriptions for sinusitis compares the two routes.
Frequently Asked Questions
How does mometasone nasal spray work for sinusitis?
Mometasone furoate is a corticosteroid that suppresses inflammation in the lining of the nose and sinuses. In sinusitis the practical problem is mechanical: the channels draining each sinus are only a few millimetres wide, so swollen lining closes them and traps mucus. Reducing that swelling reopens the channels and lets the sinuses drain. This is why it helps whether the original trigger was viral, bacterial or allergic, because it targets the blockage rather than an organism.
What is the dose of mometasone nasal spray for sinusitis?
For acute sinusitis that has lasted around 10 days or more without improving, NICE recommends 2 sprays into each nostril twice a day (400 micrograms a day) for 14 days, for adults and children aged 12 and over. This is double the usual hay fever dose. Each spray delivers 50 micrograms. Always follow the dose and duration on your label, as your prescriber may adjust it for you.
Is mometasone nasal spray licensed for sinusitis?
No. In the UK it's licensed for hay fever, year-round allergic rhinitis and nasal polyps. NICE recommends it for sinusitis that has lasted around 10 days or more, which is an off-label use. Our prescribers prescribe it for sinusitis following NICE guidance and will explain this during your consultation.
How long does mometasone take to work for sinusitis?
Some people notice an improvement within a day or two, but the full anti-inflammatory effect builds over one to two weeks of consistent daily use. It isn't a decongestant and won't unblock your nose within minutes. Stopping after three days because nothing dramatic has happened is the single most common reason it appears not to work. Use it every day for the full course before judging whether it has helped.
Is mometasone nasal spray the same as Elocon cream?
No. Both contain mometasone furoate, but they're completely different products for completely different conditions. The nasal spray is formulated to be delivered to the lining of the nose for sinusitis and allergic rhinitis. Mometasone creams, ointments and scalp preparations such as Elocon are topical steroids for skin conditions like eczema and psoriasis. They aren't interchangeable in any circumstances, and neither should ever be substituted for the other.
What are the side effects of mometasone nasal spray?
The common side effects are local rather than systemic: nasal dryness or irritation, sneezing shortly after use, a mild sore throat and nosebleeds. Nosebleeds are usually caused by aiming the spray at the septum, the thin partition in the middle of the nose, and improve when technique is corrected. Headache is also common. Because under one per cent is absorbed into the bloodstream, the side effects associated with steroid tablets aren't expected with nasal use.
Can you use mometasone nasal spray long term?
Yes, under clinical review. Its very low systemic absorption is precisely why it's suitable for extended use, and for chronic sinusitis it's commonly used for months rather than weeks. This is quite different from steroid tablets, which carry systemic effects. For acute sinusitis the course is usually 14 days. If you also use a steroid inhaler for asthma or take steroid tablets, tell your prescriber so your total steroid exposure can be considered.
Can I use mometasone nasal spray in pregnancy?
This needs a clinician who knows your pregnancy. Steroid nasal sprays are absorbed only minimally into the bloodstream, which is reassuring, and they're sometimes used in pregnancy where the benefit justifies it. That's a decision for your midwife, GP or prescriber rather than something to start yourself. Always declare pregnancy, possible pregnancy or breastfeeding at the point of consultation so the right choice can be made.
Completing the treatment
Mometasone works best alongside daily saline rinsing, which clears mucus so the spray can reach the lining. Access Doctor supplies mometasone nasal spray for sinusitis and beclometasone nasal spray and, where genuinely indicated, antibiotics such as doxycycline or clarithromycin, after a short online consultation with a GPhC-registered pharmacist prescriber. See the full range of sinusitis treatment online.
Steroid spray · Rx
Mometasone Nasal Spray for Sinusitis
Under 1% systemic absorption. Suitable for extended use under review.
View product →Steroid spray · Rx
Beclometasone Nasal Spray for Sinusitis
Long-established alternative steroid nasal spray.
View product →Antibiotic · Rx
Phenoxymethylpenicillin for Sinusitis
First-choice antibiotic for bacterial sinusitis: 500mg four times a day for 5 days. Prescribed after an online consultation.
View product →Antibiotic · Rx
Clarithromycin Tablets for Sinusitis
Alternative antibiotic where penicillin can't be used.
View product →References
- National Institute for Health and Care Excellence. Sinusitis (acute): antimicrobial prescribing (NG79). nice.org.uk
- Joint Formulary Committee. British National Formulary: mometasone furoate (nasal). bnf.nice.org.uk
- NHS. Steroid nasal sprays. nhs.uk
- Electronic Medicines Compendium. Mometasone furoate nasal spray SmPC. medicines.org.uk
- NICE Clinical Knowledge Summaries. Sinusitis. cks.nice.org.uk
- European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS). rhinologyjournal.com
- NHS. Nasal polyps. nhs.uk
Medical disclaimer: This article is for informational purposes only and doesn't constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.