Steroid Nasal Spray vs Antibiotics for Sinusitis: Which Is Better?
They treat two different problems. Which one you need depends almost entirely on how long your symptoms have lasted.
Part of our Sinusitis condition guide.
The headline: Antibiotics kill bacteria. Steroid sprays reduce swelling. By day 10 of a sinus infection, the thing keeping you unwell is usually swelling, not bacteria—which is why the spray is often the better answer even though the antibiotic feels like the stronger one.
Find Out Which You Need
Access Doctor is a GPhC-registered UK pharmacy. A pharmacist independent prescriber reviews your symptoms and how long they've lasted, then recommends the treatment that actually fits—without a GP appointment.
View Sinusitis Treatments →They treat two different problems
The question "which is better" assumes they're competing at the same job. They're not.
A sinus infection has two components. There's whatever triggered it—usually a virus, occasionally bacteria. And there's the inflammation that follows, which swells the lining and closes the narrow channels draining each sinus.
That second part is what you actually feel. The pressure over your cheeks, the blocked nose, the lost sense of smell: all of it comes from mucus trapped behind swollen, closed drainage openings.
Antibiotics act on the first component, and only when bacteria are involved. Steroid sprays act on the second, whatever caused it.
10 days
before either is normally considered
14 days
steroid spray course NICE suggests
5 days
antibiotic course, where indicated
What antibiotics do, and when they help
Antibiotics kill or halt bacteria. For sinusitis that means the organisms behind genuine bacterial infection, most often Streptococcus pneumoniae and Haemophilus influenzae.
The complication is that acute sinusitis is overwhelmingly viral. Only a small proportion develop a secondary bacterial infection, which is why NICE guidance advises against antibiotics for symptoms lasting fewer than 10 days.
When an antibiotic is the right answer
- Double sickening—you improved around day five or six, then clearly got worse again
- Systemically very unwell—genuinely ill rather than uncomfortable, with high fever
- Symptoms past 10 days alongside features suggesting bacterial infection
- High risk of complications—significant immunosuppression, poorly controlled diabetes
Where indicated, phenoxymethylpenicillin is UK first choice, with doxycycline or clarithromycin for penicillin allergy. Our guide on antibiotics for a sinus infection covers the decision in full.
What steroid nasal sprays do, and when they help
Corticosteroids applied to the nasal lining suppress the local inflammatory response, reducing the swelling that narrows the sinus openings.
The consequence is mechanical. Each sinus drains through an opening only a few millimetres across. Reduce the mucosal thickness even modestly and those openings reopen, trapped mucus drains, and pressure falls.
When a spray is the right answer
- Symptoms past day 10 without improving—the main indication, as a 14-day course
- Chronic sinusitis—here it's the mainstay, used for months
- An allergic component keeping the lining swollen
- Nasal polyps obstructing drainage
Access Doctor supplies mometasone nasal spray for sinusitis and beclometasone nasal spray for sinusitis. Our comparison of the best nasal spray for sinusitis sets out the differences between them.
Side-by-side comparison
| Steroid nasal spray | Antibiotic | |
|---|---|---|
| Targets | Inflammation blocking drainage | Bacteria, if present |
| Works if the cause is viral | Yes—inflammation is inflammation | No |
| Works if the cause is bacterial | Yes, on the swelling component | Yes, on the infection |
| Main indication | Symptoms past 10 days | Likely bacterial infection |
| Course length | 14 days acute; months in chronic | 5 days |
| Onset | Builds over 1–2 weeks | 48–72 hours if bacterial |
| Common side effects | Nasal dryness, irritation, nosebleeds | Nausea, diarrhoea, thrush |
| Systemic absorption | Minimal | Full |
| Resistance risk | None | Yes |
| Suitable long term | Yes, under review | No |
| Role in chronic sinusitis | Mainstay | Very limited |
What NICE NG79 recommends, and in what order
1
Under 10 days: neither
No antibiotic and no steroid spray. Self-care only—saline rinses, steam, regular pain relief. Most sinusitis resolves in this window with nothing prescribed.
2
10 days or more, not improving: consider the spray
A high-dose nasal corticosteroid for 14 days, for adults and children aged 12 and over. This is the step most people at this stage actually need. NICE flags this use as off-label—see the note below.
3
Bacterial infection likely, or systemically very unwell: the antibiotic
A back-up prescription is often used at this point—held, and started only if things worsen or fail to improve.
4
Not oral steroids
Prednisolone and other oral corticosteroids are not recommended for acute sinusitis. See below.
Note the ordering. The steroid spray appears before the antibiotic in the guidance, not after it. That surprises most people, and it's the single most useful thing on this page.
The spray step is off-label use. Steroid nasal sprays are licensed in the UK for allergic rhinitis and nasal polyps, not for sinusitis, so prescribing one for a sinus infection sits outside the product licence. NICE recommends it regardless and flags it as off-label in the guideline itself—it's routine, well-evidenced UK practice. But you're entitled to be told when a medicine is used this way, so we're saying it plainly.
Why day 10 changes the answer
Early in a sinus infection, a virus is actively replicating and inflammation is building. Neither treatment has much to offer—the antibiotic has no target, and the spray hasn't had time to work.
By day 10, the picture has usually shifted. In most people the original virus has been cleared or is clearing. What remains is a self-sustaining mechanical problem: swollen lining, closed drainage openings, trapped mucus, continued inflammation from the stagnation itself.
At that point an antibiotic addresses something that may no longer be there, while a steroid spray addresses exactly what is keeping you unwell.
This explains a common experience. People who finally get an antibiotic at day 12 and feel no better often conclude it was the wrong antibiotic. Usually it was the wrong class of treatment—the problem was inflammation, not infection.
Why prednisolone isn't standard for sinusitis
Oral steroids come up frequently, partly because they sound more powerful than a spray.
UK guidance does not recommend oral corticosteroids such as prednisolone for acute sinusitis. There are two reasons.
First, the evidence doesn't support meaningful benefit in acute sinus infection. Second, oral steroids act throughout the body, and even short courses carry effects a nasal spray doesn't: raised blood sugar, mood and sleep disturbance, stomach irritation, and with repeated courses more serious risks.
A steroid nasal spray delivers the anti-inflammatory effect precisely where it's needed, with under one per cent absorbed systemically. For a problem confined to the nasal and sinus lining, that's the better trade by a wide margin.
| Steroid nasal spray | Oral steroid (prednisolone) | |
|---|---|---|
| Where it acts | Nasal and sinus lining | Whole body |
| Systemic absorption | Under 1% | Complete |
| Recommended for acute sinusitis? | Yes, past day 10 | No |
| Side effect profile | Local: dryness, nosebleeds | Systemic: blood sugar, mood, sleep, stomach |
| Suitable for repeated use | Yes, under review | No |
Where oral steroids do have a role: specialists occasionally use short courses in severe chronic rhinosinusitis, particularly with nasal polyps, usually alongside ENT input. That's a specialist decision made with the whole picture in view, not routine treatment for a sinus infection.
Access Doctor does not supply oral steroids for sinusitis, because they aren't the appropriate treatment for it.
Can you use both together?
Yes, and it's common where both are indicated.
There's no interaction between them. They act by entirely different mechanisms in entirely different places—one systemically against bacteria, one locally against inflammation.
The typical combined situation is someone at day 12 who improved and then clearly worsened, with facial pain and fever: the antibiotic tackles the bacterial infection while the spray reopens the drainage that the infection depends on.
Alongside either or both, saline rinsing and regular pain relief continue to matter—see how to relieve sinus pressure.
Chronic sinusitis: the answer changes again
For symptoms lasting 12 weeks or more, the comparison stops being close.
Chronic rhinosinusitis is a persistent inflammatory condition rather than an ongoing infection. The steroid nasal spray becomes the mainstay, used consistently for months alongside daily saline irrigation. Antibiotics have very little role.
Repeated antibiotic courses for chronic sinus symptoms are a pattern worth breaking. They typically produce brief or no benefit while adding side effects and resistance pressure. If you've had several courses in a year without lasting improvement, that's diagnostic information—see acute vs chronic sinusitis and sinusitis that will not go away.
How a prescriber actually decides
| Your situation | Usual answer |
|---|---|
| Under 10 days, improving | Neither. Self-care. |
| 10+ days, not improving, not systemically unwell | Steroid nasal spray, 14 days |
| Improved then clearly worse (double sickening) | Antibiotic, often with the spray |
| Systemically very unwell | Antibiotic, assessed urgently |
| Under 10 days but severe with high fever | Assessment now, regardless of day count |
| 12 weeks or more | Steroid spray long term, plus investigation |
| Allergic pattern alongside | Spray, plus treating the allergy |
| Red flags | Emergency care |
Get the Right Treatment for Where You Are
Complete a short online consultation and a GPhC-registered pharmacist independent prescriber will assess how long your symptoms have lasted and recommend a steroid nasal spray, an antibiotic, both, or continued self-care. Dispensed from our UK pharmacy.
View Mometasone Nasal Spray →Red flags needing emergency care
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 override any treatment comparison and need emergency assessment.
Contact your GP or NHS 111 the same day if you have a very high temperature, are deteriorating rapidly, or have a weakened immune system.
Frequently Asked Questions
Antibiotics or steroids for sinusitis: which is better?
Neither is better in general, because they treat different problems. Antibiotics kill bacteria, which helps only in the minority of sinus infections that are genuinely bacterial. Steroid nasal sprays reduce the swelling that blocks sinus drainage, which is what actually sustains symptoms in most people beyond the first week. For symptoms lasting 10 days or more without improvement, a steroid nasal spray is usually the more appropriate choice.
Why would a steroid spray work better than an antibiotic?
Because by day 10 the problem is usually mechanical rather than infective. The channels draining each sinus are only a few millimetres wide, so swollen lining closes them and traps mucus, and that trapped pressure is what you feel. Reducing the swelling reopens the channels regardless of what triggered the episode. An antibiotic kills bacteria but does nothing to the swelling, which is why people often report that a course made little difference.
Can you take a steroid nasal spray and antibiotics together?
Yes. They work in completely different ways and there is no interaction between them, so where both are clinically indicated they are commonly used together. The antibiotic addresses a bacterial infection while the spray reduces the inflammation blocking drainage. Your prescriber will decide whether you need one, the other or both, based on how long symptoms have lasted and how unwell you are.
Are oral steroids like prednisolone used for sinusitis?
Not for acute sinusitis. UK guidance does not recommend oral corticosteroids such as prednisolone for acute sinus infections, because the evidence does not support a meaningful benefit and systemic steroids carry side effects that a nasal spray does not. Short courses are occasionally used by specialists in severe chronic rhinosinusitis, particularly with nasal polyps, but that is a specialist decision rather than routine treatment for a sinus infection.
How long does prednisolone take to work for sinusitis?
This question comes up often, but prednisolone is not standard treatment for acute sinusitis in the UK, so the more useful answer is that it is not usually the right medicine for the problem. Where a specialist prescribes a short course in severe chronic rhinosinusitis with nasal polyps, effects are typically noticed within a few days. For an ordinary sinus infection, a steroid nasal spray applied directly to the lining is the appropriate route.
How long does each treatment take to work?
An antibiotic, where the infection is genuinely bacterial, usually produces noticeable improvement in facial pain and fever within 48 to 72 hours. A steroid nasal spray works more gradually: some people notice a difference within a day or two, but the full anti-inflammatory effect builds over one to two weeks of consistent daily use. Expecting a spray to act like a decongestant is the commonest reason people abandon it too early.
Which treatment is used for chronic sinusitis?
For chronic sinusitis lasting 12 weeks or more, the steroid nasal spray is the mainstay and antibiotics have very little role. Chronic sinusitis is a persistent inflammatory condition rather than an ongoing infection, so a spray used consistently over months alongside saline irrigation addresses the actual problem. Repeated antibiotic courses in chronic sinusitis typically produce brief or no benefit while adding side effects and resistance pressure.
Completing the treatment
Whichever treatment fits your situation, Access Doctor supplies it after a short online consultation reviewed by a GPhC-registered pharmacist independent prescriber. No GP appointment is needed and orders are dispensed from our UK pharmacy. See the full range on the sinusitis treatment page.
Steroid spray · Rx
Mometasone Nasal Spray for Sinusitis
Usually the more appropriate option for symptoms past day 10.
View product →Steroid spray · Rx
Beclometasone Nasal Spray for Sinusitis
Alternative steroid nasal spray, equally effective.
View product →Antibiotic · Rx
Phenoxymethylpenicillin for Sinusitis
Where bacterial infection is genuinely likely.
View product →Antibiotic · Rx
Doxycycline Capsules for Sinusitis
Alternative where penicillin cannot be used.
View product →References
- National Institute for Health and Care Excellence. Sinusitis (acute): antimicrobial prescribing (NG79). nice.org.uk
- NICE Clinical Knowledge Summaries. Sinusitis. cks.nice.org.uk
- Joint Formulary Committee. British National Formulary: mometasone furoate (nasal). bnf.nice.org.uk
- Joint Formulary Committee. British National Formulary: prednisolone. bnf.nice.org.uk
- NHS. Steroid nasal sprays. nhs.uk
- NHS. Steroid tablets. nhs.uk
- European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS). rhinologyjournal.com
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.