Mometasone

What it is

Mometasone furoate is a synthetic corticosteroid designed to act strongly where it is applied and to be cleared quickly once it reaches the bloodstream. It is sold as an aqueous nasal spray for hay fever and nasal polyps, as a dry-powder or aerosol inhaler for asthma, and as a 0.1% cream, ointment and lotion for inflammatory skin conditions. It is broken down mainly by the liver enzyme CYP3A4. In the United States the nasal spray is now also sold over the counter.

What the research says

The evidence is route-specific. For allergic rhinitis, a network meta-analysis of 26 trials ranked mometasone the most effective intranasal steroid for seasonal disease, with a standardised mean difference of about -0.47 against placebo - a real but modest effect - while for perennial disease it ranked last of five. For nasal polyps, two placebo-controlled trials show statistically significant but small shrinkage in polyp size and congestion. For asthma, a small meta-analysis of four paediatric trials found improved lung function. For glue ear in children, a well-conducted UK primary-care trial found it no better than placebo, and the authors concluded it is unlikely to be effective. The commonest harm is nosebleeds, raised from about 6% to 11% in the trials; the topical cream caused measurable suppression of the body's own cortisol in about 16% of infants treated over a large skin area.

Evidence grade: Well established.

How it works

Drug class: Synthetic corticosteroid (glucocorticoid); high-potency topical, with intranasal and inhaled formulations designed for low systemic bioavailability

Mometasone furoate binds the glucocorticoid receptor inside cells at the place it is applied - the lining of the nose, the airways or the skin - and this shuts down the genes that drive inflammation, so swelling, mucus, itching and redness fall. It is designed to be poorly absorbed and quickly broken down by liver CYP3A4, which is why systemic effects are less common than with oral steroids but not absent when a lot is used over a large area or for a long time. (Source 1)

What it is used for

• In a network meta-analysis of 26 randomised trials, mometasone ranked highest among licensed-dose intranasal steroids for seasonal allergic rhinitis (SMD -0.47) but ranked last of five for perennial disease (SMD -0.28). Intranasal steroids as a class beat oral antihistamines on nasal symptoms (SMD -0.70). Evidence: established. (Source 2)
• Two placebo-controlled trials show benefit, but the absolute size is small: in a 748-patient trial the difference in nasal congestion over 4 weeks was -0.14 points and in total polyp size score at 16 weeks -0.30 points. An earlier 298-patient trial reported 74.3% versus 46.8% improved on the investigator's congestion score. Nosebleeds were significantly more common on drug. Evidence: established. (Source 3)
• A meta-analysis of four paediatric randomised trials found improved lung function versus placebo with no increase in overall adverse events, and a comparative meta-analysis of six trials in moderate-to-severe asthma found it at least as good as other inhaled steroids at equipotent doses. The paediatric evidence base is small. Evidence: established. (Source 4)
• Approved for corticosteroid-responsive dermatoses. In randomised crossover knemometry it did not slow short-term lower-leg growth in school-age children with eczema, but in the manufacturer's trial programme signs of skin thinning were documented and about 16% of infants aged 6 to 23 months treated over a mean 41% of body surface showed adrenal suppression. Evidence: established. (Source 5)
• A double-blind randomised placebo-controlled trial of mometasone furoate 50 mcg daily for three months in 217 children aged 4 to 11 found cure rates of 41% on drug versus 45% on placebo at one month, with the difference favouring placebo. The trial concluded topical steroids are unlikely to be effective for this condition. Evidence: not-supported. (Source 6)
• Intranasal mometasone is used as an alternative to adenoidectomy and small trials show symptom improvement, but the randomised evidence is thin: a meta-analysis of five trials with 416 children compared mometasone alone against mometasone plus montelukast rather than against placebo, and none of the trials assessed montelukast's neuropsychiatric harms. Evidence: limited. (Source 7)

Interactions

• Strong CYP3A4 inhibitors (long-term ketoconazole, ritonavir, cobicistat-containing products, clarithromycin, itraconazole and others) (label): These block the liver enzyme that clears mometasone, so more of it stays in the body and steroid side effects such as adrenal suppression and Cushing-like changes become possible even from a nasal spray or inhaler. (Source 1)
• Grapefruit and grapefruit juice (theoretical): Grapefruit inhibits CYP3A4, the enzyme that breaks mometasone down, so it could in theory raise systemic exposure. We found no grapefruit-mometasone study, and because the nasal and inhaled forms are absorbed poorly to begin with the practical importance is unknown - the label states that no formal interaction studies were done at all. (Source 1)
• St John's wort (Hypericum perforatum) (theoretical): St John's wort induces CYP3A4 and would be expected to speed mometasone's clearance. Neither the nasal spray nor the inhaler label addresses CYP3A4 inducers at all - they discuss only inhibitors - so this is inference from the metabolic pathway with no measured data. (Source 1)
• Alcohol (label): We found no documented interaction between alcohol and mometasone by any route, and none is described on the labels. The nasal spray label states that no formal drug interaction studies were performed, so absence of a listed interaction is absence of testing rather than evidence of safety. (Source 1)
• Other corticosteroids by any route - oral, injected, inhaled, intranasal or topical (label): Systemic steroid exposure adds up across routes. Someone using a nasal spray, an inhaler and a strong steroid cream at once can reach a total exposure that matters, which is the mechanism behind reported adrenal suppression, slowed growth in children and bone density loss. (Source 8)
• Live and live attenuated vaccines, and exposure to chickenpox or measles (label): Mometasone is designed for low systemic absorption, so this is mainly a concern at high doses or in combination with other steroids; the inhaler label carries a specific warning about immunosuppression and infection risk. (Source 9)

Stopping it

• After topical use, the body's own cortisol production usually recovers quickly once the steroid stops, but occasionally symptoms of steroid insufficiency appear and need systemic steroid cover - so an abrupt stop after heavy or prolonged use is not automatically safe. (Source 10)
• If testing shows the adrenal axis is suppressed during topical mometasone, the documented approach is to withdraw the drug gradually, reduce how often it is applied, or move to a weaker steroid. (Source 10)
• For the inhaler, if steroid excess or adrenal suppression appears, the dose is reduced slowly in the way systemic steroids are tapered rather than stopped, because asthma also has to stay controlled. (Source 8)
• For glue ear, the relevant finding about stopping is that the condition largely resolves on its own: in the randomised trial high rates of natural resolution occurred within one to three months in both arms, so apparent improvement after a course cannot be attributed to the drug. (Source 6)
• We found no literature describing a withdrawal syndrome, dependence or rebound rhinitis specific to stopping intranasal mometasone. The over-the-counter nasal spray labelling instead limits paediatric duration because of the growth signal, advising a doctor be consulted if a child needs it for more than two months a year. (Source 11)

What goes wrong

Nosebleeds are the clearest harm of mometasone nasal spray, roughly doubling against placebo in the trial programme. (Source 12)

• Official position, Moderate certainty.
• Size: 2,103 allergic rhinitis patients on 200 mcg/day versus 1,671 on vehicle placebo; 594 adults in the nasal polyp studies.
• Who: adults and children 12 and older with allergic rhinitis; adults 18 to 86 with chronic rhinosinusitis with nasal polyps.
• How long: controlled trials up to 4 months for polyps; 350 rhinitis patients treated a year or longer.
• Result: epistaxis or blood-tinged mucus 11% versus 6% in allergic rhinitis; in nasal polyps epistaxis 9% on 200 mcg once daily and 13% on 200 mcg twice daily versus 5% on placebo; nasal ulcers and nasal and oral candidiasis reported mainly after more than 4 weeks.
• Funding: manufacturer document (regulatory label)

The overall incidence of adverse reactions for patients treated with mometasone furoate nasal spray was comparable to patients with the placebo except for epistaxis, which was 9% for 200 mcg once daily, 13% for 200 mcg twice daily, and 5% for the placebo.

Across 72 randomised trials, intranasal steroids raised the risk of nosebleeds by about half, and mometasone was among the agents with the highest risk. (Source 13)

• Meta-analysis, Moderate certainty.
• Size: 72 randomised trials of 949 identified studies.
• Who: patients treated with intranasal corticosteroids for allergic rhinitis.
• How long: varied; trials reporting epistaxis incidence.
• Result: overall relative risk of epistaxis 1.48 (95% CI 1.32-1.67) for all intranasal corticosteroids; mometasone furoate named among the highest-risk agents alongside beclomethasone hydrofluoroalkane, fluticasone furoate and fluticasone propionate.
• Funding: not stated in the abstract.

Meta-analysis demonstrated an overall relative risk of epistaxis of 1.48 (95% CI, 1.32-1.67) for all INCSs.

Nasal septum perforation has been reported with mometasone nasal spray, along with candida infection of the nose and throat. (Source 14)

• Official position, Low certainty.
• Size: not quantified; spontaneous and trial reports.
• Who: people using intranasal corticosteroids, particularly for several months or longer.
• How long: long-term use.
• Result: nasal septum perforation, localised Candida albicans infection of nose and pharynx, and impaired wound healing after nasal surgery, ulcers or trauma.
• Funding: manufacturer document (regulatory label)

Instances of nasal septum perforation occurred in patients following the nasal application of corticosteroids, including mometasone furoate nasal spray.

Topical mometasone cream suppressed the body's own cortisol production in about one in six infants treated over a large area of skin. (Source 15)

• Official position, Moderate certainty.
• Size: pediatric subjects aged 6 to 23 months with normal baseline adrenal function; follow-up testing available for 5.
• Who: infants and toddlers treated over a mean 41% of body surface area (range 15% to 94%)
• How long: approximately 3 weeks.
• Result: HPA axis suppression in approximately 16%; 1 of the 5 retested 2 to 4 weeks later was still suppressed; long-term use has not been studied in this age group.
• Funding: manufacturer document (regulatory label)

Mometasone furoate cream caused HPA axis suppression in approximately 16% of pediatric subjects ages 6 to 23 months

Signs of skin thinning were documented in the mometasone cream trial programme, and skin atrophy is listed among its most common adverse reactions. (Source 16)

• Official position, Low certainty.
• Size: 319 subjects in controlled trials, 74 children aged 2 to 12, 182 children aged 6 months to 2 years, and 97 subjects assessed for atrophy signs.
• Who: adults and children using mometasone furoate cream.
• How long: controlled clinical trials; duration not stated.
• Result: overall adverse reaction rate 1.6% in adults and about 7% in children aged 2 to 12; among 97 subjects assessed, shininess in 4, loss of elasticity in 4, loss of normal skin markings in 4, telangiectasia in 1, thinness in 1 and bruising in 1.
• Funding: manufacturer document (regulatory label)

The following signs of skin atrophy were also observed among 97 subjects treated with mometasone furoate cream in a clinical trial: shininess, 4; telangiectasia, 1; loss of elasticity, 4; loss of normal skin markings, 4; thinness, 1; and bruising, 1.

At a total daily dose of 200 mcg, inhaled mometasone slowed growth velocity in young children by about 0.7 cm a year. (Source 17)

• Randomized trial, Moderate certainty.
• Size: 187 children randomised to one of three mometasone regimens or placebo.
• Who: children aged 4 to 9 with mild persistent asthma.
• How long: 52 weeks of treatment plus 3 months of follow-up.
• Result: 100 mcg once daily -0.10 cm/year (p = 0.76, not significant); 100 mcg twice daily -0.64 cm/year (p = 0.10); 200 mcg once daily -0.70 cm/year (p = 0.02, significant); no drug-related effect on plasma or 12-hour urinary cortisol.
• Funding: not stated in the abstract.

When the effect of a total daily dose of 200 μg MF-DPI on growth velocity was examined, no significant effect was demonstrated for MF-DPI 100 μg BID compared with placebo (-0.64 ± 0.39 cm/y, p = 0.10), although the change in mean growth velocity with MF-DPI 200 μg QD AM reached statistical significance (-0.70 ± 0.29 cm/y, p = 0.02).

Across the inhaled corticosteroid class, more than 12 months of use slowed growth velocity by about half a centimetre a year and left adult height about 1.2 cm shorter in the best-quality trial. (Source 18)

• Meta-analysis, Moderate certainty.
• Size: 23 studies (20 randomised trials, 3 observational); 16 randomised trials in the growth velocity meta-analysis.
• Who: children with asthma using inhaled corticosteroids for more than 12 months.
• How long: one year or longer; one high-quality trial followed to final adult height.
• Result: growth velocity mean difference -0.48 cm/year (95% CI -0.66 to -0.29) at one year, with a dose-response effect in three trials; final adult height -1.20 cm (95% CI -1.90 to -0.50) with budesonide versus placebo - about a 0.7% reduction.
• Funding: not stated in the abstract; class-level evidence, not mometasone-specific.

Meta-analysis of 16 RCTs showed that ICS use significantly reduced growth velocity at one year follow-up (mean difference -0.48 cm/year (95% CI -0.66 to -0.29))

Two years of inhaled mometasone 220 mcg twice daily significantly reduced lumbar spine bone mineral density compared with placebo. (Source 19)

• Randomized trial, Low certainty.
• Size: 103 patients in the 220 mcg study and 87 in the 440 mcg study.
• Who: adults aged 18 to 50 with asthma previously maintained on bronchodilators.
• How long: 2 years, double-blind.
• Result: lumbar spine BMD change -0.015 (-1.43%) on mometasone 220 mcg twice daily versus +0.002 (0.25%) on placebo; in the second study at 440 mcg twice daily the change was -0.018 (-1.57%) versus -0.006 (-0.43%) and was not statistically significant - a result that does not follow a dose gradient.
• Funding: manufacturer document (regulatory label) reporting manufacturer trials.

treatment with ASMANEX TWISTHALER 220 mcg twice daily resulted in significant reductions in lumbar spine (LS) BMD at the end of the treatment period compared to placebo

Glaucoma, raised eye pressure and cataracts were reported in a small number of patients on inhaled mometasone. (Source 20)

• Official position, Low certainty.
• Size: 8 of 3,007 patients in clinical trials.
• Who: patients using mometasone furoate inhalation powder.
• How long: clinical trial programme; long-term use flagged for ophthalmology referral.
• Result: glaucoma, increased intraocular pressure and cataracts in 8 of 3,007 patients (about 0.27%)
• Funding: manufacturer document (regulatory label)

glaucoma, increased intraocular pressure, and cataracts have been reported in 8 of 3007 patients following the administration of ASMANEX TWISTHALER

What the evidence supports

Mometasone ranked the most effective licensed-dose intranasal steroid for moderate-to-severe seasonal allergic rhinitis, with a modest effect against placebo. (Source 2)

• Meta-analysis, Moderate certainty.
• Size: 26 randomised trials: 13 with 5,134 seasonal and 13 with 4,393 perennial allergic rhinitis patients.
• Who: patients with moderate-to-severe allergic rhinitis.
• How long: trial durations not specified in the abstract.
• Result: seasonal AR total nasal symptom score SMD -0.47 (95% CI -0.63 to -0.31), ranked first of five; acceptability (study dropout) not inferior to placebo for any agent.
• Funding: not stated in the abstract; the review notes most placebo-controlled studies had moderate quality of evidence.

In seasonal AR, mometasone furoate (MF) was ranked the highest efficacy, followed by fluticasone furoate (FF), ciclesonide (CIC), fluticasone propionate and triamcinolone acetonide (TAA) (SMD -0.47, 95% CI: -0.63 to -0.31

Intranasal steroids as a class relieve nasal symptoms of allergic rhinitis better than non-sedating oral antihistamines. (Source 21)

• Meta-analysis, Moderate certainty.
• Size: 5 randomised controlled trials, 990 patients in the meta-analysis, plus 4 trials in a narrative analysis.
• Who: patients with allergic rhinitis.
• How long: not specified in the abstract.
• Result: total nasal symptom score SMD -0.70 (95% CI -0.93 to -0.47); nasal obstruction -0.56; sneezing -0.52; nasal itching -0.42; rhinorrhoea -0.47 (95% CI -1.00 to 0.05, crossing zero); no difference in eye symptoms (SMD -0.08, 95% CI -0.23 to 0.08)
• Funding: not stated in the abstract; GRADE-based review.

INS were superior to OAs in improving total nasal symptoms score (SMD -0.70 [95% CI, -0.93 to -0.47])

Mometasone nasal spray shrank nasal polyps and eased congestion more than placebo in a large randomised trial, but the absolute differences were small. (Source 3)

• Randomized trial, Moderate certainty.
• Size: 748 randomised (375 mometasone 200 mcg twice daily, 373 placebo)
• Who: Chinese adults with bilateral nasal polyps graded 1 to 3.
• How long: 14-day placebo run-in then 16 weeks of treatment.
• Result: nasal congestion/obstruction difference -0.14 (95% CI -0.22 to -0.06), p=0.0007; total polyp size score at week 16 -0.30 (95% CI -0.45 to -0.15), p<0.0001; serious adverse events 0.5% versus 0.8%.
• Funding: not stated in the abstract; manufacturer-style registration trial of a branded product.

The between-treatment difference in LS mean change from baseline in total polyp size score at week 16 was -0.30 (95% CI, -0.45 to -0.15) for MFNS vs placebo (p < 0.0001).

In Nordic patients with mild-to-moderate nasal polyposis, once-daily mometasone improved the investigator-rated congestion score in three-quarters of patients versus under half on placebo. (Source 22)

• Randomized trial, Moderate certainty.
• Size: 298 randomised, 291 in the intention-to-treat efficacy analysis.
• Who: adults 18 and over with bilateral nasal polyps and clinically significant nasal congestion at 12 centres in Denmark, Finland, Norway and Sweden.
• How long: 2-4 week run-in then 16 weeks.
• Result: improvement in investigator-assessed nasal congestion 74.3% versus 46.8%, p < 0.001; secondary benefits on polyp size, sense of smell and peak nasal inspiratory flow.
• Funding: not stated in the abstract; multicentre trial of a branded product.

a statistically greater proportion of the MFNS group than the placebo group had improvements in investigator-assessed nasal congestion score between baseline and end point (the primary outcome) (74.3% vs 46.8%; p < 0.001)

Pooled paediatric asthma trials found inhaled mometasone improved lung function compared with placebo without raising overall adverse events. (Source 4)

• Meta-analysis, Low certainty.
• Size: four randomised controlled trials.
• Who: children with asthma.
• How long: not specified in the abstract.
• Result: predicted FEV1 mean difference 7.53 (95% CI 7.02-8.04); FEV1 0.11 (0.10-0.12); morning peak expiratory flow 17.70 (9.91-25.49); adverse events RR 1.05 (0.84-1.31, p=0.69); upper respiratory tract infection RR 0.73 (0.50-1.05)
• Funding: not stated in the abstract; only four trials, and a separate paediatric mometasone meta-analysis was withdrawn by its publisher for repetitive publication.

Mometasone furoate may be effective and safe for paediatric asthma.

What the evidence does not support

Mometasone nasal spray was no better than placebo for glue ear in children, and the small difference favoured placebo. (Source 6)

• Randomized trial, High certainty.
• Size: 217 children randomised, 194 analysed at one month (96 steroid, 98 placebo)
• Who: children aged 4 to 11 with bilateral otitis media with effusion confirmed by otoscopy and micro-tympanometry, in 76 UK general practices.
• How long: three months of treatment, with follow-up at 1, 3 and 9 months.
• Result: cure in one or both ears at one month 39/96 (41%) versus 44/98 (45%), difference favouring placebo 4.3% (95% CI -9.3% to 18.1%); adjusted relative risk 0.97 (0.74-1.26); at three months 58% versus 52% (RR 1.23, 0.84-1.80); diary symptoms no different and no significant harms.
• Funding: Medical Research Council General Practice Research Framework (public funding, independent)

Topical steroids are unlikely to be an effective treatment for otitis media with effusion in general practice.

For perennial allergic rhinitis, mometasone ranked last of the five intranasal steroids compared, with the weakest effect estimate. (Source 2)

• Meta-analysis, Moderate certainty.
• Size: 13 trials with 4,393 perennial allergic rhinitis patients.
• Who: patients with moderate-to-severe perennial allergic rhinitis.
• How long: not specified in the abstract.
• Result: mometasone SMD -0.28 (95% CI -0.55 to -0.01), the smallest of the five and with a confidence interval almost touching zero, versus budesonide -0.43 ranked first.
• Funding: not stated in the abstract.

In perennial AR, budesonide was ranked the highest efficacy, followed by FF, TAA, CIC, and MF

In children, mometasone nasal spray at clinically relevant doses did not slow short-term lower-leg growth. (Source 23)

• Randomized trial, Low certainty.
• Size: 22 children aged 7 to 12, randomised double-blind crossover.
• Who: children with seasonal or perennial allergic rhinitis.
• How long: 2 weeks per treatment period with 2-week washouts.
• Result: lower-leg growth 0.95 mm on mometasone 200 mcg, 0.73 mm on budesonide 400 mcg and 0.69 mm on placebo, no significant differences; overall treatment effect p = 0.086. This is a null result for harm, over only two weeks in 22 children.
• Funding: not stated in the abstract; knemometry study of a branded product.

No short-term adverse effects on linear lower leg growth rates were detected after once daily MF or budesonide at clinically relevant doses.

Topical 0.1% mometasone ointment did not slow short-term lower-leg growth in children with mild to moderate eczema. (Source 5)

• Randomized trial, Very low certainty.
• Size: 20 prepubertal children aged 5 to 12.
• Who: children with atopic eczema.
• How long: five 2-week periods in a randomised investigator-blind crossover design.
• Result: lower-leg growth rate fell by 0.09 mm/week on mometasone and 0.06 mm/week on tacrolimus versus run-in (F = 1.12, p = 0.35); no significant change in urinary eosinophil protein X or cross-linked N-telopeptides.
• Funding: not stated in the abstract; 20 children is a very small sample for a safety endpoint.

Treatment with mometasone furoate or tacrolimus does not affect short-term growth in children with mild to moderate atopic eczema.

Where the evidence is mixed

The congestion benefit in the largest nasal polyp trial was a fraction of a point on the symptom scale, so statistical significance does not translate into a large clinical change. (Source 3)

• Randomized trial, Moderate certainty.
• Size: 748 randomised.
• Who: Chinese adults with bilateral nasal polyps.
• How long: first 4 weeks of treatment for this endpoint.
• Result: least-squares mean difference in nasal congestion/obstruction -0.14 (95% CI -0.22 to -0.06), p = 0.0007 on a categorical symptom score.
• Funding: not stated in the abstract.

The between-treatment difference in least squares (LS) mean change from baseline in nasal congestion/obstruction over 4 weeks of treatment was -0.14 (95% confidence interval [CI], -0.22 to -0.06) for MFNS vs placebo (p = 0.0007).

For adenoid hypertrophy, the randomised evidence compares mometasone against mometasone plus montelukast rather than against placebo, and no trial assessed montelukast's known neuropsychiatric harms. (Source 7)

• Meta-analysis, Low certainty.
• Size: 5 randomised trials, 416 children under 15.
• Who: children with clinically diagnosed adenoid hypertrophy.
• How long: not specified in the abstract.
• Result: combination therapy beat mometasone alone on adenoid/nasopharynx ratio (-7.01, 95% CI -8.96 to -5.07) and total symptom score (-1.05, -1.51 to -0.59) but not on nasal obstruction (-0.06, -0.26 to 0.14) or snoring (-0.56, -1.19 to 0.08); safety data including montelukast neuropsychiatric effects were not reported in any included study.
• Funding: not stated in the abstract.

Although safety data, including neuropsychiatric adverse effects of montelukast, were of interest, they were not reported in the included studies.

Where the research disagrees

Whether mometasone is the best intranasal steroid for allergic rhinitis

• Sangsawang and colleagues, network meta-analysis of licensed-dose intranasal steroids (2023), network meta-analysis of 26 randomised trials, 9,527 patients, mostly moderate quality for placebo comparisons: In seasonal AR, mometasone furoate (MF) was ranked the highest efficacy (Source 2)
• The same network meta-analysis, for perennial disease, same network meta-analysis, 13 trials with 4,393 perennial allergic rhinitis patients - ranking reversed by rhinitis type, which the authors note rests on indirect comparison: In perennial AR, budesonide was ranked the highest efficacy, followed by FF, TAA, CIC, and MF (Source 2)

Whether inhaled mometasone affects children's growth

• Skoner and colleagues, 52-week placebo-controlled growth trial (2011), randomised placebo-controlled trial, 187 children aged 4 to 9, 52 weeks, stadiometry: The differences in growth velocity, and the absence of drug-related cortisol effects, support the use of a total daily dose of 100 (Source 17)
• Loke and colleagues, inhaled corticosteroid growth meta-analysis (2015), systematic review and meta-analysis of 23 studies; class-level, not mometasone-specific: Use of ICS for >12 months in children with asthma has a limited impact on annual growth velocity. In ICS users, there is a slight reduction of about a centimeter in final adult height (Source 18)

How much

• Reference intake: There is no reference intake for a drug. As a position, the 2026 US mometasone furoate nasal spray label states 2 sprays (100 mcg total) in each nostril once daily, a total daily dose of 200 mcg, for seasonal allergic rhinitis in people 12 and over. (Source 24)
• Upper limit: No toxicological upper limit exists. As a position, the highest labelled nasal dose is 2 sprays in each nostril twice daily, a total daily dose of 400 mcg, for chronic rhinosinusitis with nasal polyps in adults 18 and over. For the inhaler, the label's own growth and bone data show the systemic cost rises with dose rather than at a defined threshold. (Source 24)
• Studied: The negative glue ear trial gave mometasone furoate 50 mcg or placebo spray once daily into each nostril for three months. (Source 6)
• Studied: The 748-patient nasal polyp trial used mometasone furoate nasal spray 200 mcg twice daily for 16 weeks. (Source 3)
• Studied: The Nordic nasal polyp trial used 200 mcg once daily in the morning for 16 weeks. (Source 22)
• Studied: The paediatric growth and adrenal trial randomised children aged 4 to 9 to mometasone dry powder inhaler 100 mcg once daily, 100 mcg twice daily, 200 mcg once daily or placebo for 52 weeks. (Source 17)
• Studied: The eczema knemometry study applied mometasone furoate ointment 0.1% once daily for two weeks. (Source 5)

A common belief, and what the research shows

The belief: A steroid nasal spray is a harmless local treatment, so it is fine to use indefinitely and fine for anything that blocks a child's ears or nose.

What the research shows: It is local, but not inert and not a general ear-and-nose remedy. In children with glue ear a randomised trial found "Topical steroids are unlikely to be an effective treatment for otitis media with effusion in general practice." Nosebleeds are real and measured: in the trial programme epistaxis ran "9% for 200 mcg once daily, 13% for 200 mcg twice daily, and 5% for the placebo." and across 72 trials the pooled estimate was "an overall relative risk of epistaxis of 1.48 (95% CI, 1.32-1.67) for all INCSs." The label also records that "Instances of nasal septum perforation occurred in patients following the nasal application of corticosteroids, including mometasone furoate nasal spray." and that "Corticosteroids, including mometasone furoate nasal spray may cause a reduction in growth velocity when administered to pediatric patients."

Questions and answers

What is it?

Mometasone furoate is a man-made corticosteroid made to work hard where it lands and then be cleared fast. It comes as a nasal spray, as a dry-powder or aerosol inhaler for asthma, and as a 0.1% cream, ointment or lotion for the skin. The liver enzyme CYP3A4 does most of the breaking down. (Source 1)

What does it do in the body?

It binds the glucocorticoid receptor in the cells of the nasal lining, airway or skin and switches off the genes driving inflammation, so swelling, mucus, itch and redness fall. Because absorption is low and clearance fast, whole-body steroid effects are less likely than with tablets, but at higher doses, over large skin areas or in small children they do occur. (Source 1)

Is it good or bad for you?

Good for the conditions where it has been tested properly - allergic rhinitis, nasal polyps, asthma, inflamed skin - and the effect sizes are modest rather than dramatic. Not good for glue ear, where a randomised trial found it no better than placebo. The harms that are documented with numbers are nosebleeds (about 11% versus 6%), nasal septum perforation, and systemic effects at higher exposure: slowed growth velocity in children, reduced lumbar spine bone density over two years, and adrenal suppression in about 16% of infants treated over a large skin area. (Source 14)

How do you get more of it?

Mometasone is a manufactured drug with no dietary source. The amount is set by the product and the label, and in the US the nasal spray is available over the counter as well as on prescription. As a position, the label describes 2 sprays per nostril once daily, 200 mcg total, for seasonal allergic rhinitis, rising to twice daily, 400 mcg total, for nasal polyps in adults. (Source 24)

If it is harmful, what reduces it?

If there is too much systemic steroid effect, the documented route back is to withdraw the drug gradually, use it less often, or switch to a weaker steroid; after topical use the adrenal axis usually recovers quickly. There is no antidote and nothing that speeds clearance. For children, the over-the-counter nasal spray label limits duration rather than dose, advising a doctor be involved beyond two months a year. (Source 10)

Why might someone be low in it or missing it?

There is no deficiency state - mometasone is a drug, not a nutrient. Exposure can be lower or higher than intended: a strong CYP3A4 inhibitor such as long-term ketoconazole or ritonavir raises it, and poor spray technique or a blocked nose lowers how much reaches the target tissue. With the cream, how much gets into the bloodstream depends on potency, surface area, duration, occlusion and the person's age. (Source 10)

Which whole foods contain it or feed it?

No whole food contains mometasone and none is known to feed or raise it. The only food-related consideration we found is theoretical: grapefruit inhibits the CYP3A4 enzyme that clears mometasone, so it could in principle raise systemic exposure, but no study has measured this and the label states that no formal drug interaction studies were done. (Source 1)

What happens if you do not have it?

Nobody needs mometasone to be healthy. If it is withheld where it helps, the trial evidence implies allergic rhinitis symptoms about half a standard deviation worse than on treatment, less polyp shrinkage and poorer asthma lung function. If it is withheld for glue ear, the evidence says nothing is lost: cure rates were 41% on drug and 45% on placebo at one month. (Source 6)

How can you test for it?

There is no routine test for a mometasone level. What gets tested is its systemic footprint: an ACTH stimulation test for suppression of the body's own cortisol, serum or 12-hour urinary cortisol in the trials, and in children stadiometry to track growth velocity. The labels ask for routine growth monitoring in children rather than a blood test. (Source 25)

References

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8. Organon LLC (US FDA label via DailyMed). ASMANEX TWISTHALER (mometasone furoate inhalation powder) - US prescribing information - Warnings and Precautions 5.6 Hypercorticism and Adrenal Suppression. 2026. Read the source
9. Organon LLC (US FDA label via DailyMed). ASMANEX TWISTHALER (mometasone furoate inhalation powder) - US prescribing information - Drug Interactions, Strong CYP3A4 Inhibitors. 2026. Read the source
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14. Apotex Corp. (US FDA label via DailyMed). Mometasone Furoate Nasal Spray 50 mcg - US prescribing information - Warnings and Precautions 5.1 Local Nasal Adverse Reactions. 2026. Read the source
15. Preferred Pharmaceuticals Inc. (US FDA label via DailyMed). Mometasone Furoate Cream USP 0.1% - US prescribing information - Use in Specific Populations 8.4 Pediatric Use. 2026. Read the source
16. Preferred Pharmaceuticals Inc. (US FDA label via DailyMed). Mometasone Furoate Cream USP 0.1% - US prescribing information - Adverse Reactions. 2026. Read the source
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20. Organon LLC (US FDA label via DailyMed). ASMANEX TWISTHALER (mometasone furoate inhalation powder) - US prescribing information - Warnings and Precautions 5.9 Glaucoma and Cataracts. 2026. Read the source
21. American journal of rhinology & allergy. Intranasal corticosteroids compared with oral antihistamines in allergic rhinitis: A systematic review and meta-analysis. 2017. PMID 28234147, DOI 10.2500/ajra.2016.30.4397. Read the source
22. Acta oto-laryngologica. The efficacy and safety of once-daily mometasone furoate nasal spray in nasal polyposis: a randomized, double-blind, placebo-controlled study. 2006. PMID 16720445, DOI 10.1080/00016480500452566. Read the source
23. The Journal of allergy and clinical immunology. Short-term lower leg growth rate in children with rhinitis treated with intranasal mometasone furoate and budesonide. 1999. PMID 10550737, DOI 10.1016/s0091-6749(99)70073-4. Read the source
24. Apotex Corp. (US FDA label via DailyMed). Mometasone Furoate Nasal Spray 50 mcg - US prescribing information - Dosage and Administration. 2026. Read the source
25. Apotex Corp. (US FDA label via DailyMed). Mometasone Furoate Nasal Spray 50 mcg - US prescribing information - Precautions, Effects on Growth. 2026. Read the source