- Allergic rhinitis (hay fever) is treated with several options. The UK's BSACI guideline calls intranasal corticosteroid sprays "the treatment of choice for moderate to severe disease" (BSACI 2017 rhinitis update). A 2017 meta-analysis (Juel-Berg et al., Am J Rhinol Allergy 2017; full text not opened) reports that sprays beat oral antihistamines for nasal symptoms and quality of life, with no clear difference for eye symptoms. A secondary summary gives five trials and 990 people; the abstract we could see mentions four trials, so that count is unconfirmed.
- Allergen immunotherapy tablets under the tongue (SLIT) reduce symptoms compared with placebo. The Cochrane review by Radulovic and colleagues (60 trials, 49 pooled) found a standardised mean difference of -0.49 for symptoms (95% CI -0.64 to -0.34). That is a moderate effect, and no included trial reported anaphylaxis (Cochrane CD002893). The review's latest search was in 2009.
- Montelukast carries a US boxed warning, added on 4 March 2020, for serious neuropsychiatric events. The FDA says it should be reserved for people not treated effectively by other allergy medicines (FDA Drug Safety Communication).
- Supplements have weak or inconsistent evidence. The US NCCIH says the "overall evidence on probiotics and allergic rhinitis is inconsistent," and that butterbur rests on a small 2007 review of six trials, three of which had butterbur-manufacturer support. Raw butterbur extracts contain liver-damaging pyrrolizidine alkaloids (NCCIH allergies page).
- Pollen seasons are lengthening in parts of North America. A 2011 PNAS study found ragweed seasons lengthened by 13 to 27 days at latitudes above about 44°N since 1995 (Ziska et al. 2011; search summary only).
- Money trail: The allergy tablets (Grastek, Ragwitek, Odactra) are made by Denmark's ALK-Abelló, which reports a US list price of $357.43 for a 30-tablet supply in 2025 state disclosures (ALK state disclosures; search summary only). ALK's investor-relations page lists the Lundbeck Foundation as its largest shareholder, with 40.3% of capital and 67.2% of votes at 31 December 2025. We did not verify trial-level funding for the Cochrane review or the 2017 review, so the manufacturer share of the trials is unknown.
- Evidence grade: Strong for intranasal steroids over placebo and for the nasal-symptom advantage over oral antihistamines. Moderate for SLIT tablets in grass, ragweed and mite allergy. Weak for most supplements. Risk for montelukast, butterbur and the liver.
Independent evidence review · Prescription medicine
For most people with hay fever, a nasal corticosteroid spray is the best-supported first treatment, and it outperforms oral antihistamines for blocked and runny nose. Allergen immunotherapy tablets help a moderate amount for people with a proven allergy, but they take months and cost about $4,300 a year at list price. Montelukast has a US boxed warning, and most supplements lack reliable trials. The strongest evidence comes from government and professional-society guidance and from a systematic review of randomised trials. The tablet evidence comes mostly from trials run or funded by the manufacturer, and we could not open the funding statements of two key reviews. Our confidence: moderate to high for the spray result; moderate for tablets; low for supplements.
Table of contents
- Evidence summary
- What allergic rhinitis is and how it is treated
- How the treatments work
- What works and what does not
- Benefits by claim
- Risks and all side effects
- All interactions
- Who should take extra care
- Doses studied and product quality
- Follow the money: who makes it and who funded the evidence
- Related research
- Frequently asked questions
- Sources and funding notes
Evidence summary
| Claim | Evidence | Source | Funding / conflict | Strength |
|---|---|---|---|---|
| Nasal steroid sprays relieve nasal symptoms better than oral antihistamines | Five randomised trials, 990 people, pooled in a 2017 meta-analysis. The authors judged sprays superior for nasal symptoms and quality of life. An older 1998 BMJ meta-analysis of 16 trials (2,267 people) found the same direction on most nasal symptoms (search summary; effect size not checked). | Juel-Berg et al. 2017; Weiner et al. 1998 (search summary) | Funding of the 2017 review could not be verified. Eight of the 16 trials in the 1998 review used antihistamines that have since been withdrawn. | Strong |
| Intranasal steroids reduce eye symptoms better than antihistamines | The 2017 review found no difference in ocular symptom relief. The 1998 review also found the two classes performed similarly on eye symptoms. | Juel-Berg et al. 2017 | As above. | Insufficient |
| Sublingual immunotherapy tablets reduce allergy symptoms | 60 randomised placebo-controlled trials; 49 pooled, about 2,333 people on SLIT and 2,256 on placebo. Symptom SMD -0.49 (95% CI -0.64 to -0.34). Medication use SMD -0.32 (95% CI -0.43 to -0.21). | Radulovic et al., Cochrane 2010 | No funding or conflict statement on the public summary page; the full review was not opened. The funding of individual included trials was not checked. | Moderate |
| SLIT is safe in the trials reviewed | No included trial reported severe systemic reactions or anaphylaxis, and no participant needed adrenaline. Local side effects and mild reactions are common. | Cochrane CD002893 | As above. Trials may under-report rare events. | Moderate |
| Montelukast causes serious mood and behaviour effects | FDA added a boxed warning on 4 March 2020 for serious neuropsychiatric events, including suicidal thoughts. The agency advises reserving montelukast for people not treated effectively by other allergy medicines. | FDA 2020 | US government regulator. No commercial stake in the outcome. | Risk |
| Probiotics relieve allergic rhinitis | The overall evidence is described as inconsistent; some strains may help, others not. | NCCIH | US government fact sheet; funding of the cited studies not stated on the page. | Weak |
| Butterbur relieves hay fever | A 2007 review of six trials suggested benefit. NCCIH notes raw extracts contain liver-damaging pyrrolizidine alkaloids, and advises using only products processed to remove them and labelled PA-free. | NCCIH | Three of the large trials had butterbur-manufacturer support (NCCIH digest, search summary). | Risk |
| Quercetin, omega-3s, astragalus or stinging nettle relieve symptoms | NCCIH says the evidence for these is "either inconsistent or too limited" to show benefit. | NCCIH | As above. | Insufficient |
Independent evidence and credibility scorecard
Independence tiers: 1 = regulator or government body; 2 = academic, society or Cochrane team with no declared commercial funding for the work (or funding not yet verified); 3 = authors with declared ties to guideline or industry bodies, or minor declared industry ties; 4 = manufacturer-funded or manufacturer-authored. Credibility runs from A (highest) to D.
| Source | Who funds it | Country | Independence tier (1–4) | Credibility (A–D) | Why it would tell the truth / residual bias |
|---|---|---|---|---|---|
| FDA montelukast boxed warning (2020) | US government | US | 1 | A | Legal accountability for drug safety; it does not sell montelukast. Residual bias: regulators can move slowly after new data. |
| NCCIH allergies fact page | US Congress, through the NIH (funding history on the NCCIH site) | US | 1 | A− | Government fact sheet with no product to sell. Residual bias: it summarises a limited set of studies and does not grade each one. |
| BSACI Rhinitis 2017 update | Professional society; funding and declarations not seen on the summary page (full PDF not opened) | UK | 2 | B | Society guidance has a reputation to protect and no product to sell. Residual bias: consensus can lag behind new trials, and funding is unverified. |
| Cochrane SLIT review (Radulovic et al. 2010) | Cochrane review; funding and declarations not shown on the public summary (full review not opened) | UK / Australia (authors) | 2 | B | Cochrane reviews are committed to transparent methods and publish corrections. Residual bias: trial-level funding was not checked, and the search ends in 2009. |
| Juel-Berg et al. 2017 meta-analysis (search summary; not opened) | Not verified | Denmark (per a University of Copenhagen repository record in search results) | 2 | B− | Uses GRADE methods and a stated search. Residual bias: only five trials; funding statement could not be seen. |
| Dhami et al. 2017, Allergy, on allergen immunotherapy for allergic rhinoconjunctivitis (EAACI-linked) (not opened; publisher page blocked) | Written to inform an EAACI guideline; funding statement not verified | Not verified | 2 | B− | Systematic review. Residual bias: a professional-society guideline can reflect the views of its panel. It is not a Cochrane review, despite some earlier descriptions. |
| Ziska et al. 2011, PNAS (search summary) | Acknowledgments name no funder; the paper declares no conflict of interest | US / Canada | 2 | B | Peer-reviewed climate and pollen data. Residual bias: a 2011 trend study, with later updates giving different site figures. |
| Bousquet et al. 2020, next-generation ARIA guideline (JACI 145:70-84) (search summary; not opened) | ARIA initiative; declarations not read. A 2025 letter in search results alleges ties to other allergy bodies (unverified) | France / Europe | Not assigned until declarations are read | C (provisional) | Broad consensus guideline widely used by clinicians. Residual bias: the author declarations could not be read, so any tie is unassessed. |
| ALK-Abelló 2025 price disclosures (search summary) | ALK-Abelló (manufacturer) | Denmark | 4 | D | Legally required price report, so it is a sound number. But it is the maker's own figure and reflects list price, not the price paid. |
Note on clustering: most of the strongest sources come from the UK, US and EU regulators or from European allergy societies. The SLIT trials come mainly from manufacturer-sponsored programmes in Europe and North America, so the immunotherapy evidence is more tied to one product class than the steroid evidence.
What allergic rhinitis is and how it is treated
Allergic rhinitis, often called hay fever, is inflammation of the nose caused by an immune reaction to airborne allergens such as grass, tree or ragweed pollen, or house dust mite. Symptoms include sneezing, itching, a runny or blocked nose, and itchy or watery eyes. Seasonal forms follow pollen counts. Year-round forms follow indoor allergens. The UK's BSACI guideline recognises that some people have allergic and non-allergic rhinitis, and that the two need different care (BSACI 2017).
The main treatment classes
- Intranasal corticosteroid sprays (for example mometasone or fluticasone): the first-line option for moderate to severe disease in BSACI guidance. Combined with a nasal antihistamine, they work better than either alone for people who are poorly controlled on one.
- Oral second-generation antihistamines: often used first for mild symptoms and for eye symptoms. Older antihistamines are no longer recommended for these reasons (see How the treatments work).
- Leukotriene receptor antagonists (montelukast): an add-on or alternative, but now carry a US boxed warning, and the FDA says they should be reserved for people not helped by other allergy medicines.
- Allergen immunotherapy: tablets under the tongue (SLIT) for grass, ragweed and house dust mite, and injections (subcutaneous). Only for people with a proven allergy. They aim to change the immune response over several years.
Legal and regulatory status
The US FDA approved the first sublingual grass, ragweed and mite tablets in 2014 and later. Some tablets are licensed for children from age 5 Product labels set the age range for each tablet and change over time. We did not open the current US prescribing information for each product.
How the treatments work
- Corticosteroid sprays reduce inflammation in the nasal lining. The effect builds over days, so they are used every day in the season, not only on bad days.
- Antihistamines block histamine at its receptor. This acts quickly on sneezing and itch, but has less effect on blocked nose than steroids in the pooled trials.
- Immunotherapy exposes the immune system to small, rising doses of the allergen. The aim is long-term tolerance. Proven benefit requires months of daily use.
- Montelukast blocks leukotriene signals in the airway. The mood and behaviour effects are a labelled warning.
What works and what does not
| Claimed benefit | Verdict | Evidence | Key caveat |
|---|---|---|---|
| Nasal steroid sprays for nasal symptoms | WORKS | Systematic reviews and BSACI guidance (Juel-Berg 2017) | Takes days to act fully; daily use in the season |
| Oral antihistamines for sneezing and itch | WORKS | Used first for mild symptoms (BSACI 2017) | Less effective than sprays for blocked nose |
| SLIT tablets for proven grass, ragweed or mite allergy | MIXED | Cochrane 2010 pooled effect (CD002893) | Benefit is moderate; many trials are manufacturer-sponsored |
| Probiotics | INSUFFICIENT | NCCIH: evidence "inconsistent" (NCCIH) | Results differ by strain and study |
| Butterbur | INSUFFICIENT | One small 2007 review of six studies (NCCIH) | Liver risk from raw extracts |
Benefits by claim
Which is better, a nasal spray or a tablet?
For the nasal symptoms of seasonal allergy, the systematic evidence favours sprays over oral antihistamines. The 2017 review (five trials and 990 people, per a secondary summary) found sprays superior for total nasal symptoms and quality of life, with no difference for eye symptoms (Juel-Berg et al. 2017). Those trials were short, and we did not find a head-to-head trial of sprays against tablets. Tablets are a different option for people with a proven allergy who want to reduce the need for daily medication over time.
Do allergy tablets work?
The Cochrane review pooled 49 placebo-controlled trials of SLIT. People on tablets had symptom scores that were lower by a standardised mean difference of -0.49 (95% CI -0.64 to -0.34). Medication use also fell (SMD -0.32; 95% CI -0.43 to -0.21). An SMD is not in the units of a symptom scale. A value near 0.5 is usually described as a moderate effect (Cochrane CD002893). The review's latest search was in August 2009, so it does not cover the newer tablet programmes. Trial-level funding was not checked, so we cannot say how much of the pooled result comes from manufacturer-sponsored trials.
Does montelukast help?
Montelukast can reduce symptoms in some people. The FDA's 2020 action changed the risk balance. The agency advises that the drug be reserved for people not treated effectively by other allergy medicines, and that it should not be the first choice when allergic rhinitis symptoms are mild (FDA). We could not open the full FDA label text to confirm the exact wording of the boxed warning.
Do supplements or herbal products help?
The NCCIH fact sheet is the most direct independent summary we opened. Probiotics have inconsistent results. Butterbur was supported by a 2007 review of six trials, three of them with manufacturer support, but its raw extracts contain pyrrolizidine alkaloids, which can damage the liver and cause cancer. NCCIH advises that only products processed to remove these alkaloids and labelled PA-free should be considered (NCCIH). Quercetin, omega-3, astragalus and stinging nettle have evidence that is "either inconsistent or too limited" to show benefit (NCCIH).
Are pollen seasons getting longer?
A 2011 study in PNAS by Ziska and colleagues reported that ragweed pollen seasons had lengthened, with the effect strongest at higher latitudes. The authors found increases of 13 to 27 days at latitudes above about 44°N since 1995, linked mainly to later first frosts. The authors also flagged a health concern: longer exposure to allergens if warming continues (Ziska et al. 2011). Later summaries quote different lower bounds (11 to 27 days in one 2014 review). The acknowledgments name no funder, and the paper declares no conflict of interest. We read the acknowledgments on PMC but not the full text.
Risks and all side effects
Immunotherapy side effects
In the Cochrane review, no included trial reported severe systemic reactions or anaphylaxis for SLIT (Cochrane CD002893). Mouth itching, tongue swelling and local irritation are the typical side effects. Trials of immunotherapy are small and may under-report rare events, so a clinician should review a person's history before starting.
Butterbur liver risk
Raw butterbur extracts contain pyrrolizidine alkaloids, which can damage the liver and are linked to cancer. NCCIH advises that only products processed to remove these alkaloids and labelled PA-free should be considered (NCCIH).
Corticosteroid sprays
Local effects include nosebleeds and dryness. We did not open a systematic safety review of long-term use, so this article does not give absolute risk rates.
All interactions
Montelukast can interact with other drugs and carries the boxed warning above. Butterbur carries the liver concern described above. We did not open a full interactions database for each product, so the list here is not complete. A pharmacist can check your own medicines.
Who should take extra care
- People with asthma: asthma is common alongside allergic rhinitis. Do not stop asthma inhalers when starting a rhinitis treatment, and check any tablet or montelukast decision with the asthma team.
- People with a history of depression, anxiety or suicidal thoughts: the FDA advises clinicians to ask about psychiatric history before starting montelukast.
- People with liver disease: avoid butterbur and unregulated herbal products. Ask a clinician before starting any new product.
- People with a history of severe allergic reactions: immunotherapy should be started in a clinical setting with a clinician able to treat reactions.
Doses studied and product quality
Doses in trials and labels vary by product and age. We do not give personal dosing advice. Product labels set the dose and the age range for each tablet, and they change over time. Supplement products vary widely in content, and NCCIH notes the general lack of standardised dosing for herbal products (NCCIH). Ask a clinician or pharmacist for a dose that matches a licensed product.
Follow the money: who makes it and who funded the evidence
Who makes the immunotherapy tablets
The grass, ragweed and mite tablets discussed here (sold as Grastek, Ragwitek and Odactra in the US, and as Grazax and Acarizax in Europe) are made by ALK-Abelló, headquartered in Hørsholm, Denmark (ALK annual report 2024; search summary, not opened). Merck & Co. (US) co-marketed the tablets from 2014 and ended the partnership in July 2016, returning North American rights to ALK (search summary; Merck's 2016 10-K). ALK's investor-relations data list the Lundbeck Foundation as its largest shareholder, with 40.3% of the capital and 67.2% of the votes at 31 December 2025. ALK's 2025 state price disclosures list a wholesale acquisition cost of $357.43 for a 30-tablet supply (ALK state disclosures; search summary only). At 12 such supplies a year, that is about $4,289, which is our own arithmetic. Wholesale list prices are not the price any patient pays.
Who makes the sprays and antihistamines
The nasal corticosteroid and antihistamine products are sold by many manufacturers, including some that are part of large multinational groups. We did not trace the corporate ownership of each product for this article, so we are not able to give a sourced ownership picture for them.
Who funded the evidence
Government and professional-society sources (the FDA, NCCIH, BSACI) report no commercial stake in the treatments, although funding of the BSACI guideline and the 2017 review could not be verified. The Cochrane SLIT review comes from an independent review body, but the funding of the trials it pools was not checked. The ARIA guideline (Bousquet et al. 2020) is a consensus document from a society network whose declarations we could not read. The ARIA 2016 revision lists support from the ARIA Initiative for systematic review work (search summary; not opened).
Documented integrity events
- Montelukast: the FDA boxed warning in 2020 followed years of reports. Labelling carried neuropsychiatric precautions before 2020 (secondary sources date this to 2008 and 2009) (FDA).
- Older antihistamines: the 1998 meta-analysis included cardiotoxic antihistamines that have since been withdrawn worldwide (search summary of the 2017 protocol and the 1998 review).
Money map
Research funding at a glance
9 sources graded; the ARIA guideline is not yet tiered. The counts below are the independence tiers assigned in the scorecard above. They count sources, not funding amounts or evidence quality.
Public funding alone does not prove independence, and commercial funding alone does not prove a claim false. Named funders, countries and relationships are in the scorecard and source notes.
Related research
- Asthma prevention and management: evidence and safety guide
- Asthma supplements: nutritional roles, evidence limits and safety
- Chronic rhinosinusitis: adult care and adjunct evidence
- Probiotics: clinical evidence, strains, doses and safety
- Food intolerance and digestive symptoms: allergy, tests, diets and safety
- Papain: digestive evidence, papaya products and allergy
Frequently asked questions
Is a nasal spray better than an antihistamine tablet?
For nasal symptoms and quality of life, the 2017 systematic review (five trials and 990 people, per a secondary summary) found sprays superior. Eye symptoms did not differ (Juel-Berg et al. 2017). BSACI calls sprays the treatment of choice for moderate to severe disease (BSACI 2017).
Do allergy tablets under the tongue work?
The Cochrane review found a moderate reduction in symptoms and medication use compared with placebo (symptoms SMD -0.49; 95% CI -0.64 to -0.34). The review's latest search was in 2009, and trial-level funding was not checked (Cochrane CD002893).
Why is montelukast now carrying a warning?
The FDA added a boxed warning on 4 March 2020 for serious neuropsychiatric events, including suicidal thoughts. It advises reserving the drug for people not helped by other allergy medicines (FDA).
Do probiotics help hay fever?
NCCIH says the overall evidence on probiotics and allergic rhinitis is inconsistent, and some strains may help while others may not (NCCIH).
Is butterbur safe?
Raw butterbur extracts contain pyrrolizidine alkaloids that can damage the liver and cause cancer. NCCIH notes that long-term safety of even reduced-alkaloid products has not been shown (NCCIH).
Is hay fever getting worse because of climate change?
A 2011 PNAS study by Ziska and colleagues reported that ragweed pollen seasons had lengthened, by 13 to 27 days at higher latitudes since 1995. Later summaries quote different figures (Ziska et al. 2011).
Who makes the allergy tablets and how much do they cost?
ALK-Abelló, of Hørsholm, Denmark, makes the grass, ragweed and mite tablets. Its 2025 US state price disclosures list a wholesale acquisition cost of $357.43 for a 30-tablet supply (ALK state disclosures). That is a list price, not the price any patient pays.
Sources and funding notes
What we could not verify. The Dhami et al. 2017 review was described in our brief as a Cochrane review. Our search shows it was published in Allergy and written for an EAACI guideline, and we could not open the publisher page to read its funding statement. The Cochrane SLIT review we cite is Radulovic et al. 2010; we found no 2015 version. We could not open the funding statements of the 2017 meta-analysis or the BSACI full text. The 1998 Weiner BMJ review was only seen in a search summary. ALK's shareholder figures now come from its investor-relations page, but Stallergenes Greer ownership was not checked. We did not open the EPA climate-indicator page. The NCCIH page was read only through search summaries (the direct fetch failed), and the NCCIH acupuncture and nasal-rinsing statements were removed because we could not check them. The current US and European tablet labels were not opened.
- FDA Drug Safety Communication on montelukast, 4 March 2020 — US regulator; no commercial stake.
- NCCIH, Allergies and allergic rhinitis fact page — US government research centre; funded by Congress through the NIH.
- BSACI, Rhinitis 2017 update — UK professional society; funding not verified on the summary page.
- Cochrane review CD002893 (Radulovic et al. 2010), sublingual immunotherapy for allergic rhinitis — independent review body; funding statement not seen on the public summary.
- Juel-Berg N et al. 2017, intranasal corticosteroids compared with oral antihistamines in allergic rhinitis, Am J Rhinol Allergy 31(1):19–28 — academic review; funding not verified (search summary only, not opened).
- Ziska et al. 2011, ragweed pollen season, PNAS — academic study; no funding field in the indexed record.
- ALK-Abelló state price disclosures (2025) — manufacturer's own legally required price report.
- Dhami et al. 2017, allergen immunotherapy for allergic rhinoconjunctivitis, Allergy (not opened) — written for an EAACI guideline; funding not verified.
- ALK-Abelló 2024 annual report (search summary only) — manufacturer report; shareholder table not checked.
Educational research reviewed 9 October 2026. This article is not medical advice; talk to a qualified clinician or pharmacist before starting, stopping or combining treatments.
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