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Allergy · UK

Sublingual immunotherapy (SLIT) - a real fix for hay fever and dust mite.

For older children and adults with hay fever or house-dust-mite allergy that antihistamines are not controlling. A consultant allergist, a 3-year course of licensed sublingual tablets, and a plan built around exam season and asthma control.

A stethoscope on a clinical desk

Indicative pricing

What private sublingual immunotherapy costs in the UK.

In short

SLIT course: £900–£1,800 per year, for 3 years.

ItemIndicative range
Allergy consultation and workup£250–£450
Grass pollen SLIT (Grazax, per year)£900–£1,400
House-dust-mite SLIT (Acarizax, per year)£1,100–£1,600
Birch pollen SLIT (Itulazax, per year)£1,200–£1,800
Full 3-year SLIT course (typical)£2,700–£5,400
Subcutaneous immunotherapy (SCIT) per year£1,500–£3,000
Follow-up review£150–£280

The problem

A licensed disease-modifying treatment, prescribed and monitored properly.

  • A licensed, evidence-based option

    Grazax, Acarizax and Itulazax are licensed by the MHRA and used across UK specialist centres.

  • Prescribed and monitored properly

    First dose in clinic, structured follow-up, clear missed-dose and travel plans.

  • Honest on the commitment

    A SLIT course is 3 years. We say up front whether that fits your situation.

When it helps

When sublingual immunotherapy is the right step.

  • Moderate-to-severe hay fever

    Symptoms limiting sleep, school, work or exam performance despite antihistamines and nasal steroids.

  • House-dust-mite allergy with year-round symptoms

    Perennial rhinitis, poor sleep, worsening asthma.

  • Allergic asthma driven by grass, birch or mite

    Confirmed sensitisation as a real driver of asthma control.

  • Teenagers heading into GCSEs or A-levels

    Start SLIT 4 months before pollen season for the first summer of benefit.

  • Adults who have plateaued on standard treatment

    Combination antihistamines and nasal steroids no longer enough.

  • Not for peanut or tree nut allergy

    That is oral immunotherapy - a different pathway (Palforzia and specialist OIT).

  • Not for children under 5

    Licensing and evidence do not support it below school age.

  • Red flag: severe uncontrolled asthma

    SLIT is not started in severely uncontrolled asthma - that needs stabilising first.

Options

The right immunotherapy depends on the allergen and the age.

  • Grass pollen SLIT (Grazax)

    Licensed for grass pollen hay fever from age 5 upwards.

  • House-dust-mite SLIT (Acarizax)

    Licensed for adults with HDM-driven rhinitis and asthma.

  • Birch pollen SLIT (Itulazax)

    For early-spring tree-pollen hay fever.

  • Ragweed SLIT tablet

    Rarely needed in the UK; useful for travellers.

  • SLIT drops (unlicensed named-patient)

    For allergens without a licensed tablet - cat, dog, mould in selected cases.

  • Subcutaneous immunotherapy (SCIT)

    Weekly then monthly injections - used when SLIT is not suitable.

  • Venom immunotherapy

    For bee or wasp anaphylaxis - a separate specialist pathway.

  • Combined SLIT + biologic

    Selected asthma patients on omalizumab or dupilumab.

Safety and recovery

What to expect - honestly.

  • First dose in clinic

    The first dose of a SLIT tablet is given under supervision to check tolerance.

  • Local mouth and throat itching

    Common in the first weeks - usually settles.

  • Systemic reactions are rare

    Anaphylaxis on SLIT is uncommon compared with SCIT.

  • Asthma control comes first

    Uncontrolled asthma must be treated before starting SLIT.

  • Missed doses matter

    More than a week off usually means restarting under supervision.

  • Pregnancy

    SLIT is not started in pregnancy, but can be continued if already tolerated.

  • Dental work and mouth ulcers

    Pause the tablet for a few days around procedures or open ulcers.

  • Adrenaline pen on hand

    Some patients are asked to carry adrenaline during the induction period.

  • Red flag: airway swelling, breathlessness or collapse

    Adrenaline first, 999 second. Every family with a diagnosed allergy needs to be clear on this.

Your notes

Your report in four parts.

A UK consultant reviewing notes
  1. Header

    Diagnosis and allergens

    Which allergens were confirmed and which product is being prescribed.

  2. Technique

    Induction and dosing schedule

    How the first dose was given and the ongoing daily plan.

  3. Findings

    Baseline symptoms and asthma status

    Where you started so improvement can be measured.

  4. Impression

    Follow-up, missed-dose plan and duration

    Read this first: review dates and what to do if you miss doses.

Recognised by major UK insurers

BupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealix

SLIT is available on the NHS in specialist centres only, usually for severe cases that have failed standard treatment; it is often covered by private insurers when medically indicated.

Frequently asked

Everything we get asked about sublingual immunotherapy.

  • When is SLIT actually worth doing?

    When hay fever or house-dust-mite allergy is genuinely limiting sleep, school, work or asthma control despite antihistamines and nasal steroids, and you are willing to take a daily tablet for 3 years. It is not for mild symptoms.

  • What does SLIT involve?

    A licensed tablet placed under the tongue once a day for 3 years. The first dose is given under supervision in clinic; the rest is at home. Symptoms usually improve by the first pollen season and effects last for years after the course ends.

  • How much does SLIT cost privately in the UK?

    Roughly £900–£1,400 per year for grass pollen, £1,100–£1,600 for house-dust-mite and £1,200–£1,800 for birch - a full 3-year course typically runs £2,700–£5,400 including consultations.

  • Is SLIT available on the NHS?

    Selectively, through specialist allergy centres for severe hay fever or HDM asthma that has failed standard treatment. Access is limited and waits are long.

  • When should we start SLIT for hay fever?

    Ideally 4 months before pollen season - so January or February for grass pollen. That gives the first full summer of benefit.

  • How long does the benefit last after the course ends?

    Most studies show meaningful symptom improvement for at least 2 to 7 years after finishing a full 3-year course. Some patients need a second course later.

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