Grazax hay fever treatment


You need to read this information with the manufacturer's leaflet that comes with your medicine.

This information answers some of the questions that you are likely to have about taking Grazax tablets for your hay fever allergy. If you have any more questions or concerns, please speak to a doctor or nurse caring for you. 

Grazax® is used to reduce allergic reactions to grass pollen. We might recommend this treatment if:

  • you have a severe allergy to grass pollen
  • your other medicine does not control your symptoms well

How Grazax treatment works

If you are allergic to grass pollen, this can cause various symptoms. They include:

When you take a Grazax tablet, you have a small amount (dose) of the grass pollen that causes your allergic reaction. This substance is called the allergen.

By taking lots of small doses, you build up a tolerance to grass pollen. This reduces the symptoms of your allergic reaction. 

Starting treatment

Your first appointment with the allergy specialist takes approximately 1 hour. Treatment is started before the grass pollen season begins.

At your first appointment, we give you a 6-month supply of Grazax tablets. 

You have a review appointment at the end of the grass pollen season.

How to take Grazax

Grazax comes as a soft, light tablet. Take it 1 time each day.

You need to take the tablet out of its original pack with dry fingers. Then put the tablet under your tongue, where it dissolves. Keep the tablet under your tongue for 1 to 2 minutes before swallowing it.

You need to avoid eating or drinking for at least 5 minutes after taking Grazax. This is to make sure that the tablet is completely dissolved.

We give you more information on how to take Grazax when we see you in the clinic.

If you forget to take Grazax

If you forget to take Grazax for 1 day, take the dose as soon as you remember.

If you miss more than 1 day of your treatment, contact your medical team as soon as possible. They can explain what to do.

Side effects

You take a small dose of grass pollen to build up a tolerance to it. This means that you get some of your usual allergy symptoms. For example, you might have a runny nose or watery eyes. You usually get these symptoms straight after you start the tablets and they gradually fade. 

Please read the manufacturer’s leaflet for more information about side effects. 

Call 999 or go to A&E if:

you have any symptoms of a severe reaction, such as:

  • feeling lightheaded or faint
  • fast, shallow breathing or other breathing difficulties
  • wheezing (breathing with a whistling or rattling sound in the chest)
  • a fast heartbeat
  • clammy skin (skin that is wet from sweating)
  • anxiety and confusion
  • collapsing or losing consciousness

Other medicines and Grazax

You can take most other medicines with Grazax. This includes your usual treatment for hay fever or asthma.

Please tell us about any medicines that you currently take. This includes:

  • any medicines prescribed for you
  • any medicines that you buy from a pharmacy or shop, such as vitamins, supplements and herbal or alternative medicines

We check to make sure that you can take the medicines with Grazax.

Talk to your doctor about any new medicines before you start them. It is important to tell any other doctor who treats you that you take Grazax.

Vaccinations and other medical procedures

If you have any vaccines (such as the flu vaccine), you can take Grazax on the day of your vaccine if you are fit and well.

You need to tell your doctor or dentist that you take Grazax before you have any medical or dental procedures.

If you have dental surgery (for example, to remove a tooth), you need to stop Grazax for 7 days afterwards. The same applies to young children who lose their milk teeth. This gives time for the cavity (hole) to heal.

Always contact your clinic for advice on stopping and re-starting treatment.

Pregnancy and breastfeeding

It is not known how Grazax affects an unborn baby. There is limited evidence available about using Grazax during pregnancy. For this reason, we do not generally recommend taking Grazax when you are pregnant.

If you get pregnant during your treatment with Grazax, you might need to stop the treatment. Please contact your doctor if you become pregnant, or think that you might be pregnant, during treatment.

The doctor needs to check your general health and find out if the treatment has caused you any problems in the past. They can then recommend if you should keep taking Grazax. 

There is no information available about if Grazax is found in breast milk. We recommend that you do not start treatment while you are breastfeeding. Please speak to your doctor for more advice.

Review appointment

Your allergy specialist gives you a review appointment 5 to 6 months after you start Grazax treatment. This is at the end of the pollen season.

At your review appointment, you complete a questionnaire about your quality of life. We can then check if your treatment helps and explain if you need to continue it. If the treatment helps, we give you another 6-month supply of Grazax tablets.

If Grazax improves your symptoms, you will continue taking it for 3 years. If your symptoms do not improve at the end of the pollen season, your allergy specialist might stop the treatment. 

Resource number: 2344/VER3
Last reviewed: July 2022
Next review: July 2025

Contact us

If you have any questions or concerns, please contact the allergy nurse specialist.

Phone: 020 7188 5830, Monday to Friday, 9am to 5pm

Please call at least 5 working days before your appointment.

If you call out of hours, please leave your name and phone number. A member of staff will call you back in working hours.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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