Grazax is a tablet-based immunotherapy treatment. Immunotherapy is the administration of the substance a person is allergic to in order to give them long term relief from the symptoms. More information

A doctor will review your order and write you a prescription, if appropriate. This prescription is then forwarded to a pharmacy. The pharmacy will have your medicine delivered to you within one to three working days. Read more about this process here.

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Grazax is used to build up immunity to allergy to grass pollen. This presents as hay fever (seasonal allergic rhinitis) caused by grass pollen. Grazax is an allergen immunity treatment (AIT) that slowly builds up the body’s tolerance to grass pollen. It can be taken by adults and children over 5 years of age. This medicine is used long-term to increase its effectiveness. 

What is Grazax? 

Grazax is a tablet-based immunotherapy treatment. Immunotherapy is the administration of the substance a person is allergic to in order to give them long term relief from the symptoms. Grazax stimulates the immune system and helps the body build up its negative reaction to grass pollen. It can be a successful treatment for people who are allergic to grass pollen, giving them a better quality of life. 

This medication contains an extract of the grass pollen allergen called Timothy grass (phleum pratense). Timothy grass is also known as cat’s tail and is a common type of grass that creates pollen that many people are allergic to. It is a seasonal plant and the flowers pollinate in the summer. The pollen is airborne and it is difficult to know if you have inhaled it as it is so widespread. It is useful to check the pollen count before you go outdoors in the pollen season, so you know when to avoid the high pollen times. 

Grazax is like a vaccine against an allergy to grass pollen in the form of a tablet. When you take this medication the body absorbs it and stimulates the immune system to produce antibodies to fight the allergy.  

This is a convenient way of taking immunotherapy treatment as you take one tablet once a day, under the tongue. An alternative treatment is via a monthly injection, which may not be so easy for some people. 

This medicine has to be taken long-term for it to work. It is usually taken for a minimum of 3 years to build up immunity to grass pollen.  

Grazax can only be obtained on prescription from a doctor.  

When is Grazax used? 

Grazax is used to treat allergies to grass pollen in both adults and children over the age of 5. This medication can only be used to treat grass pollen allergies and is not suitable to treat other common allergies (such as to pet dander, house dust or household chemicals). Different medications should be prescribed for these allergies. 

An allergy to grass pollen is called hay fever, or allergic rhinitis. This is a common condition that occurs during the summer months. When a person with this condition is exposed to grass pollen (the allergen) they get the symptoms of a cold (sneezing, runny nose, itchiness). The symptoms can be mild and manageable or can be severe and disrupt day to day life. Hay fever can even lead to asthma, or seasonal asthma can occur in the grass pollen season.  

The symptoms happen when the person with the allergy breathes in the grass pollen and the inside of the nose becomes swollen and inflamed. 

There are also other forms of allergic rhinitis, caused by different allergies. Grazax is specifically for an allergy to grass pollen. 

The most common grass pollen allergy is to Timothy grass. Grazax contains Timothy grass to counteract the allergy. 

Symptoms of hay fever are: 

  • Runny nose; 
  • Sneezing; 
  • Itchy nose; 
  • Itchy eyes; 
  • Cough; 
  • Fever; 
  • Sore throat; 
  • Watery eyes; 
  • Asthma. 

If you have hay fever you should: 

  • Stay indoors when the pollen count is high; 
  • Keep doors and windows shut; 
  • Avoid going outdoors to grassy areas; 
  • Not cut the grass; 
  • Wear sunglasses; 
  • Dry clothes and bedding in a dryer. 

This can make life difficult for some people, particularly as grass pollen is usually produced during the summer months when we want to spend time outdoors. Also, feeling like you have a constant cold and are unwell is not pleasant and can affect your work, studies and home life. 

The main way to diagnose hay fever is with a skin prick test. This is a fast and painless test that exposes the skin to various substances that cause allergies. It then shows if a person is allergic to any of these substances, including grass pollen.  

How do you use Grazax? 

You put one Grazax tablet under your tongue and allow it to dissolve for 1-2 minutes until it dissolves. You should not swallow during this time, to allow the medication to be absorbed.  

Do not eat or drink for a minimum time of 5 minutes after taking a Graxaz tablet.  

This kind of medication is known as an oral lyophilizate. It is placed under the tongue as the body absorbs it faster because it sends it straight into the bloodstream.  

Grazax only contains a small dose of the grass pollen allergen and it will take a while for your body to build up immunity. For this reason, you should start to take this medication at least 4 months before the beginning of the grass pollen season.  

You should then take it for 3 years (on the recommendation of your doctor) if it helps alleviate your symptoms. Treatment with Grazax is continuous, not just during the grass pollen season. 

If you forget to take a tablet you can take it as soon as you remember on that day. But you should not take a double dose the next day – just take one tablet as normal.  

Do not give your Grazax tablets to anyone else with hay fever or allergies. This is not a temporary symptom reliever and should only be taken by the person it is prescribed to. 

What dosages are there? 

The usual dose is one tablet a day for at least 3 years. This medication is taken long-term to ensure it helps build up the body’s immunity to grass pollen. 

You should be reviewed every 6 months by your doctor if you take Grazax to check it is working correctly for you. 

If you still have severe hay fever during the hay fever season you should see your doctor as this may mean the medicine is not right for you. 

What are the side effects of Grazax? 

As with all medicines, Grazax can have side effects although not everyone will get them. Different medications can affect people in different ways. 

When you first take Grazax you may find you suffer from the symptoms of your allergy, such as sneezing and swelling and itching in the mouth. These should subside after a few minutes or several hours. 

The other possible side effects of Grazax are: 

  • Feeling like you have a cold; 
  • Runny and itchy eyes; 
  • Headache; 
  • Blocked nose; 
  • Throat irritation; 
  • Itching in the ears; 
  • Coughing; 
  • Fever; 
  • Upset stomach. 

If you experience a severe reaction or difficulty breathing after taking this medication you should see a doctor immediately. 

Please read the package leaflet for a full list of the potential side effects that may occur when taking Grazax. 

When shouldn’t you use Grazax? 

Grazax may not be suitable for everyone. You should not use it if you: 

  • Are allergic to any of the excipients (the substances added to the active ingredient) listed on the package leaflet; 
  • Have cancer; 
  • Have severe asthma; 
  • Have a weak immune system; 
  • Have recently had a tooth out (this includes the loss of milk teeth in children); 
  • Have had other dental surgery or an operation on your mouth; 
  • Are under 5 years of age. 
  • History of severe anaphylatic reactions 

If you have had a tooth removed or lost one, you may continue to take Grazax after a period of 7 days, which will allow the cavity to heal. 

If you are allergic to fish it is important to tell your doctor as Grazax contains the ingredient gelatine, which is a derivative of fish. Also, if you have had a reaction to grass pollen injections in the past you should inform your doctor as this medication may not be suitable for you. 

There are no studies that indicate that it is safe for people aged 65 or over to take Grazax, therefore this is not recommended unless your doctor advises differently. 

If you are planning to get pregnant, are already pregnant or are breastfeeding it is not advisable to take Grazax and you should talk to your doctor. 

There is no interaction between Grazax and alcohol. 

This medication should not affect your ability to drive or operate machinery. 

Does Grazax interact with other medications? 

If you are taking any other medications, including herbal medicines, you should tell your doctor before taking Grazax.  

It is also important to tell your doctor if you are taking antihistamines or corticosteroids as they may need to adjust the dose. 

Where can you buy Grazax? 

You can only get Grazax with a prescription from a doctor. 

Can I get Grazax without a prescription?  

No, Grazax is not an over-the-counter medicine, you must have a prescription from a doctor for it. 


GRAZAX 75,000 SQ-T oral lyophilisate - Summary of Product Characteristics (SmPC) - (emc). (n.d.). Retrieved April 8, 2020, from 

J Allergy Clin Immunol. (2015). International Consensus On (ICON) Allergy Immunotheraphy (AIT). Retrieved from 

Canonica, G. W., & Durham, S. R. (2016, October). Allergen Immunotherapy for allergic rhinitis and asthma: A Synopsis. Retrieved April 8, 2020, from 

Grazax (grass pollen allergen extract). (2009, March 10). Retrieved April 8, 2020, from 

Assessed by:

Dr Imran Malik, General practitioner
Registration number: GMC: 4741365

Dr Imran Malik studied undergraduate medicine at King's College University in Central London and clinical studies at the prestigious King's College Hospital. He graduated with a MBBS degree in 2000 and went on to gain postgraduate memberships with the Royal Society of Medicine and also General Practice in 2006.