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Find out about the targeted therapy drug olaparib, also known by its brand name Lynparza. Learn who might be offered it, how it's given and the side effects it may cause.

1. What is olaparib?

Olaparib is a targeted therapy. Targeted therapies interfere with processes in cells that help cancer grow. Olaparib belongs to a group of drugs called PARP inhibitors.

Olaparib is the drug’s non-branded name. The brand name is Lynparza.


2. Who might be offered olaparib?

You may be offered olaparib if your breast cancer is negative and you have an altered BRCA gene.

It can be used to treat:

  • Early (primary) breast cancer that has a high risk of returning
  • Breast cancer that has spread ( or )

Olaparib is given after other treatments such as chemotherapy, surgery and radiotherapy.

Primary breast cancer

If you have primary breast cancer that is hormone receptor positive you will have hormone (endocrine) therapy alongside olaparib. However, olaparib cannot be given at the same time as the targeted therapy abemaciclib.

If you have primary breast cancer that is triple negative, olaparib cannot be given at the same time as pembrolizumab.

Secondary breast cancer

If you have secondary breast cancer that is hormone receptor positive you may have had hormone therapy before having olaparib.


Olaparib is available on the NHS for primary breast cancer.

If you have secondary breast cancer, speak to your specialist about whether you can have olaparib through a compassionate access scheme. You can find out more about these on our webpage on new cancer drug treatments.

3. How olaparib works

Targeted therapies block the growth and spread of cancer.

Olaparib is a PARP inhibitor. PARP stands for poly-ADP ribose polymerase. It’s a protein that helps cells repair themselves if they become damaged. PARP inhibitors stop the PARP from repairing cancer cells.

Two inherited altered genes that increase the risk of breast cancer developing are called BRCA1 and BRCA2. Cancer cells with faulty BRCA genes are less able to repair themselves if they become damaged. PARP inhibitors can also help block the cancer cells from repairing themselves and cause them to become too damaged to survive.

4. How olaparib is given

Olaparib is taken as a tablet twice a day.

It can be taken with or without food.

How long is it given for?

Primary breast cancer

You will be given olaparib for around 1 year.

Secondary breast cancer

You’ll have olaparib for as long as your treatment team feels you’re benefitting from the drug and any side effects are manageable.

5. Side effects of olaparib

Like any drug, olaparib can cause side effects.

Everyone reacts differently to drugs and some people have more side effects than others. These side effects can usually be managed and those described here will not affect everyone.

This information does not list all the possible side effects. If you have any questions about side effects, whether they are listed below or not, talk to your treatment team.

Because olaparib may be given alongside other drugs, you may also experience side effects from these. It’s sometimes difficult to know which drug causes which side effect.

You should be given a 24-hour contact number or told who to contact if you feel unwell or are concerned about side effects at any time, including at night or at the weekend.

Common side effects

Effects on the blood

Olaparib can temporarily affect the number of blood cells in the body.

You’ll have regular blood tests to check your blood count. Blood is made up of red cells, white cells and platelets. If the number of blood cells is too low, your next treatment may be delayed or the dose reduced.

Risk of infection

Not having enough white blood cells (neutropenia) can increase the risk of getting an infection such as a urine infection, pneumonia and bronchitis.

Signs of an infection

Your treatment team may give you guidelines to follow for reporting signs of an infection. But generally you should contact your hospital immediately if you experience any of the following:  

  • A high temperature (over 37.5°C) or low temperature (under 36°C), or whatever your treatment team has advised  
  • Suddenly feeling unwell, even with a normal temperature  
  • Symptoms of an infection, for example a sore throat, a cough, a need to pass urine frequently or feeling cold or shivery 

Before you start olaparib your treatment team should give you a 24-hour contact number or tell you where to get emergency care.


Having too few red blood cells is called anaemia. If you feel particularly tired, breathless or dizzy, let your treatment team know.  

Bruising and bleeding

Olaparib can reduce the number of platelets, which help the blood to clot. You may bruise more easily, have nosebleeds or your gums may bleed when brushing your teeth. Tell your treatment team if you have any of these symptoms.

Nausea and vomiting

You may feel sick (nausea) and be sick (vomit) at times during your treatment.

If nausea and vomiting affect you, let someone in your treatment team know. Anti-sickness drugs can be prescribed to help. 

Try to eat small regular meals if possible and have regular drinks.

Extreme tiredness

Fatigue is extreme tiredness that does not go away with rest or sleep. It’s a very common side effect of breast cancer treatment and may affect you physically and emotionally.

Fatigue may affect your ability to drive or operate machinery. If you think you have fatigue, tell your GP or treatment team. They can assess you and offer advice on how to manage your energy levels.

Find out more about managing fatigue.


Olaparib may cause dizziness. If you feel dizzy, avoid driving. If dizziness persists speak to your treatment team or GP.


This is usually mild. If you have diarrhoea, drink plenty of fluids. Your treatment team or GP can prescribe drugs to help.

Contact your treatment team if you have 4 or more episodes of diarrhoea within a 24-hour period.

Other common side effects

Other common side effects of olaparib include:

  • Headaches
  • Cough or shortness of breath
  • Loss of appetite
  • Change in how things taste
  • Heartburn or indigestion
  • Skin rash

Less common side effects

Liver and kidney changes

Olaparib can affect how the liver and kidneys work. Your treatment team will arrange regular blood tests while you’re having treatment to check for this.

Other less common side effects

Other less common side effects of olaparib include:

  • Stomach pain
  • Sore mouth

6. Other important information

Allergic reaction

Very occasionally allergic reactions to olaparib can occur. Reactions can vary from mild to severe, although severe reactions are uncommon.

If you have any swelling, wheezing, chest pain or difficulty breathing after taking olaparib, contact your local A&E department, GP or treatment team immediately.

Medicines and food to avoid when having olaparib

It’s recommended you avoid grapefruit juice and bitter (Seville) oranges as these can affect how the drug works.

A number of drugs should not be taken with olaparib, so it’s important to tell your treatment team about any prescribed or over-the-counter medicines you are taking.

Ask your treatment team before taking any herbal medicines or supplements.

Sex and contraception

It’s important not to get pregnant when having olaparib as it may have a harmful effect on a developing baby.

Some women can still become pregnant even if their periods are irregular or have stopped.

Your treatment team will advise you to use 2 methods of effective contraception during treatment and for 6 months after the last dose. This should include at least 1 barrier method of contraception, such as condoms.

Men who have a female sexual partner who is pregnant or could become pregnant should use condoms while taking olaparib and for at least 3 months after the last dose. Your partner should also use an additional method of effective contraception.

If you or your partner could become pregnant, talk to your treatment team about the most suitable methods of contraception for you.


The impact of olaparib on fertility is not currently known. It’s important to discuss any fertility concerns with your treatment team before you begin your treatment.


Breastfeeding is not recommended while having olaparib, or for at least 1 month after the last dose. This is because there’s a risk the drugs could be passed on through breast milk.

Travel and vaccinations

If you’re planning a holiday or need to travel overseas, check with your treatment team first. 

You should not have any live vaccines while you’re having treatment.

Live vaccines include mumps, measles, rubella (German measles), polio, BCG (tuberculosis), shingles and yellow fever. 

Live vaccines contain a small amount of live virus or bacteria. If you have a weakened immune system, which you may do during treatment, they could be harmful.

It’s safe to have these vaccinations 6 months after your treatment finishes. Talk to your GP or treatment team before having any vaccinations.

If anyone you have close contact with needs to have a live vaccine speak to your treatment team or GP. They can advise what precautions you may need to take depending on the vaccination.

Flu vaccination 

Anyone at risk of a weakened immune system, and therefore more prone to infection, should have the flu vaccine. This includes people due to have, or already having, olaparib. 

The flu vaccine is not a live vaccine so does not contain any active viruses. Talk to your treatment team about the best time to have your flu jab.

Coronavirus (Covid-19) vaccination  

People having olaparib are advised to speak to their treatment team about the best time to have a coronavirus (Covid-19) vaccination.

The Covid-19 vaccines are not live vaccines.

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Quality assurance

Published in January 2023. Revised in April 2023. The next planned review begins in April 2025.

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