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Fulvestrant for breast cancer


Fulvestrant injection will be given to you by your doctor or nurse. Try to keep your appointments so that you receive the injections on time.

The most common side-effects are feeling tired, feeling sick (nausea), and pain at the site of the injection.

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About fulvestrant

Type of medicine

An anti-oestrogen hormone antagonist

Used for

Breast cancer in women

Also called


Available as


Fulvestrant is a hormonal breast cancer treatment. It is used to treat advanced breast cancer and metastatic breast cancer. Advanced breast cancer is cancer which has progressed despite treatment, and metastatic breast cancer is cancer which has spread into other parts of the body.

Many breast cancers need the female hormone oestrogen to grow. The cells of these cancers have tiny areas called receptors on their surface, to which oestrogen can attach. They are called 'hormone receptor-positive' cancers. Fulvestrant works by blocking the receptors and this prevents oestrogen from reaching the cancer cells. This slows the growth of the cancer.

Before having fulvestrant

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start having fulvestrant injections it is important that your doctor or nurse knows:

  • If you have not yet gone through the menopause, or if there is a possibility you could be pregnant.

  • If you have any problems with the way your liver works, or any problems with the way your kidneys work.

  • If you have any blood clotting problems or bleeding disorders.

  • If you have ever had an allergic reaction to a medicine.

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

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How fulvestrant will be administered

  • Before you start the treatment, ask to read the manufacturer's printed information leaflet from inside the pack. It will give you more information about fulvestrant and it will also provide you with a full list of the side-effects which you could experience from having it.

  • Your doctor or nurse will give you the fulvestrant injection. He or she will give you an injection every two weeks to begin with (for the first three doses); after that it will be given once each month. It will be injected slowly over a couple of minutes into muscles in your bottom. For each dose, you will be given an injection into both buttocks.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor or clinic. This is so your doctor can check on your progress. You may need to have a blood test from time to time.

  • Fulvestrant injection contains a small amount of alcohol. This is usually harmless, but if you have ever had a problem with an addiction to alcohol, you should let your doctor know about this.

  • It is important that you do not get pregnant while you are having treatment with fulvestrant. Make sure you have discussed with your doctor which types of contraception are suitable for you and your partner. You should continue to use contraception for two years after your treatment has finished.

  • If you are due to have an operation, tell the person carrying out the treatment that you are having fulvestrant treatment.

  • If you buy any medicines 'over the counter', always check with a pharmacist that they are suitable to take alongside your prescribed medicines.

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Can fulvestrant cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with fulvestrant. The best place to find a full list of the side-effects which can be associated with your medicine, is from the manufacturer's printed information leaflet supplied with the medicine. Alternatively, you can find an example of a manufacturer's information leaflet in the reference section below. Speak with your doctor or pharmacist if any of the following continue or become troublesome.

Very common

fulvestrant side-effects (these affect more than 1 in 10 women)

What can I do if I experience this?

Feeling sick (nausea)

Stick to simple meals - avoid fatty or spicy foods

Feeling weak or tired

Do not drive and do not use tools or machines while affected

Pain or inflammation at the injection site

Speak with your doctor if troublesome

Joint or muscle pains

Ask your pharmacist to recommend a suitable painkiller. If the pain continues, speak with your doctor

Changes to liver enzymes

Your doctor will arrange for you to have blood tests to check for this


fulvestrant side-effects

(these affect fewer than 1 in 10 women)

What can I do if I experience this?


Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, speak with your doctor

Hot flushes

Try to keep cool by wearing light, airy clothes


Drink plenty of water to replace any lost fluids

Loss of appetite, urine infections, back pain

Speak with your doctor about these

Important: your doctor will discuss with you the possibility of more serious side-effects. These are listed below. You must let your doctor know straightaway if any happen to you:

  • Any pain or swelling in your lower leg. This is because taking fulvestrant can increase the risk of you developing a blood clot in your legs.

  • Any swelling of your face or throat, feeling short of breath, or a severe skin rash. These could be signs of an allergic-type reaction.

If you experience any other symptoms which you think may be due to the injection, speak with your doctor or pharmacist for further advice.

How to store fulvestrant

  • If you are asked to store fulvestrant injection, keep it in a refrigerator at 2-8°C.

  • Keep all medicines out of the reach and sight of children.

Important information about all medicines

Important information about all medicines

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about the medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article History

The information on this page is written and peer reviewed by qualified clinicians.

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