Coronavirus and cancer

We know it’s a worrying time for people with cancer, we have information to help. If you have symptoms of cancer contact your doctor.

Read our information about coronavirus and cancer

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Fulvestrant (Faslodex)

Fulvestrant (pronounced full-vest-rant) is also called Faslodex. It is a hormone treatment for post menopausal women with advanced breast cancer.

How fulvestrant works

The female sex hormones oestrogen and progesterone stimulate some breast cancers to grow. These breast cancers are called hormone sensitive or hormone receptor positive.

Drugs that block the effects of these hormones can slow or stop the growth of breast cancer cells.

Fulvestrant stops oestrogen getting to the cancer cells by blocking oestrogen receptors and reducing the number of receptors the cancer cells have.  

How you have fulvestrant

You have fulvestrant as two injections – one into each buttock. You can have it at your GP surgery. Your doctor or practice nurse gives you the injections.

You have the injections every 2 weeks for the first 3 doses and then monthly. Each injection takes 1 to 2 minutes.


You might have blood tests before starting treatment and during your treatment. They check your general health and might check your levels of blood cells and other substances in the blood.

Side effects

We haven't listed all the side effects. It is very unlikely that you will have all of these side effects, but you might have some of them at the same time.

How often and how severe the side effects are can vary from person to person. They also depend on what other treatment you are having. For example, your side effects could be worse if you are also having other drugs or radiotherapy.

When to contact your team

Your doctor or nurse will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

  • you have severe side effects 
  • your side effects aren’t getting any better
  • your side effects are getting worse
Early treatment can help manage side effects better.

Common side effects

Each of these effects happens in more than 1 in 10 people (10%). You might have one or more of them. They include:

Tiredness and weakness (fatigue)

You might feel very tired and as though you lack energy.

Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.

Feeling Sick 

Feeling sick is usually mild. Anti sickness tablets can control it if you need them. Tell your doctor or nurse if you feel sick. 

Menopausal symptoms 

Menopausal symptoms can be difficult to cope with. They include:

  • hot flushes
  • reddening of the skin
  • sweating
  • a racing heart (palpitations)
  • feeling anxious, irritable or panicky

Talk to your doctor if your symptoms are hard to cope with.  They might be able to prescribe medicine. We also have tips on how to cope with them.

Soreness and swelling around the injection site 

Tell your nurse if you notice any signs of redness or irritation around the injection site.

This can last for 1 or 2 days after the injections. 

Liver changes 

You might have liver changes that are usually mild and unlikely to cause symptoms. They usually go back to normal when treatment finishes. You have regular blood tests to check for any changes in the way your liver is working.

Skin rash

Skin problems include a skin rash, dry skin and itching. This usually goes back to normal when your treatment finishes. Your nurse will tell you what products you can use on your skin to help.

Allergic reaction

A small number of people have an allergic reaction.

Symptoms include a skin rash, itching, feeling hot and shivering. Other symptoms include redness of the face, dizziness, a headache, shortness of breath and anxiety. Tell your nurse or doctor immediately if you have any of these symptoms.

Your nurse will keep a close eye on you and give you treatment immediately if this happens.

Joint pain 

You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.

Occasional side effects

Each of these effects happens in more than 1 in 100 people (1%). You might have one or more of them. They include:

  • headaches
  • being sick
  • diarrhoea
  • loss of appetite
  • increased risk of blood clots
  • urine infection
  • back pain
  • breathlessness and cough
  • constipation
  • vaginal bleeding
  • bruising, bleeding gums or nosebleeds

Rare side effects

Each of these effects happens in fewer than 1 in 100 people (1%). You might have one or more of them. They include:

  • weakening of the bones (osteoporosis)
  • liver failure

What else do I need to know?

Other medicines, foods and drink

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.


This drug contains very small amounts of alcohol. This is not harmful to most people but may be harmful if you have alcohol problems.

Treatment for other conditions 

Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

Information and help