Raloxifene is a type of drug called a selective oestrogen receptor modulator (SERM). You pronounce raloxifene as ral-ox-e-feen.

You might have it as a treatment to:

  • lower the risk of breast cancer if you have a high or moderate risk of developing it
  • prevent and treat bone thinning (osteoporosis)

Raloxifene is only for women who no longer have their periods (post menopausal).  

Doctors prescribe raloxifene off label. This means it is not licenced as a treatment to lower the risk of breast cancer. But it is recommended for this by the National Institute for Health and Care Excellence (NICE).

How does raloxifene work?

Raloxifene acts like the female sex hormone Open a glossary item oestrogen, although it isn't a hormone. It copies how the oestrogen works and is able to increase the thickness (density) of the bone to prevent and treat bone thinning.

To prevent breast cancer raloxifene is able to block the hormone oestrogen. Some breast cancer cells need hormones such as oestrogen and progesterone to grow. Raloxifene stops oestrogen from encouraging breast cancer cells to grow.

How do you have raloxifene?

Raloxifene is a tablet that you swallow.

You must take tablets according to the instructions your doctor or pharmacist gives you.

You should take the right dose, not more or less.

Talk to your healthcare team before you stop taking a cancer drug, or if you miss a dose.

How often do you have raloxifene?

You take raloxifene once a day. You can choose the best time to take it but try to take it at about the same time every day. If you are taking it to reduce the risk of breast cancer, you take it for 5 years.

Ask your doctor how long you should take raloxifene. They may also advise you to take calcium and vitamin D supplements.

What are the side effects of raloxifene?

Side effects can vary from person to person. They also depend on what other treatment you are having. 

When to contact your team

Your doctor, nurse, or pharmacist 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.

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

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Hot flushes or sweats

We have some tips for coping with hot flushes in women. We also explain some of the possible treatments. Talk to your doctor if your hot flushes are hard to cope with. They might be able to prescribe you some medicines.

Flu-like symptoms

You may have headaches, muscle aches (myalgia), a high temperature and shivering. You should contact your advice line urgently if you have these symptoms.

Feeling or being sick

Feeling or being sick is usually well controlled with anti sickness medicines. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.

Tummy (abdominal) pain

Tell your treatment team if you have this. They can check the cause and give you medicine to help. 

Indigestion or heartburn

Contact your doctor or pharmacist if you have indigestion or heartburn. They can prescribe medicines to help.

High blood pressure

Tell your doctor or nurse if you have headaches, nosebleeds, blurred or double vision or shortness of breath. You have your blood pressure checked regularly.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have on or more of them. They include:

  • swelling of your hands and legs due to a build up of fluid (oedema)

  • headaches or a throbbing pain in the front or side of your head (migraine)

  • leg cramps

  • a skin rash

  • breast tenderness or pain that is usually mild

  • an increase in the size of your breasts

Rare side effects

These side effects happen in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:

  • blood clots in the legs, lungs or eyes that can be life threatening; signs are pain, swelling and redness where the clot is. Feeling breathless can be a sign of a blood clot in the lung. Contact your advice line or doctor straight away if you have these

  • a stroke which can be life threatening - symptoms can be a drooped face, numb or weak arms, slurred speech or not being able to speak

  • bruising or bleeding due to a low number of platelets in the blood

  • liver changes that usually go back once treatment finishes – you have regular blood tests to check this

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do I need to know?

Other medicines, foods and drink

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

Pregnancy and contraception

This drug is only used for women who have been through the menopause. You should not take this medicine if you can still have a baby. This drug may harm a baby developing in the womb.

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you become pregnant while having treatment.

Treatment for other conditions

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

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

Related links