Raloxifene can be used to try to reduce the risk of breast cancer in women who are at a moderate or high risk of developing breast cancer because of a significant family history.

Find out more about family history, genes and breast cancer risk.

The National Institute for Health and Care Excellence (NICE) suggests healthcare professionals consider offering raloxifene to women who are post-menopausal (have gone through the menopause) and have not had a hysterectomy (removal of the womb) or a bilateral (double) mastectomy.

Your genetics or breast care specialist team should explain how likely it is to reduce your risk of breast cancer and any other risk-reducing treatment options.

How does it work?

Raloxifene is one of a group of drugs known as selective oestrogen receptor modulators (SERMs). SERMs act on oestrogen receptors, activating them in some parts of the body and blocking them in others. For example, raloxifene has an anti-oestrogen effect on breast tissue and the womb (uterus) but an oestrogen-like effect on the bones (this reduces the risk of developing osteoporosis).

How is raloxifene taken?

Raloxifene is taken as a tablet once a day. It’s best to take it at the same time every day. It’s usually taken for up to five years. If you’re taking it for reducing the risk of breast cancer and want to stop it sooner, talk to your genetics team.

Possible side effects

Everyone reacts differently to drugs. Some people experience more side effects than others, while some people don’t have any side effects. The side effects of raloxifene are listed below.

  • Common side effects
  • hot flushes and sweats
  • flu-like symptoms

Less common side effects

Taking raloxifene increases the risk of blood clots including deep vein thrombosis (DVT). Tell your doctor straight away if you experience symptoms such as swelling or pain in your leg (usually the calf). People with a DVT are at risk of developing a pulmonary embolism. This is when part of the blood clot breaks away and travels to the lung. If you experience shortness of breath, chest pain or cough up blood you need to see a doctor urgently.

Other less common side effects include:

  • leg cramps
  • swelling (oedema) in ankles and/or fingers
  • gallstones.

Rare side effects

  • breast symptoms such as enlargement, tenderness or pain
  • abdominal pain
  • feeling sick (nausea)
  • indigestion
  • headaches, including migraines
  • raised blood pressure
  • skin rash
  • vaginal bleeding

Support for you

Being told that you have a moderate or high risk of developing breast cancer can be very upsetting and it can be difficult to decide about risk-reducing treatments. You can call us on 0808 800 6000 to talk about your options. You can also talk to one of our volunteers through our Someone Like Me service. We can put you in touch with someone who has had to make the same sorts of decisions.

Last reviewed: March 2017
Next planned review begins underway

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