Browser does not support script.
Skip to main content
Find out how we produce our information|
Tamoxifen| is an anti-oestrogen drug. It works by preventing oestrogen in the body from attaching to breast cancer cells and encouraging them to grow. Tamoxifen is the standard hormonal therapy| for premenopausal women with breast cancer but it can also be given to some postmenopausal women.
Tamoxifen is taken daily as a tablet. The side effects are similar to the effects of the menopause and may include:
Tamoxifen can slightly increase the risk of womb (endometrial) cancer| in postmenopausal women. Always tell your doctor if you have any abnormal vaginal bleeding. Tamoxifen may also slightly increase the risk of blood clots in the leg and lungs. Tell your doctor straight away if you have pain, warmth, swelling or tenderness in an arm or leg, or any chest pain.
Although this sounds frightening, these side effects are uncommon and the benefits of taking tamoxifen outweigh the risks for most women. If they do happen, they can usually be treated successfully.
Tamoxifen is sometimes used instead of an aromatase inhibitor (AI)| in women who have problems with their bones, as it doesn’t cause bone thinning in postmenopausal women.
We have more detailed information on tamoxifen|, including how it works, how it’s taken and the side effects it may cause.
Content last reviewed: 1 August 2011
Next planned review: 2013
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.
If you have any questions about Macmillan we would love to hear from you| .
You can also follow us| on Facebook, Twitter, Flickr or YouTube.
© Macmillan Cancer Support 2013
what are these?|