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Side Effects of Tamoxifen


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Breast Cancer 101 (Interactive Multimedia) - Side Effects of Tamoxifen
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If you have hormone receptor-positive breast cancer, hormone therapy with tamoxifen and/or an aromatase inhibitor is a key part of your treatment.  

Compared to chemotherapy, tamoxifen has few side effects. For example, tamoxifen does not cause hair loss. However, menopausal symptoms, like hot flashes, are common in women who take tamoxifen [60,67]. Although these symptoms may become less frequent and less intense over time, they can still be hard to manage. If you have any symptoms, talk to your health care provider. He/she can help treat many of them.  

The most serious health risks of tamoxifen, such as endometrial cancer (cancer of the lining of the uterus) and blood clots in the lungs, are very rare [60,67].  

Figure 5.10 lists some possible side effects and health risks of tamoxifen in women. 

 Figure 5.10: Side effects and health risks of tamoxifen in women 


  • Hot flashes and night sweats
  • Vaginal discharge
  • Vaginal dryness or itching
  • Irregular periods or spotting (uterine bleeding)

Less common 

  • Loss of sex drive 


  • Blood clots in the large veins (deep venous thrombosis)
  • Blood clots in the lungs (pulmonary emboli)
  • Bone loss (premenopausal women only)
  • Cancer of the lining of the uterus (endometrial cancer)
  • Cancer of the uterus (uterine cancer)
  • Cataracts
  • Stroke 
Adapted from National Cancer Institute materials [67].

In men, possible side effects include [67-68]:

  • Headache
  • Hot flashes
  • Impotence
  • Loss of sex drive
  • Nausea and vomiting
  • Skin rash

Side effects of tamoxifen versus side effects of aromatase inhibitors

Although both aromatase inhibitors and tamoxifen can cause menopausal symptoms such as hot flashes and night sweats, they have many different side effects. Learn more about how the side effects of these hormone therapies compare.

Updated 12/11/13

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