Side Effects of Tamoxifen

Tamoxifen can be used to:

• Treat hormone receptor-positive early and locally advanced breast cancers (learn more)
• Treat hormone receptor-positive metastatic breast cancers (learn more)
• Lower the risk of breast cancer for women at high risk of breast cancer who haven’t been diagnosed (learn more)

Tamoxifen can be used to treat breast cancers in women and men.

Side effects in women

Watch our MBC Impact Series, Metastatic Breast Cancer and Sexual Health. Although this webinar was created for women who have metastatic breast cancer, it has helpful information about sexual health for women with any stage of breast cancer. We encourage all to watch.

Menopausal symptoms

Menopausal symptoms, such as hot flashes, are common in women who take tamoxifen [115]. 

Although menopausal symptoms may become less frequent and less intense over time, they can still be hard to manage. If you have symptoms, talk with your health care team about ways to treat them.

Health risks

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 rare [115].

The table below lists some possible side effects and health risks of tamoxifen in women.   

Before you begin taking tamoxifen, talk with your health care team about possible side effects and how to manage them.

Side effects and health risks of tamoxifen in women
Common	Hot flashes and night sweats Irregular periods or spotting (uterine bleeding) Loss of sex drive Vaginal discharge Vaginal dryness or itching
Rare	Bone loss (premenopausal women only) Cancer of the uterus (also called endometrial cancer) Cataracts Deep venous thrombosis (blood clots in the large veins) Pulmonary emboli (blood clots in the lungs) Stroke
Adapted from Rimawi MF and Osborne CK [115].

Learn more about side effects.

Side effects in men

The table below lists some possible side effects and health risks of tamoxifen in men.

Before you begin taking tamoxifen, talk with your health care team about possible side effects and how to manage them.

Side effects and health risks of tamoxifen in men
Common	Headache Hot flashes Impotence Loss of sex drive Nausea and vomiting
Rare	Cataracts Deep venous thrombosis (blood clots in the large veins) Pulmonary emboli (blood clots in the lungs) Skin rash Stroke
Adapted from select sources [115-117].

Learn more about side effects.

Side effects of tamoxifen versus side effects of aromatase inhibitors

Although both tamoxifen and aromatase inhibitors can cause menopausal symptoms, such as hot flashes, many of their side effects differ.

Learn about how the side effects of these hormone therapies compare. 
  

Susan G. Komen® Support Resources

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