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.

Tamoxifen has fewer side effects than chemotherapy. For example, tamoxifen doesn’t cause nausea.

Side effects in women

Menopausal symptoms, such as hot flashes, are common in women who take tamoxifen [102]. 

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 provider about ways to treat 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 rare [102].

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

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	Blood clots in the large veins (deep venous thrombosis) Blood clots in the lungs (pulmonary emboli) Bone loss (premenopausal women only) Cancer of the uterus (uterine or endometrial cancer) Cataracts Stroke
Adapted from Rimawi MF and Osborne CK [102].

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

Side effects in men

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

Side effects and health risks of tamoxifen in men
Common	Headache Hot flashes Impotence Loss of sex drive Nausea and vomiting
Rare	Blood clots in the large veins (deep venous thrombosis) Blood clots in the lungs (pulmonary emboli) Cataracts Skin rash Stroke
Adapted from select sources [102-104].

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

Side effects of tamoxifen versus side effects of aromatase inhibitors

Although both aromatase inhibitors and tamoxifen 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

If you or a loved one needs more information about breast health or breast cancer, contact the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email helpline@komen.org. All calls are answered by a trained specialist or oncology social worker, Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. Se habla español. Komen Patient Navigators can help guide you through the health care system as you go through a breast cancer diagnosis and treatment. They can help to remove barriers to high-quality breast care. For example, they can help you with insurance, local resources, communication with health care providers and more. Call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email helpline@komen.org to learn more about our Patient Navigator program, including eligibility. Komen’s Breast Cancer Facebook Group and Metastatic Breast Cancer Facebook Group provide places where those with a connection to breast cancer can share their experiences and build strong relationships with each other. Our fact sheets, booklets and other education materials offer additional information.