Tamoxifen (Nolvadex) has been used for over 40 years to treat hormone-receptor positive early, locally advanced and metastatic breast cancers.

Learn about tamoxifen and other hormone therapies (endocrine therapies) for metastatic breast cancer.

How does tamoxifen work?

Hormone receptor-positive breast cancers need estrogen and/or progesterone (female hormones) to grow.

Tamoxifen attaches to the hormone receptors in the cancer cell, blocking estrogen from attaching to the receptors. This slows or stops the growth of the tumor by preventing the cancer cells from getting the hormones they need to grow.

Tamoxifen as breast cancer treatment

Tamoxifen lowers the risk of [91]:

• Breast cancer recurrence
• Breast cancer in the opposite breast
• Death from breast cancer

Tamoxifen is a pill taken every day for 5-10 years. For premenopausal women, tamoxifen may be combined with ovarian suppression.

The benefits from tamoxifen last long after you stop taking it.

Learn about the importance of completing treatment with tamoxifen.

Find a list of questions on hormone therapy (endocrine therapy) for your health care provider.

For a summary of research studies on tamoxifen for early breast cancer, visit the Breast Cancer Research Studies section.

Taking tamoxifen for more than 5 years

Findings from a large randomized clinical trial showed taking tamoxifen for 10 years reduced the risk of breast cancer recurrence and death more than taking tamoxifen for 5 years [99].

These findings have led to increased use of tamoxifen for more than 5 years, especially among premenopausal women who can’t take aromatase inhibitors and women with higher stage breast cancers.

Taking tamoxifen for a longer time means a continued risk of health effects, such as endometrial cancer [99]. For premenopausal women, tamoxifen may also impact fertility.

Discuss the benefits and risks of taking tamoxifen for more than 5 years with your health care provider.

Learn more about tamoxifen and fertility. 

SUSAN G. KOMEN® SUPPORT RESOURCES

If you or a loved one needs more information about breast health or breast cancer, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636). All calls are answered by a trained specialist or oncology social worker in English and Spanish, Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. You can also email the helpline at helpline@komen.org.  We offer an online support community through our closed Facebook Group – Komen Breast Cancer group. The Facebook group provides a place where those with a connection to breast cancer can discuss each other’s experiences and build strong relationships to provide support to each other. Visit Facebook and search for “Komen Breast Cancer group” to request to join the closed group. Our fact sheets, booklets and other education materials offer additional information.

 

Importance of following your breast cancer treatment plan

Breast cancer treatment is most effective when all parts of the treatment plan are followed as prescribed.

Prescription drug assistance

Hormone therapy drug costs can quickly become a financial burden for you and your family.

Medicare and many insurance companies offer prescription drug plans. One may already be included in your policy or you may be able to buy an extra plan for prescriptions.

Tamoxifen is a pill, so it’s covered under your health insurance plan’s prescription drug benefit rather than the plan’s medical benefit. This means there are usually out-of-pocket costs, which can add up over time.

You may qualify for programs that help with drug costs or offer low-cost or free prescriptions.  

Tamoxifen has a generic form. Generics cost less than name brand drugs, but are just as effective.

Learn more about insurance plans and prescription drug assistance programs. 

Learn about other financial assistance programs.

Susan G. Komen®’s position on fairness in oral cancer drug coverage

Insurance coverage of oral cancer drugs Cancer medications given by vein (through an IV) are usually covered under a health insurance plan’s medical benefit. However, cancer medications that are pills (oral cancer drugs) are usually covered under a health insurance plan’s prescription drug benefit. As a result, people often find themselves facing high out-of-pocket costs when filling prescriptions for oral cancer drugs. Sometimes this can cost thousands of dollars a month. The impact of high cost-sharing High prescription drug costs and the resulting out-of-pocket burden on patients are a barrier to care. They can prevent people from getting the medications prescribed by their health care providers. No one should be forced to get less appropriate treatment because an insurer gives more coverage for IV drugs than pills. Efforts to increase fairness in drug coverage Komen supports state and federal efforts to require insurers to provide the same or better coverage for oral cancer drugs as they do for IV cancer drugs. This would help ensure patients have access to affordable, appropriate treatment. Become a Komen Advocacy Insider Sign up to be a Komen Advocacy Insider and get informed when action is needed on drug coverage issues at the state or national level.

 

Komen Treatment Assistance Program

Susan G. Komen® created the Komen Treatment Assistance Program Susan G. Komen® created the Komen Treatment Assistance Program to help those struggling with the costs of breast cancer treatment by providing financial assistance to eligible individuals. Funding is available for eligible individuals of any age undergoing breast cancer treatment, at any stage of the disease. To learn more about this program and other helpful resources, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email helpline@komen.org.

 Updated 05/20/21