Risk-Lowering Drugs
Tamoxifen and raloxifene are the only FDA-approved drugs for breast cancer risk reduction in women who do not have breast cancer, but are at higher risk.
You may hear the term “chemoprevention” to describe these drugs, but they aren’t chemotherapy drugs.
- Tamoxifen is used to prevent and treat breast cancer.
- Raloxifene is used to prevent breast cancer. (Raloxifene is also used to prevent and treat osteoporosis.)
Both tamoxifen and raloxifene are pills.
For a summary of research studies on tamoxifen and raloxifene and breast cancer prevention, visit the Breast Cancer Research Studies section. |
Tamoxifen and raloxifene
In women who don’t have breast cancer, but are at higher risk of breast cancer, tamoxifen and raloxifene can be used to lower risk.
Breast cancer risk
Both tamoxifen and raloxifene can lower the risk of [232]:
- Invasive breast cancer
- Non-invasive breast cancer, such as ductal carcinoma in situ (DCIS)
Tamoxifen and raloxifene only reduce the risk of estrogen receptor-positive breast cancers. Neither drug reduces the risk of estrogen receptor-negative cancers [232].
Tamoxifen is more effective than raloxifene in lowering breast cancer risk [232]. Tamoxifen lowers risk by about 50% in women at high risk [232]. Raloxifene lowers risk by about 38% in women at high risk [232]. However, raloxifene has fewer harmful side effects than tamoxifen (see table below) [232]. This makes raloxifene a better choice for some women.
Side effects
Both tamoxifen and raloxifene have some long-term side effects (see table below) and may not be right for all women at higher risk. For example, tamoxifen increases the risk of cataracts and cancer of the uterus [232].
Talk with your health care provider about the possible benefits and harms of these drugs.
Learn more about the side effects of tamoxifen.
Learn more about talking with your health care provider.
Tamoxifen versus raloxifene for breast cancer risk reduction |
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Tamoxifen |
Raloxifene |
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Who can take the drug? |
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How is the drug taken? |
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What are common short-term side effects? |
Other side effects are less common. |
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What are the possible health risks? |
These effects occur mostly in older postmenopausal women. |
These effects occur mostly in older postmenopausal women. |
What about use in breast cancer treatment? |
Effective in the treatment of hormone receptor-positive breast cancer |
Not effective for breast cancer treatment |
Adapted from selected sources [232,371-376]. |
Susan G. Komen® Support Resources |
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*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date.
Updated 04/04/23