Raloxifene vs. Tamoxifen: 6 Ways These Breast Cancer Medications Compare and How to Choose
Key takeaways:
Raloxifene (Evista) and tamoxifen (Soltamox) are selective estrogen receptor modulator medications. They lower the risk of developing breast cancer in high-risk women who have gone through menopause. Tamoxifen also has a broader range of uses in breast cancer.
Tamoxifen is generally more effective than raloxifene at reducing the risk of invasive breast cancer. With a few exceptions, raloxifene prescriptions are often limited to the prevention and treatment of osteoporosis — not breast cancer.
Both medications can cause side effects. They’ve each been linked to hot flashes, vaginal dryness, and blood clots. Tamoxifen can also increase the risk of rare but serious side effects, such as uterine cancer and cataracts.
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Table of contents
The available treatment options for breast cancer are too numerous to count. Researchers have developed effective medications for the millions of people who are affected by the condition. And their work has paid off — breast cancer survivors make up almost a quarter of all cancer survivors in the U.S.
If you have breast cancer, navigating your treatment options can feel overwhelming. And if your cancer depends on estrogen for growth, it can feel even more confusing to differentiate between hormone-fighting medications like tamoxifen (Soltamox) and raloxifene (Evista).
These medications work similarly to manage breast cancer. So why is tamoxifen so common? And why does raloxifene tend to take the back seat? Knowing their differences when it comes to side effects, intended uses, and effectiveness can help you understand why your healthcare provider may prefer one medication over the other.
1. Raloxifene and tamoxifen are both selective estrogen receptor modulators
Raloxifene and tamoxifen belong to a group of medications called selective estrogen receptor modulators (SERMs). Certain breast cancers, called hormone receptor-positive breast cancers, use the hormone estrogen to grow. SERMs block estrogen’s effects to prevent cancer from growing and spreading in your body.
This isn’t all they do, though. While SERMs block estrogen activity in breast tissue, they act like estrogen in other parts of your body.
For instance, raloxifene and tamoxifen both mimic estrogen’s effect in your bones. This helps protect your bones from becoming brittle or breaking. This is especially important if you’ve gone through menopause, which causes a natural decrease in estrogen that can increase the risk of osteoporosis.
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Tamoxifen also acts like estrogen in the lining of your uterus, which can increase your risk of uterine cancer (if you’ve gone through menopause). Raloxifene doesn’t do this. It blocks estrogen activity in your uterine lining, so there’s no increased risk of uterine cancer.
2. Raloxifene prevents and treats osteoporosis
Raloxifene and tamoxifen are both FDA approved to lower the risk of breast cancer in people who have a high risk for developing it. You can take tamoxifen before or after menopause, but raloxifene should only be prescribed after you’ve gone through menopause.
There are some bigger differences, too.
Raloxifene can treat and prevent osteoporosis in postmenopausal women. It increases bone strength and decreases the risk of breaking a bone — specifically in your spine. It isn’t necessarily a first-choice medication for these uses because it hasn’t been proven to decrease hip or other non-spine fractures. But it’s still an option, especially if your risk for breast cancer is high or you can’t take bisphosphonates like alendronate (Fosamax).
Tamoxifen also increases bone strength, but it’s not officially approved for this use. And its increased risk of uterine cancer makes it a less desirable option compared to raloxifene and bisphosphonates.
3. Tamoxifen has more uses than raloxifene overall
Raloxifene has two main uses. It can prevent and treat osteoporosis, and it can decrease the risk of breast cancer in certain high-risk women.
Tamoxifen has a much broader reach. Alongside lowering the risk of breast cancer, tamoxifen can treat early and advanced estrogen receptor-positive (ER-positive) breast cancer. It’s also used to prevent breast cancer from coming back after surgery or radiation.
Tamoxifen also has a wide range of off-label uses. Healthcare providers may prescribe it in certain situations if approved medications aren't an option or limited alternatives are available. Examples include:
Advanced ovarian cancer
Certain types of uterine cancer
Non-cancerous tumors in the soft tissue surrounding your organs (desmoid tumors)
4. Raloxifene and tamoxifen have similar dosages, but there are some differences
Raloxifene and tamoxifen are prescription-only medications that come as oral tablets. You can take either one at any time of day, with or without food. You can also find them both as lower-cost generics.
They do differ in their recommended dosages, though. Raloxifene comes as a 60 mg tablet taken once a day, no matter the use. Tamoxifen comes as a 10 mg or 20 mg tablet taken once a day. The 20 mg daily dose is standard for breast cancer treatments. There is an option to take a higher dose of 20 mg twice a day, but this doesn’t seem to increase the medication’s benefit. And it could make you have more side effects.
Tamoxifen also comes as an oral liquid. This could be a benefit over raloxifene if you have trouble swallowing.
Other tamoxifen dosages
Some people take a lower dose of tamoxifen to prevent breast cancer from coming back. Some data suggests that a lower, 5 mg dose taken daily for 3 years after surgery can reduce the risk of your cancer returning.
However, this recommendation isn’t for everyone. This is only an option for people with a non-invasive, early breast cancer called ductal carcinoma in situ.
5. Both medications have their own side effects
Tamoxifen and raloxifene share several side effects. Due to how they work, many of these side effects are similar to what you might experience during menopause and include:
Hot flashes
Night sweats
Vaginal dryness
Weight gain
Swelling of the legs, ankles, and feet
More serious side effects are possible, too. Both medications have a boxed warning for increased risk of blood clots and stroke — this is the strongest warning the FDA can give a medication. Tamoxifen’s warning is specific to people with non-invasive breast cancer or who are at high risk for developing breast cancer. Raloxifene’s warning applies to all people taking the medication. Your healthcare provider can help you monitor and manage risks like these.
Contrasting side effects
Some side effects and health risks are more unique to raloxifene or tamoxifen, respectively.
Raloxifene | Tamoxifen |
Joint or muscle pain/weakness | Irregular or nonexistent periods |
Leg cramps | Vaginal discharge |
Flu-like symptoms like fever, achiness, and tiredness | Liver problems |
– | Uterine cancer (boxed warning) |
– | Vision changes caused by cataracts |
Reach out to your healthcare team if you experience any of the above side effects or notice anything unusual while taking tamoxifen or raloxifene.
6. Ways to save on raloxifene and tamoxifen
Raloxifene and tamoxifen are both available as brand-name medications. But you can also find them as lower-cost generics. GoodRx can help you navigate ways to save on your prescription.
Save with GoodRx. GoodRx can help you save over 80% off the average retail price of the generic versions of raloxifene and tamoxifen. Generic raloxifene’s price at certain pharmacies is as low as $40.98 with a free GoodRx discount. Generic tamoxifen’s price at certain pharmacies is less than $45.66 with a free GoodRx discount.
Save with patient assistance programs. If you’re uninsured or underinsured, you may be eligible for a raloxifene or tamoxifen patient assistance program. They offer the medications at no charge if you qualify.
How can I choose between raloxifene and tamoxifen?
There are many factors to consider when choosing between raloxifene and tamoxifen. Your healthcare provider will help you make the best decision.
Expected treatment benefits are one factor. If you’re at high risk of developing invasive breast cancer, raloxifene isn’t as effective as tamoxifen for reducing your risk. One study found that raloxifene 60 mg daily is only 76% as effective as tamoxifen 20 mg daily.
Your reason for taking the medication is another factor. If you haven’t gone through menopause, already have breast cancer, or need a medication to decrease the risk of breast cancer after surgery or radiation, tamoxifen may be a better choice. Raloxifene should only be taken by postmenopausal women with no prior history of breast cancer.
Pre-existing conditions might also sway you towards a certain medication. Raloxifene is likely a better choice for women with uterine cancer, those at risk for uterine cancer, or who have an intact uterus. It may also be a better choice for people who have osteoporosis and are at a high risk for developing breast cancer.
The bottom line
Raloxifene (Evista) and tamoxifen (Soltamox) are selective estrogen receptor modulators that help decrease the risk of developing breast cancer. Tamoxifen is a more common choice for this purpose, and it can also treat early and advanced estrogen receptor-positive breast cancer. Raloxifene is mostly limited to the prevention and treatment of osteoporosis in women who have gone through menopause.
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References
American Urological Association. (2020). Diagnosis and treatment of infertility in men: AUA/ASRM Guideline (2020).
Bratherton, D. G., et al. (1984). A comparison of two doses of tamoxifen (Nolvadex) in postmenopausal women with advanced breast cancer: 10 mg bd versus 20 mg bd. British Journal of Cancer.
Camacho, P. M., et al. (2020). American Association Of Clinical Endocrinologists/American College of Endocrinology Clinical Practice Guidelines for the diagnosis and treatment of postmenopausal osteoporosis— 2020 update. Endocrine Practice.
Eli Lilly and Company. (2023). Evista - raloxifene hydrochloride tablet [package insert]. DailyMed.
Ettinger, B., et al. (1999). Reduction of vertebral fracture risk in postmenopausal women with osteoporosis treated with raloxifene. Journal of the American Medical Association.
Farrar, M. C., et al. (2023). Tamoxifen. StatPearls.
Gilman, E. A., et al. (2021). Preventing breast cancer through identification and pharmacologic management of high-risk patients. Mayo Clinic Proceedings.
Goldstein, S. R. (2021). Selective estrogen receptor modulators and bone health. Climacteric.
Hansmann, A., et al. (2004). High-dose tamoxifen and sulindac as first-line treatment for desmoid tumors. Cancer.
Johnston, C. C., Jr., et al. (2000). Long-term effects of raloxifene on bone mineral density, bone turnover, and serum lipid levels in early postmenopausal women. Archives of Internal Medicine.
Lazzeroni, M., et al. (2023). Randomized placebo controlled trial of low-dose tamoxifen to prevent recurrence in breast noninvasive neoplasia: A 10-year follow-up of TAM-01 study. Journal of Clinical Oncology.
National Cancer Institute. (n.d.). Estrogen.
National Cancer Institute, Division of Cancer Control and Population Sciences. (2022). Statistics and graphs.
National Comprehensive Cancer Network Foundation. (2023). Ovarian cancer.
National Comprehensive Cancer Network Foundation. (2023). Uterine cancer, endometrial cancer, uterine sarcoma.
NuCare Pharmaceuticals, Inc. (2023). Tamoxifen citrate tablet, film coated [package insert]. DailyMed.
Rodriguez, B. S. Q., et al. (2023). Raloxifene. StatPearls.
Tahir, M. T., et al. (2022). Mastalgia. StatPearls.
Vogel, V. G., et al. (2010). Update of the National Surgical Adjuvant Breast and Bowel Project Study of Tamoxifen and Raloxifene (STAR) P-2 Trial: Preventing breast cancer. Cancer Prevention Research.
