Compare Arimidex vs. Nolvadex

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Arimidex (anastrozole)

Prescription only

Nolvadex (Tamoxifen)

Prescription only

Treats breast cancer in postmenopausal women

Arimidex (anastrozole) is one of the first-line treatments for breast cancer that helps improve survival rates, but it is used only in post-menopausal women.

Lowers risk of and treats breast cancer.

Nolvadex (Tamoxifen) is an effective, first-line option for certain types of breast cancers, but it has many severe side effects and needs a lot of monitoring.

Upsides

Available as a pill unlike some chemotherapies.
Can be used safely and effectively even in those with kidney or liver problems.
Available as a generic version
Can be used as first line or second line hormone therapy for certain advanced breast cancers.

In studies, postmenopausal women who were at high risk for breast cancer took Nolvadex (Tamoxifen) for 5 years and lowered their risk by about 50%.
Nolvadex (Tamoxifen) is the only medicine approved to lower risk of breast cancer regardless of menopausal status. Other medicines are approved only for postmenopausal women.
Effective in treating metastatic breast cancer in men and women.
Available in both tablets and a sugar-free solution.

Downsides

Arimidex (anastrozole) can cause serious allergic reactions, such as rash, hives, tightness in the chest or throat, and trouble breathing.
You will have to get your blood drawn regularly while on Arimidex (anastrozole).
Unlike other chemotherapies, Arimidex (anastrozole) reduces the amount of estrogen in your body, which can lead to weaker bones and other symptoms typically only seen in postmenopausal women.

If you're taking Nolvadex (Tamoxifen) to lower your risk for breast cancer, it can raise your risk of having a stroke or getting a blood clot, especially if you have a history of blood clots or you're currently taking a blood thinner, like warfarin. Tell your doctor about any health conditions before you start taking Nolvadex (Tamoxifen).
Can raise the risk of fractures in premenopausal women.
There are many drug interactions, including antidepressants and other chemotherapy (anti-cancer) medicines. Talk to your doctor or pharmacist before making any changes.
Requires regular blood tests and doctor exams to monitor for side effects.
Not the best choice if you have eye or liver problems.

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