ta·​mox·​i·​fen tə-ˈmäk-sə-ˌfen How to pronounce tamoxifen (audio)
: an estrogen antagonist C26H29NO used in the form of its citrate especially to treat postmenopausal breast cancer

Examples of tamoxifen in a Sentence

Recent Examples on the Web The two drugs approved by the U.S. Food and Drug Administration for prevention, tamoxifen and raloxifene, reduce estrogen in different ways but offer the same kind of protection. Elizabeth Cooney, STAT, 13 Nov. 2023 One option is the use of presurgical endocrine therapy (give tamoxifen or an aromatase inhibitor three to four weeks before going to surgery) to measure endocrine responsiveness). Nathalie McDowell Johnson, STAT, 19 Sep. 2023 Cancer medicines cisplatin, quercetin, and tamoxifen. Megan Nunn, Pharmd, Verywell Health, 21 July 2023 For example, tamoxifen is a drug that treats and prevents breast cancer. Cynthia Sass, Mph, Rd, Health, 2 June 2023 Some evidence suggests that turmeric can reduce how much tamoxifen your body absorbs.19 Heart disease medicines: For example, turmeric may reduce how much talinolol your body absorbs. Cynthia Sass, Mph, Rd, Health, 2 June 2023 If a patient is determined to be at high risk for breast cancer, their clinician may give them tamoxifen, a hormone therapy that can prevent or slow cancer development. Claire Bugos, Verywell Health, 9 May 2023 Also called hormone therapy and often including tamoxifen, it’s intended to prevent tumor cells from spreading by choking off growth-stimulating hormones. Elizabeth Cooney, STAT, 3 May 2023 Some ways to reduce the risk of breast cancer include keeping a healthy weight, being physically active, drinking alcohol in moderation or not at all and, for some people, taking medications such as tamoxifen and breastfeeding your children, if possible. Jacqueline Howard, CNN, 2 May 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'tamoxifen.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


probably by recombination & alteration of trans-, oxy, and clomiphene

First Known Use

1972, in the meaning defined above

Time Traveler
The first known use of tamoxifen was in 1972

Dictionary Entries Near tamoxifen

Cite this Entry

“Tamoxifen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tamoxifen. Accessed 6 Dec. 2023.

Medical Definition


ta·​mox·​i·​fen ta-ˈmäk-si-ˌfen How to pronounce tamoxifen (audio)
: a selective estrogen receptor modulator that acts as an estrogen antagonist in breast tissue and is administered orally in the form of its citrate C26H29NO·C6H8O7 especially to treat breast cancer or reduce the risk of its development or reoccurrence see nolvadex

More from Merriam-Webster on tamoxifen

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!