Also known as
Other names:
- 2,2'-(5-(1H-1,2,4-triazol-1-ylmethyl)-1,3-phenylene)bis(2-methylpropionitrile)
Brand names:
- Anastro
- Arimidex
- ZD-1033
Therapeutic Goods Administration (TGA) approval
Anastrozole is listed on the Australian Register of Therapeutic Goods (ARTG) as a registered medicine.
World Anti-Doping Code Prohibited List 2025
Anastrozole is included in S4.1 Aromatase Inhibitors, Hormone and metabolic modulators of the World Anti-Doping Code (WADC) Prohibited List 2025 – Prohibited at all times. Anastrozole is a specified substance.
This substance meets at least two of the following three criteria, as determined by the World Anti-Doping Agency (WADA).
- It has the potential to enhance or does enhance sports performance
- It poses an actual or potential health risk to the athlete
- It violates the spirit of sport (as defined in The Code).
The Prohibited List is updated yearly after consultation with scientific, medical, and anti-doping experts to ensure that it aligns with the latest medical and scientific evidence and doping trends.
What is it?
Anastrozole is a selective non-steroidal aromatase inhibitor. Aromatase inhibitors effectively inhibit the enzyme aromatase which prevents the conversion of androgen to estrogen in peripheral tissue.
Uses
Anastrozole is used in the treatment of metastatic breast cancer in postmenopausal women. Anastrozole limits the growth of estrogen receptor-a-positive (ER+) breast cancer cells, as these tumours can be stimulated by estrogen.
How does it work?
Anastrozole reduces circulating oestradiol levels and does not possess any progestogenic, androgenic or estrogenic activity.
Adverse health effects and risk
In studies reported by the Therapeutic Goods Administration (TGA) state the more common adverse effects include vaginal bleeding, hair thinning, vomiting, sensory distances, hot flashes and loss of appetite.
What if an athlete has been prescribed Anastrozole for a medical condition?
Athletes that are prescribed Anastrozole for a medicinal purpose by a medical practitioner may be eligible for a Therapeutic Use Exemption (TUE).
References
- TGA (2025). Anastrozole [online] Therapeutic Goods Administration. Available at Australian PI – tradename (active ingredient)
- Bhutani K, Vishwakarma S, Yadav P, Yadav MK. The current landscape of aromatase inhibitors for the treatment of estrogen receptor-positive breast carcinoma. The Journal of Steroid Biochemistry and Molecular Biology. 2025 Mar 7:106729
- WADA (2025). The Prohibited List. [online] World Anti-Doping Agency. Available at: https://www.wada-ama.org/en/prohibited-list
- Haddad TC, Suman VJ, Giridhar KV, Sideras K, Northfelt DW, Ernst BJ, O’Sullivan CC, Singh RJ, Desta Z, Peethambaram PP, Hobday TJ. Anastrozole dose escalation for optimal estrogen suppression in postmenopausal early-stage breast cancer: A prospective trial. Clinical Cancer Research. 2024 Aug 1;30(15):3147-56
- Kijima I, Itoh T, Chen S. Growth inhibition of estrogen receptor-positive and aromatase-positive human breast cancer cells in monolayer and spheroid cultures by letrozole, anastrozole, and tamoxifen. The Journal of steroid biochemistry and molecular biology. 2005 Dec 1;97(4):360-8
- Gangadhara S, Bertelli G. Long-term efficacy and safety of anastrozole for adjuvant treatment of early breast cancer in postmenopausal women. Therapeutics and Clinical Risk Management. 2009 May 4:291-300
- Mareck U, Geyer H, Guddat S, Haenelt N, Koch A, Opfermann G, Thevis M, Schänzer W. Screening for anastrozole in doping analysis. Recent advances in doping analysis. 2005;13
- Milani M, Jha G, Potter DA. Anastrozole use in early-stage breast cancer of post-menopausal women. Clinical medicine. Therapeutics. 2009 Jan;1:CMT-S9
- Kamdem LK, Liu Y, Stearns V, Kadlubar SA, Ramirez J, Jeter S, Shahverdi K, Ward BA, Ogburn E, Ratain MJ, Flockhart DA. In vitro and in vivo oxidative metabolism and glucuronidation of anastrozole. British journal of clinical pharmacology. 2010 Dec;70(6):854-69