This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Letrozole is a medicine used to treat breast cancer and help to prevent breast cancer coming back.
It's mainly prescribed for women who have been through the menopause and have a type of cancer called hormone-dependent breast cancer.
Most people who take letrozole will have had primary treatment such as surgery, radiotherapy or sometimes chemotherapy to treat their breast cancer first. Letrozole is an additional (adjuvant) treatment which helps stop the cancer coming back.
Letrozole is available on prescription only and comes as tablets.
It can also be used:
- to prevent breast cancer if you're high risk and have been through the menopause
- to treat cancer if you cannot have surgery, or to shrink the cancer before surgery if you cannot have chemotherapy
It can sometimes be used to treat breast cancer in men, or in women who have not reached the menopause.
Letrozole can occasionally be used as a fertility treatment if you have polyendocrine metabolic ovarian syndrome (PMOS). If you're taking it as a fertility treatment and you need more information, speak to your specialist.
View the original NHS website page ↗. Refreshed 19 August 2026.
Licensed under the Open Government Licence v3.0 ↗. MyPHU is independent and is not endorsed by the NHS.