Aromatase inhibitorPrescription only
Letrozole
Tablet
Quick Summary
Letrozole lowers oestrogen levels.
Fertility treatment
Breast cancer
Medical Uses
Fertility treatment: Inducing ovulation, for example in PCOS.
Breast cancer: Hormone-sensitive types after menopause.
How it's taken
Take exactly as prescribed for the days your doctor specifies.
Your doctor decides the right dose for you and how long to take it.
Your doctor decides the right dose for you. Follow their instructions and the label.
Common Side Effects
Hot flushes
Common.
Joint pain
Sometimes.
Headache
Sometimes.
Interactions
Tamoxifen
Not combined.
Critical Warnings
Bone thinning
With long-term cancer treatment.
Specialist use
Fertility use needs monitoring.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Letrozole: drug information(opens in a new tab) · MedlinePlus, US National Library of Medicine
- Letrozole(opens in a new tab) · NHS