MedicinePOMEssential

Letrozole

Letrozole (Femara) is a hormone-blocking tablet that treats breast cancer and helps stop it returning.

Clinical information

Common uses

hormone-dependent breast cancer after menopause
preventing breast cancer coming back
shrinking breast cancer before surgery
occasionally as a fertility treatment

Common side effects

hot flushes and sweating
tiredness
low mood
feeling or being sick
mild muscle or bone aches

Cautions

can weaken bones (osteoporosis) — bone density scans needed
can raise blood pressure and cholesterol
usually not suitable if you still have periods
do not stop without talking to your doctor

Interactions

HRT and oestrogen-containing menopause medicines (avoid)
herbal menopause remedies (avoid)

Pregnancy: not recommended — tell your doctor urgently if pregnant

Reference information, not medical advice — always follow your doctor or pharmacist. Source: NHS Medicines A–Z, nhs.uk/medicines/letrozole (accessed 2026-08-16)

Approved brands & formulations3

Brand name	Dosage form	Strength	Importer	Category
Arofrez Tablet 2.5mg	Tablet	2.5mg	—	POM
Lentronat	Tablet	2.5mg	authorized medicine importers	POM
Letrozole	Tablet	2.5mg	—	POM