Need emergency help? Call 999 in United Kingdom.

Open local help

Detailed medicine guidance

Pregnancy, breastfeeding and fertility while taking anastrozole

NHS medicines information on anastrozole and whether you can take it while pregnant or breastfeeding.

About this information

This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.

Anastrozole and pregnancy

Anastrozole is not recommended when pregnant.

This is because it affects hormone levels in you and your baby. There's not enough information available to say if it's safe.

Talk to your doctor straight away if there's any chance that you could be pregnant.

Anastrozole and breastfeeding

Anastrozole is not recommended while you're breastfeeding.

There's no information about how much anastrozole passes into breast milk but it's likely to be a fairly high amount compared to most other medicines.

Anastrozole affects hormones, which may affect how your baby develops.

Anastrozole and fertility

Anastrozole is generally only given to you if you have gone through the menopause.

However, some people find that they start having periods again after taking anastrozole. If this happens to you, it's important to use reliable contraception.

Talk to your doctor if your periods start again, or if there's any chance you could be pregnant.

Meds New IA (H2) - Pregnancy non-urgent care card

Tell your doctor if you're:

  • trying to get pregnant
  • pregnant
  • breastfeeding

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.

More about Anastrozole