Tamoxifen? Arimidex? Aromiasin? which one to take

How does the onc decide which hormone therapy to prescribe? everyone seems to be on something different. Does it depend if you are pre-menopausal? I’m 38 and my onc has only mentioned Tamoxifen to me but from reading threads I get the impression younger women like me are on Arimidex and sometimes both? I’m confused??

Hi there eal69eal

Here’s the link to our Tamoxifen and Arimidex factsheets which you may find helpful to read as they explain who can take them and when they are prescribed:



You may also find that it helps to speak to someone about any concerns you have, please feel free to contact our Helpline on 0808 800 6000.

Everyone working on our helpline either has experience of breast cancer or is a breast care nurse and has an excellent knowledge of breast cancer issues. They also receive daily information on new developments.

The helpline is open Monday - Friday, 9am - 5pm and Saturday, 9am - 2pm.

I do hope this information is helpful

Best wishes

Hi there
My BC nurse explained it to me like this. Tamoxifen blocks oestrogen produced in the ovaries and Arimidex doesn’t, it only blocks production in fatty tissue. That is why Tamoxifen is given until it is thought that your ovaries have stopped producing oestrogen. I am taking Tamoxifen for a year before going onto Arimidex, I am 52.
Best wishes