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Re: Letrozole

Hi bcrsally

Many people ask about vitamin and herb supplements as they want to do as much as possible to be healthy. There is often the belief that vitamins and herbs are safe as they are considered natural but herbal treatments don’t have to comply with the same regulations or rigorous testing that conventional medicines do. There is much we don’t know about supplements and herbal remedies.  For many products there is a lack of research to support their use and some can interfere with conventional medicines including cancer treatments. 

Although there is no information to suggest that you can’t take magnesium and zinc alongside letrozole, Echinacea can interfere with some cancer treatments.  You can search this American website here for information about individual herbs and vitamins. Each has sections on existing evidence and what known interaction there is with other medications.

You can also search herbal products and supplements on the European website Complementary and Alternative Medicine for cancer and on the American website Medicine Plus

Before taking any supplements, do speak to your breast care nurse, treatment team, your GP, or a pharmacist.  Your treatment team may recommend that you avoid, or stop taking, herbs or supplements as some of these may affects treatments such as hormone therapy, surgery, radiotherapy or chemotherapy.

Do call our Helpline if you would like to talk this through or have any further questions. Your call will be confidential, and the number is free from UK landlines and all mobile networks.

The number is 0808 800 6000 (Text relay prefix 18001).

If you would like a nurse to call you do complete this form. Ticking the box agreeing to a call back.

Our opening hours are Monday to Friday 9am - 4pm and 9am -1pm on Saturday. Out of hours you can leave a message and we will call you back when we next open.

Best wishes


Breast Cancer Now Nurse

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I have been started on Letrozole preoperatively as I have to wait 4 weeks for my wide excision and sentinel biopsy. My question is “ is it ok to take supplements alongside the Letrozole, such as magnesium and zinc, and I usually take echinacea through the winter months too!”Sally