Tamoxifen / Black Cohosh

Original Question: I have heard of the herb Black Cohosh being used to try and help alleviate hot flushes while a person is using Tamoxifen. I am not sure as to whether it is advisable to use this herb as well as the drug. Have you had experience with people using the two together or can give any advice on this option??

…………….Hot flushes are a frequent adverse effect of Tamoxifen therapy. I have often wondered myself whether it was advisable to use Black Cohosh to help reduce these adverse effects while the patient remained on Tamoxifen.

In doing some research I have read of two clinical trials evaluating the combined administration of Black Cohosh with Tamoxifen or Black Cohosh alone in women who have had breast cancer.

In the first using premenopausal breast cancer survivors on Tamoxifen treatment it was found that Black Cohosh may be a useful adjuvant therapy for the treatment of hot flushes in breast cancer survivors using Tamoxifen, as the frequency of hot flushes reduced and were less severe.

In the second study this observation was not upheld. However this study was of much shorter duration. More and longer trials are needed.

A recent review of these studies stated that Black Cohosh has a relatively good safely record, but that the effectiveness of the herb in regards to treatment remained inconclusive.
My own observations in clinical practice would agree with this conclusion. I have in some cases seen what the patient regarded as discernable improvement but this does not happen in every case.

The mechanism of action for Black Cohosh is thought to be via action in the brain rather than through any oestrogenic effect. It appears to be safe even in women at risk for breast cancer as well as breast cancer survivors.

A study in breast cancer cell lines showed Black Cohosh extract exerts no prolific activity
on these cells, but actually promotes both oestrogen receptor positive and receptor negative breast cancer cells to commit cellular suicide (apoptosis), however to my knowledge this also has not been studied over the long term.

If deciding to use Black Cohosh please consult with your doctor so that progress can be monitored safely.