DNC News


What about Tamoxifen?

May 6, 2005

Subject: Black Cohosh Extracts increase benefit of tamoxifen therapy without increasing risk.


Our recent article about Black Cohosh and it's varying effect on chemotherapy prompted the simple question, “What about Tamoxifen?”


Recall our article how Black Cohosh increases the cancer killing effect of Adriamycin and decreases the effect of Cisplatin or read it at:




A reader prompted me to see what information has been published regarding use with Tamoxifen. From what I've read so far, it sounds like a good idea.


Freudenstein and his colleagues at Schaper & Brummer , Germany 's major manufacturer of Black Cohosh extracts, have published a number of interesting papers on Cohosh. In November, 2002, their paper in Breast Cancer Research and Treatment looked at the effect of combining tamoxifen and Cimicifuga racemosa extracts on the growth inhibition of breast cancer cells. The herbal extract inhibited growth of breast cancer cells on its own and significantly increased the effect of the tamoxifen when given together.


What about side effects? Tamoxifen is clearly a drug with risks and benefits. Women taking tamoxifen have a 1 in 500 risk of developing endometrial.


The same fellow, Freudenstein published a paper in May, 2004 looking at the effect of Cohosh on endometrial cancer. Either alone or in combination with tamoxifen, Cohosh extracts appear to have no effect on the growth or spread of endometrial cancer. This is good news. Black Cohosh increases the benefit of tamoxifen at lowering cancer risk without increasing the risk of endometrial cancer associated with its use.


So our current bottom line is that Black Cohosh is added to the list of beneficial supplements to take in conjunction with tamoxifen therapy for breast cancer. To see the full list of things which improve the benefit or lower the risk of tamoxifen therapy, go to:






Breast Cancer Res Treat. 2002 Nov;76(1):1-10.

Influence of Cimicifuga racemosa on the proliferation of estrogen receptor-positive human breast cancer cells.

Bodinet C, Freudenstein J.


Research and Development Department, Schaper & Brummer GmbH & Co. KG, Salzgitter , Germany .


Hormone replacement therapy, which is a common menopausal treatment, is contraindicated in women with breast cancers due to concerns regarding the potential for breast cell proliferation. As such, there is a need for alternative methods for treating menopausal symptoms. To determine the influence of one such alternative, black cohosh (Cimicifuga racemosa [CR]), on estrogen-dependent mammary cancers, we conducted an in vitro investigation of the effect of an isopropanolic CR-extract on the proliferation of estrogen receptor-positive breast cancer cells. The experiments were performed using the human breast adenocarcinoma (MCF-7) cell test system, an established in vitro model for estrogen-dependent tumors. The influence of CR-extract on the proliferation of the MCF-7 cells was determined by measuring the incorporation of radioactively labeled thymidine. Under estrogen-deprived conditions, the CR-extract (10(-3)-10(-5) dilutions) significantly inhibited MCF-7 cell proliferation. Additionally, application of the CR-extract inhibited estrogen-induced proliferation of MCF-7 cells. Moreover, the proliferation-inhibiting effect of tamoxifen was enhanced by the CR-extract. Such data that suggest a non-estrogenic, or estrogen-antagonistic effect of CR on human breast cancer cells lead to the conclusion that CR treatment may be a safe, natural remedy for menopausal symptoms in breast cancer.


PMID: 12408370 [PubMed - indexed for MEDLINE]



Toxicol Lett. 2004 May 2;150(3):271-5.

Concomitant administration of an isopropanolic extract of black cohosh and tamoxifen in the in vivo tumor model of implanted RUCA-I rat endometrial adenocarcinoma cells.

Nisslein T, Freudenstein J.


Schaper & Brummer Co., R & D-Department of Veterinary Medicine, Bahnhofstr. 35, 38259 Salzgitter , Germany . thomas.nisslein@schapper-bruemmer.de


Black cohosh is a well known herbal remedy of long traditional use against menopausal complaints. Recently published studies on postmenopausal hormone replacement with synthetic substances associated severe negative side effects with an increase in duration of administration. The subsequent popularity of alternative treatments, often herbal drugs, made investigations into the safety of these preparations more pressing. Until now, black cohosh demonstrated no estrogen-agonistic activity in mammary cells, neither in animal model nor in cell culture, i.e., no gene transcription or cell proliferation was induced. Here we tested for the influence of a standardized isopropanolic extract of black cohosh on an animal model of endometrial cancer. Ectopic growth of the primary tumor as well as the incidence and localization of metastases were examined, partly in the setting of a combination treatment with tamoxifen. In contrast to the endometrial estrogen agonist tamoxifen, black cohosh did not further growth or metastasizing potential of the primary tumor. Absence of detectable supportive or antagonistic effects between both treatments most probable come from the relatively high tamoxifen dose.


PMID: 15110078 [PubMed - indexed for MEDLINE]


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