Actaea racemosa, more widely known as Black Cohosh is native to North America. It is a herbaceous perennial plant that grows in woodlands that produces large leaves. Black Cohosh was formerly named Cimicifuga racemosa. The roots of this herb is commonly used to treat various health conditions such as menstrual dysfunction, menopausal symptoms, hot flashes, among others. In numerous studies, Black cohosh appears to be effective in treating and alleviating menopausal symptoms.
Exactly how Black Cohosh works is still not determined. Previously, it was believed that the herb had estrogen like activity, however, some recent studies have found that contrary to previous knowledge, Black Cohosh does not seem to have estrogen activities, and even possibly as a weak anti-estrogen. [1] Native americans have long used Black cohosh to treat gynecological disorders and other disorders including sore throats, kidney problems, and depression.
Taken for short periods of time, studies have suggested that Black cohosh appears to be safe; however longer term use has been cautioned against. There has been reports of possible liver damage resulting from the use of Black Cohosh. Aside from this, other benefits of Black cohosh includes having a possible application in prevention and treatment of prostate cancer, and possible weight loss benefits.
Black Cohosh Uses and Side Effects
Black Cohosh has long been used for treating various gynecological disorders and menopausal symptoms such as hot flashes and menstrual dysfunction. There are many studies that have been done on Black Cohosh and its uses and effects on management of hot flashes. There are a limited number of studies suggesting no benefits of using Black Cohosh [2, 3], while many other studies citing conclusive evidence of such benefits. One study conducted at the Mayo Clinic and Mayo Foundation in the US had results which suggests that there lacks any evidence that black cohosh reduced hot flashes more than placebo.
This double-blind, randomized, cross-over clinical trial studied the effects of Black Cohosh on hot flashes. 1 capsule containing 20mg of Cimicifuga racemosa (black cohosh) was given to 132 female participants for 4 weeks. During the trial period, scores were assigned by the women to assess the severity of their hot flashes. The study noted minimal side effects of black cohosh. However, their results found no real differences between the placebo and black cohosh groups. Their study failed to find any benefits of using black cohosh to treat hot flashes. [3]
However, there are many other studies that have found evidence suggesting that black cohosh does indeed have benefits in alleviating menopausal symptoms and improving quality of life in post-menopausal women. 122 healthy, post-menopausal Spanish women with elevated body weight, aged between 45 and 59 years took part in a black cohosh study in Spain. The treatment with black cohosh improved the quality of life in the participants. [4] The findings of this study suggests that black cohosh can play an important role in reducing symptoms and help improve the quality of life in post menopausal woman.
Studies have found that while black cohosh extract may not exhibit a benefit on all females experiencing post menopausal symptoms, it does helps treat women with menopausal disorders of at least moderate intensity [5]. The effectiveness of Black cohosh has also been compared to fluoxetine (prozac) in the treatment of women with postmenopausal symptoms. The study of 120 female subjects with menopausal symptoms took part in this study. Comparing the study results, the black cohosh group experienced a greater reduction in hot flushes and night sweats. [6] While black cohosh was more effective at reducing night sweats and hot flashes, fluoxetine was more effective in reducing symptoms of depression.
Black Cohosh Extract on Weight Gain & Cancer
While black cohosh is primarily used to treat post menopausal symptoms, limited studies have also found the herb to have benefits on controlling weight gain, and with some evidence suggesting that it may have uses in preventing and treating prostate cancer.
Effects of black cohosh extract on body weight gain, intra-abdominal fat accumulation, plasma lipids and glucose tolerance in ovariectomized Sprague-Dawley rats. Rachoń D, Vortherms T, Seidlová-Wuttke D, Wuttke W.
Department of Clinical and Experimental Endocrinology, University of Göttingen, Göttingen, Germany.
The objective of this study was to evaluate the effects of dietary black cohosh extract consumption on body weight gain, intra-abdominal fat accumulation, plasma leptin, lipids and glucose tolerance in ovariectomized rats. 27 rats were separated into a black cohosh (6.67g/kg) group and a control group. After a 6 week treatment period, intra abdominal fat was measured, and glucose tolerance test was performed. The results showed that the dietary black cohosh significantly reduced serum lutenizing hormone (LH) levels, the black cohosh treated animals gained less weight, and had less accumulation of abdominal fat. They concluded that treatment with the black cohosh extract helps reduce body weight gain and intra abdominal fat accumulation. [7]
Some studies have also found black cohosh extract to have inhibitory effects on prostate cancer. Studies involving mice have found that treatment with black cohosh extract significantly reduced tumor growth in the mice suggesting the possibility that black cohosh may be efficient in preventing and treating prostate cancer. [8] Other similar studies have found black cohosh extract has an anti-proliferative effect, potently inhibiting the growth of human prostate cancer cells in vitro. [9]
Side Effects of Black Cohosh
Black cohosh is a North American perennial plant that has been used for traditional medicinal purposes by the native Indian population. There are studies that have been done on black cohosh to determine its safety and potential side effects. In a study by the Universities of Exeter and Plymouth in UK, it was stated that black cohosh is a safe herbal therapy for menopausal women taken only for limited period of time. However, the safety and side effects of back cohosh long term use still requires more investigation. [10]
Despite the short term safety statements made in that study, there are some, albeit, rare cases where the use of black cohosh was associated with hepatotoxicity and acute liver failure. One recent study cited 2 cases where the liver problems and hepatitis was related to the usage of preparations containing black cohosh [11]. Another study cited acute liver failure associated with the use of herbal preparations containing black cohosh. [12]
Regulatory agencies in Australia, Canada, and the European Union have released statements regarding the "potential association" between black cohosh and hepatotoxicity. The United States Pharmacopeia made a review of black cohosh case reports of hepatotoxicity, and based on the results of their safety review, the committee determined that black cohosh products should be labeled to include a cautionary statement, which marks a change from their 2002 decision, which required no such cautionary statements. [13]
As stated in these studies, the acute liver failure cases are rare, but the safety concerns merit caution for the end user. Aside from these potential severe adverse side effects, some other side effects of black cohosh include headaches, nausea, dizziness, upset stomach, and a heavy feeling in the legs. While short term use is generally regarded as safe [10], long term use should be avoided.
1. J Steroid Biochem Mol Biol. 2005 Nov;97(3):271-7. Epub 2005 Sep 26.
No estrogen-like effects of an isopropanolic extract of Rhizoma Cimicifugae racemosae on uterus and vena cava of rats after 17 day treatment.
Kretzschmar G, Nisslein T, Zierau O, Vollmer G.
Institut für Zoologie, Technische Universität Dresden, Germany. georg.kretzschmar@web.de
2. Menopause. 2008 Dec 4
A randomized placebo-controlled trial on the effectiveness of an herbal formula to alleviate menopausal vasomotor symptoms.
van der Sluijs CP, Bensoussan A, Chang S, Baber R.
From 1CompleMED, Centre for Complementary Medicine Research, University of Western Sydney, Sydney, Australia; 2Department of Obstetrics and Gynaecology, University of Sydney, Sydney, Australia; and 3Menopause Clinic, Royal North Shore Hospital, Sydney, Australia.
3. J Clin Oncol. 2006 Jun 20;24(18):2836-41.
Phase III double-blind, randomized, placebo-controlled crossover trial of black cohosh in the management of hot flashes: NCCTG Trial N01CC1.
Pockaj BA, Gallagher JG, Loprinzi CL, Stella PJ, Barton DL, Sloan JA, Lavasseur BI, Rao RM, Fitch TR, Rowland KM, Novotny PJ, Flynn PJ, Richelson E, Fauq AH.
Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
4. Gynecol Endocrinol. 2009 Jan;25(1):21-6.
Cimicifuga racemosa treatment and health related quality of life in post-menopausal Spanish women.
Mollá MD, García-Sánchez Y, Sarri AR, Pérez-lópez FR.
Gynaecology and Reproduction Medicine Service, University Hospital La Fe, Valencia, Spain.
5. Maturitas. 2005 Aug 16;51(4):397-404. Epub 2004 Dec 10.
Cimicifuga racemosa dried ethanolic extract in menopausal disorders: a double-blind placebo-controlled clinical trial.
Frei-Kleiner S, Schaffner W, Rahlfs VW, Bodmer Ch, Birkhäuser M.
Institute of Pharmaceutical Biology, University of Basel, Switzerland. susanne@frei-kleiner.ch
6. Adv Ther. 2007 Mar-Apr;24(2):448-61.
Black cohosh and fluoxetine in the treatment of postmenopausal symptoms: a prospective, randomized trial.
Oktem M, Eroglu D, Karahan HB, Taskintuna N, Kuscu E, Zeyneloglu HB.
Department of Obstetrics and Gynecology, Baskent University, School of Medicine, Maltepe, Ankara, Turkey. mesutoktem@hotmail.com
7. Maturitas. 2008 Jul-Aug;60(3-4):209-15. Epub 2008 Aug 8.
Effects of black cohosh extract on body weight gain, intra-abdominal fat accumulation, plasma lipids and glucose tolerance in ovariectomized Sprague-Dawley rats.
Rachoń D, Vortherms T, Seidlová-Wuttke D, Wuttke W.
Department of Clinical and Experimental Endocrinology, University of Göttingen, Göttingen, Germany.
8. Planta Med. 2006 May;72(6):521-6.
Inhibitory effects of a black cohosh (Cimicifuga racemosa) extract on prostate cancer.
Seidlová-Wuttke D, Thelen P, Wuttke W.
Department of Clinical and Experimental Endocrinology, University of Göttingen, Germany. ufkendo@med.uni-goettingen.de
9. Phytomedicine. 2005 Mar;12(3):178-82
Cimicifuga racemosa extract BNO 1055 inhibits proliferation of the human prostate cancer cell line LNCaP.
Jarry H, Thelen P, Christoffel V, Spengler B, Wuttke W.
Department of Obstetrics and Gynecology, University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany. hubjarry@med.uni-goettingen.de
10. Expert Opin Drug Saf. 2004 Nov;3(6):615-23.
The safety of black cohosh (Actaea racemosa, Cimicifuga racemosa).
Huntley A.
Universities of Exeter and Plymouth, Complementary Medicine, Peninsula Medical School, 25 Victoria Park Road, Exeter, EX2 4NT, UK. alyson.huntley@pms.ac.uk
11. Eur J Gastroenterol Hepatol. 2009 Apr 28. [Epub ahead of print]
Severe hepatitis associated with the use of black cohosh: a report of two cases and an advice for caution.
Pierard S, Coche JC, Lanthier P, Dekoninck X, Lanthier N, Rahier J, Geubel AP.
Departments of aInternal Medicine bGastroenterology, Clinique Saint Pierre, Ottignies cDepartment of Gastroenterology, Clinique St Joseph, Mons Departments of dPathology eGastroenterology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Bruxelles, Belgium.
12. Med J Aust. 2003 Oct 6;179(7):390-1.
Med J Aust. 2004 Jun 7;180(11):598-9; author reply 599-600.
Acute liver failure associated with the use of herbal preparations containing black cohosh.
13. Menopause. 2008 Jul-Aug;15(4 Pt 1):628-38.
United States Pharmacopeia review of the black cohosh case reports of hepatotoxicity.
Mahady GB, Low Dog T, Barrett ML, Chavez ML, Gardiner P, Ko R, Marles RJ, Pellicore LS, Giancaspro GI, Sarma DN.
USP Dietary Supplements Information Expert Committee (DSI EC), US Pharmacopeia, Rockville, MD, USA.
