Black Cohosh

Purported Benefits, Side Effects & More

Black Cohosh

Purported Benefits, Side Effects & More
Black Cohosh

Common Names

  • Black snakeroot
  • Rattlesnake root
  • Squawroot

For Patients & Caregivers

Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.

What is it?

Black cohosh is a plant used in herbal medicine. The root of this plant is used to treat menstrual (monthly period) cramps and symptoms you may get during menopause (permanent end to your menstrual cycle), such as hot flashes.

You can take black cohosh supplements as tablets, capsules, or liquid extracts.

What are the potential uses and benefits?

Black cohosh is used to:

  • Treat menstrual cramps and pain
  • Treat symptoms of menopause (permanent end of menstrual cycles) such as hot flashes
  • Treat premenstrual (one or two weeks before period) symptoms such as bloating, mood swings, and irritability

Black cohosh also has other uses that haven’t been studied by doctors to see if they work.

Talk with your healthcare provider before taking black cohosh supplements. Herbal supplements can interact with some medications and affect how they work. For more information, read the “What else do I need to know?” section of this resource.

What are the side effects?

Side effects of using high amounts of black cohosh may include:

  • Stomach upset
  • Rash
  • Dizziness
  • Nausea (feeling like you’re going to throw up)
  • Vomiting (throwing up)

Although rare, a few cases of abnormal liver function and liver damage were also reported after taking black cohosh.

What else do I need to know?
  • Talk to your healthcare provider if you have a liver disorder. Black cohosh can worsen your condition.  
  • Talk to your healthcare provider if you have breast cancer, or if you’re at risk of breast cancer. Whether black cohosh is safe or not is unclear.

For Healthcare Professionals

Brand Name
Remifemin®, Menofem®, Klimadynon®
Scientific Name
Cimicifuga racemosa
Clinical Summary

Obtained from the root of the plant, black cohosh is used as a dietary supplement to relieve symptoms of menopause and dysmenorrhea. Preliminary data suggest it has antiosteoporotic effects (8) and enhances bone formation (9). Black cohosh by itself (2) (3) or in combination with other herbs (4) (5) may be effective for menopausal symptoms, although data are conflicting (6) (31) (32) (36) (45) and an older meta analysis cited insufficient evidence to support its use (40). However, a more recent meta-analysis found isopropanolic black cohosh extract, an herbal medicinal product widely used in the EU as nonhormonal therapy, is comparable to low-dose transdermal estradiol or tibolone with a better benefit-risk profile than tibolone (62).

Investigations of black cohosh for hot flashes due to breast cancer treatment also yielded mixed results (10) (11) (12), but supplementation may be effective for menopausal syndrome induced by luteinizing hormone-releasing hormone analogue (57). In other studies, black cohosh did not enhance bone density, improve menopausal symptoms, nor improve 10-year risk of coronary heart disease in early postmenopausal women (37), although it has been reported to improve sleep (53).

Preclinical data suggest black cohosh may decrease proliferation of prostate cancer cells (14) and induce an apoptotic response in liver cells (21), but it also increased incidence of metastatic disease in mice (16). Whether it has similar effects in breast cancer patients is not clear, and a retrospective observational study of breast cancer patients found that isopropanolic black cohosh extract enhanced disease-free survival (15).

Concomitant use of black cohosh with prescription medications has been associated with adverse drug reactions, most commonly involving abnormal hepatic function, hepatitis or hepatotoxicity (58). Black cohosh should not be confused with blue cohosh, which has a different medicinal profile. It is also not clear whether or not black cohosh acts as a phytoestrogen. Patients with breast cancer or at risk of breast cancer should consult with their physicians before taking it.

Purported Uses and Benefits
  • Dysmenorrhea
  • Menopausal symptoms
  • Premenstrual syndrome
Mechanism of Action

Black cohosh relieves menopausal symptoms likely by mimicking neurostransmitters: dopaminergic, noradrenergic, serotoninergic and GABAergic effects have been demonstrated (49). It was believed to have estrogenic effects due to its ability to relieve menopausal symptoms in women (40), but studies show it has no effect on LH, FSH, prolactin, or estradiol levels (24). A black cohosh extract had antiproliferative and antiestrogenic effects in ER-negative cells, which suggests effects are mediated via an estrogen-independent pathway (25), possibly through HER-2 signaling (26).

In other studies, black cohosh repressed cyclin D1 and ID3 expression and inhibited proliferation of HepG2 p53-positive liver cells (43). In prostate cancer cells, antiproliferative effects occurred via impaired equilibrative nucleoside transporter activity, resulting in hindered nucleoside uptake (50). Black cohosh also induced apoptosis and suppressed estradiol-induced cell proliferation in human endometrial adenocarcinoma cells (55).

Hepatotoxicity is a major concern with black cohosh use. Evaluation of liver biopsies from two patients who took black cohosh supplements showed pathological injury identical to toxic necrosis, seen during autoimmune hepatitis (51).

  • After reviewing 30 independent cases of hepatoxicity associated with black cohosh intake, the United States Pharmacopeia’s Botanical Expert Committee decided that black cohosh products should include a statement of caution concerning their use (28).
  • A recent survey reported poor quality control of several black cohosh products (44).
  • Pregnant women should avoid black cohosh because it has the potential to act as an abortifacient (60).
Adverse Reactions
  • GI upset, rashes, dizziness, headaches, nausea, and vomiting with higher than normal doses (27)

Case reports

  • Hepatotoxicity: Following use of black cohosh (18) (20) (33) (34) (47).
  • Liver injury resembling autoimmune hepatitis: Two cases in which both patients responded to corticosteroid treatment (35).
  • Transient autoimmune hepatitis: As well as coagulation activation and fluid retention in a patient likely triggered by use of black cohosh (38). Although lower leg edema is not uncommon in women suffering from climacteric and menopausal symptoms, black cohosh-induced fluid retention and coagulation activation should be considered, especially if thrombosis has been excluded.
  • Acute liver injury: In a 40-year-old woman with concomitant use of black cohosh and Thuja occidentalis. However, it is unclear to what extent each botanical or the combination contributed to this event (63).
  • Bradycardia: Observed in a woman following use of black cohosh (41).
  • Orobuccolingual dyskinesia: Involving speech interference, tongue-biting, and eating difficulties in a 46-year-old woman while taking an herbal supplement containing black cohosh and ginseng (48).
  • Severe hyponatremia: In a 39-year-old woman following several doses of black cohosh to induce/augment labor for home birth. She later underwent cesarean delivery, and sodium levels returned to normal after treatment with hypertonic saline (59).
  • Acute onset mania: Associated with black cohosh, likely due to its psychopharmacological activities on serotonergic and dopaminergic receptors (61).
Herb-Drug Interactions

Tamoxifen: Black cohosh may interfere with the action of tamoxifen (42). Clinical relevance is not known.
Chemotherapy drugs: Black cohosh may increase toxicity of doxorubicin and docetaxel (13). Clinical significance has yet to be determined.
CYP450 3A4: Black cohosh may interact with drugs metabolized by the CYP3A4 enzyme (17). Clinical significance has yet to be determined.
Simvastatin: Black cohosh and the isolated compound actein have synergistic effects with simvastatin that may enhance activity but also increase side effects (56).

Dosage (OneMSK Only)
  1. Anon. Remifemin: A Plant-based Gynecological Agent. Germany: Schaper & Brümmer; 1997.
  2. Liske E, et al. Physiological investigation of a unique extract of black cohosh (Cimicifugae racemosae rhizoma): a 6-month clinical study demonstrates no systemic estrogenic effect. J Women Health Gend Based Med 2002;11:163-74.
  3. Oktem M, Eroglu D, Karahan HB, et al. Black cohosh and fluoxetine in the treatment of postmenopausal symptoms: a prospective, randomized trial. Adv Ther. Mar-Apr 2007;24(2):448-461.
  4. Uebelhack R, Blohmer JU, Graubaum HJ, Busch R, Gruenwald J, Wernecke KD. Black cohosh and St. John’s wort for climacteric complaints: a randomized trial. Obstet Gynecol 2006;107(2):247-55.
  5. Briese V, Stammwitz U, Friede M, Henneicke-von Zepelin HH. Black cohosh with or without St. John’s wort for symptom-specific climacteric treatment—results of a large-scale, controlled, observational study. Maturitas. Aug 20 2007;57(4):405-414.
  6. Newton KM, Reed SD, LaCroix AZ, et al. Treatment of vasomotor symptoms of menopause with black cohosh, mutibotanicals, soy, hormone therapy, or placebo. Ann Intern Med 2006;145:869-879.
  7. Bai W, Henneicke-von Zepelin HH, Wang S, et al. Efficacy and tolerability of a medicinal product containing an isopropanolic black cohosh extract in Chinese women with menopausal symptoms: a randomized, double blind, parallel-controlled study versus tibolone. Maturitas. Sep 20 2007;58(1):31-41.
  8. Wuttke W, Gorkow C, Seidlova-Wuttke D. Effects of black cohosh (Cimicifuga racemosa) on bone turnover, vaginal mucosa, and various blood parameters in postmenopausal women: a double-blind, placebo-controlled, and conjugated estrogens-controlled study. Menopause 2006; 13(2):185-96.
  9. Chan BY, Lau KS, Jiang B, Kennelly EJ, Kronenberg F, Kung AW. Ethanolic extract of Actaea racemosa (black cohosh) potentiates bone nodule formation in MC3T3-E1 preosteoblast cells. Bone. 2008 Sep;43(3):567-73.
  10. Hernandez Munoz G, Pluchino S. Cimicifuga racemosa for the treatment of hot flushes in women surviving breast cancer. Maturitas. 2003 Mar 14;44 Suppl 1:S59-65.
  11. Jacobson JS, Troxel AB, Evans J, et al. Randomized trial of black cohosh for the treatment of hot flashes among women with a history of breast cancer. J Clin Oncol 2001;19:2739-45.
  12. Pockaj BA, Gallagher JG, Loprinzi CL, et al. Phase III Double-Blind, Randomized, Placebo-Controlled Crossover Trial of Black Cohosh in the Management of Hot Flashes: NCCTG Trial N01CC1. J Clin Oncol 2006;24(18):2836-41.
  13. Rockwell S, Liu Y, Higgins SA. Alteration of the effects of cancer therapy agents on breast cancer cells by the herbal medicine black cohosh. Breast Cancer Res Treat 2005;90(3):233-9.
  14. Jarry H, Stromeier S, Wuttke W, Nahrstedt A. Petasiphenone, a phenol isolated from Cimicifuga racemosa, in vitro inhibits proliferation of the human prostate cancer cell line LNCaP. Planta Med. Feb 2007;73(2):184-187.
  15. Zepelin HH, Meden H, Kostev K, et al. Isopropanolic black cohosh extract and recurrence-free survival after breast cancer. Int J Clin Pharmacol Ther. Mar 2007;45(3):143-154.
  16. Davis VL, Jayo MJ, Ho A, et al. Black cohosh increases metastatic mammary cancer in transgenic mice expressing c-erbB2. Cancer Res. 2008 Oct 15;68(20):8377-83.
  17. Tsukamoto S, Aburatani M, Ohta T. Isolation of CYP3A4 Inhibitors from the Black Cohosh (Cimicifuga racemosa). Evid Based Complement Alternat Med. Jun 2005;2(2):223-226.
  18. Cohen SM, O’Connor AM, Hart J, et al. Autoimmune hepatitis associated with the use of black cohosh: a case study. Menopause 2004;11(5):575-77.
  19. Levitsky J, Alli TA, Wisecarver J, et al. Fulminant liver failure associated with the use of black cohosh. Dig Dis Sci. Mar 2005;50(3):538-539.
  20. Lontos S, Jones RM, Angus PW, Gow PJ. Acute liver failure associated with the use of herbal preparations containing black cohosh. MJA 2003;179(7): 390-91.
  21. Lude S, Torok M, Dieterle S, et al. Hepatic effects of Cimicifuga racemosa extract in vivo and in vitro. Cell Mol Life Sci. Nov 2007;64(21):2848-2857.
  22. Newall C. Herbal Medicines, A Guide for Health Care Professionals. London: Pharmaceutical Press; 1996.
  23. Zierau O, Bodinet C, Kolba S, et al. Antiestrogenic activities of Cimicifuga racemosa extracts. J Steroid Biochem Mol Biol 2002;80:125-30.
  24. Liske E. Therapeutic efficacy and safety of Cimicifuga racemosa for gynecologic disorders. Adv Ther. Jan-Feb 1998;15(1):45-53.
  25. Garita-Hernandez M, Calzado MA, Caballero FJ, et al. The growth inhibitory activity of the Cimicifuga racemosa extract Ze450 is mediated through estrogen and progesterone receptors-independent pathways. Planta Med 2006:72(4):317-23.
  26. Einbond LS, Wen-Cai Y, He K, et al. Growth inhibitory activity of extracts and compounds from Cimicifuga species on human breast cancer cells. Phytomedicine. Jun 2008;15(6-7):504-511.
  27. Low Dog T, Powell KL, Weisman SM. Critical evaluation of the safety of Cimicifuga racemosa in menopause symptom relief. Menopause. Jul-Aug 2003;10(4):299-313.
  28. Mahady GB, Dog TL, Barrett ML, et al. United States Pharmacopeia review of the black cohosh case reports of hepatotoxicity. Menopause. Mar 12 2008.
  29. Rebbeck TR, Troxel AB, Norman S, et al. A retrospective case-control study of the use of hormone-related supplements and association with breast cancer. Int J Cancer. Apr 1 2007;120(7):1523-1528.
  30. Duker EM, Kopanski L, Jarry H, Wuttke W. Effects of extracts of Cimicifuga racemosa (Remifemin) on gonadotropin release in menopausal women and ovariectomized rats. Planta Med 1991;57:420.
  31. Reed SD, Newton KM, LaCroix AZ, et al. Vaginal, endometrial, and reproductive hormone findings: randomized, placebo-controlled trial of black cohosh, multibotanical herbs, and dietary soy for vasomotor symptoms: the Herbal Alternatives for Menopause (HALT) Study. Menopause. 2008 Jan-Feb;15(1):51-8.
  32. Geller SE, Shulman LP, van Breemen RB, et al. Safety and efficacy of black cohosh and red clover for the management of vasomotor symptoms: a randomized controlled trial. Menopause 2009 Nov-Dec;16(6):1156-66.
  33. Pierard S, Coche JC, Lanthier P, et al. Severe hepatitis associated with the use of black cohosh: a report of two cases and an advice for caution. Eur J Gastroenterol Hepatol. 2009 Aug;21(8):941-5.
  34. Vannacci A, Lapi F, Gallo E, et al. A case of hepatitis associated with long-term use of Cimicifuga racemosa. Altern Ther Health Med. 2009 May-Jun;15(3):62-3.
  35. Guzman G, Kallwitz ER, Wojewoda C, et al. Liver Injury with Features Mimicking Autoimmune Hepatitis following the Use of Black Cohosh. Case Report Med. 2009;2009:918156.
  36. Shams T, Setia MS, Hemmings R, et al. Efficacy of black cohosh-containing preparations on menopausal symptoms: a meta-analysis.  Altern Ther Health Med. 2010 Jan-Feb;16(1):36-44.
  37. Bebenek M, Kemmler W, von Stengel S, Engelke K, Kalender WA. Effect of exercise and Cimicifuga racemosa (CR BNO 1055) on bone mineral density, 10-year coronary heart disease risk, and menopausal complaints: the randomized controlled Training and Cimicifuga racemosa Erlangen (TRACE) study. Menopause. 2010 Jul;17(4):791-800.
  38. Zimmermann R, Witte A, Voll RE, Strobel J, Frieser M. Coagulation activation and fluid retention associated with the use of black cohosh: a case study. Climacteric. 2010 Apr;13(2):187-91.
  39. Naser B, Schnitker J, Minkin MJ, et al. Suspected black cohosh hepatotoxicity: no evidence by meta-analysis of randomized controlled clinical trials for isopropanolic black cohosh extract. Menopause. 2011 Apr;18(4):366-75.
  40. Leach MJ, Moore V. Black cohosh (Cimicifuga spp.) for menopausal symptoms. Cochrane Database Syst Rev. 2012 Sep 12;9:CD007244.
  41. McKenzie SC, Rahman A.  Bradycardia in a patient taking black cohosh. Med J Aust. 2010 Oct 18;193(8):479-81.
  42. Li J, Gödecke T, Chen SN, et al. In vitro metabolic interactions between black cohosh (Cimicifuga racemosa) and tamoxifen via inhibition of cytochromes P450 2D6 and 3A4. Xenobiotica. 2011 Aug 9;10.3109/00498254.2011.603385.
  43. Einbond LS, Soffritti M, Esposti DD, et al. Pharmacological mechanisms of black cohosh in Sprague-Dawley rats. Fitoterapia. 2012 Apr;83(3):461-8.
  44. Teschke R, Schwarzenboeck A, Schmidt-Taenzer W, Wolff A, Hennermann KH. Herb induced liver injury presumably caused by black cohosh: a survey of initially purported cases and herbal quality specifications. Ann Hepatol. 2011 Jul-Sep;10(3):249-59.
  45. Tanmahasamut P, Vichinsartvichai P, Rattanachaiyanont M, Techatraisak K, Dangrat C, Sardod P. Cimicifuga racemosa extract for relieving menopausal symptoms: a randomized controlled trial. Climacteric. 2014 Sep 22:1-7.
  46. Moser C, Vickers SP, Brammer R, Cheetham SC, Drewe J. Antidiabetic effects of the Cimicifuga racemosa extract Ze 450 in vitro and in vivo in ob/ob mice.Phytomedicine. 2014 Sep 25;21(11):1382-9.
  47. Lim TY, Considine A, Quaglia A, Shawcross DL. Subacute liver failure secondary to black cohosh leading to liver transplantation. BMJ Case Rep. 2013 Jul 5;2013.
  48. Sen A.Orobuccolingual dyskinesia after long-term use of black cohosh and ginseng. J Neuropsychiatry Clin Neurosci. 2013 Fall;25(4):E50.
  49. Wuttke W, Jarry H, Haunschild J, Stecher G, Schuh M, Seidlova-Wuttke D.The non-estrogenic alternative for the treatment of climacteric complaints: Black cohosh (Cimicifuga or Actaea racemosa). J Steroid Biochem Mol Biol. 2014 Jan;139:302-10.
  50. Dueregger A, Guggenberger F, Barthelmes J, et al. Attenuation of nucleoside and anti-cancer nucleoside analog drug uptake in prostate cancer cells by Cimicifuga racemosa extract BNO-1055. Phytomedicine. 2013 Nov 15;20(14):1306-14.
  51. Enbom ET, Le MD, Oesterich L, Rutgers J, French SW. Mechanism of hepatotoxicity due to black cohosh (Cimicifuga racemosa): histological, immunohistochemical and electron microscopy analysis of two liver biopsies with clinical correlation. Exp Mol Pathol. 2014 Jun;96(3):279-83.
  52. Cimicifuga racemosa. Altern Med Rev. 2003 May;8(2):186-9.
  53. Jiang K, Jin Y, Huang L, et al. Black cohosh improves objective sleep in postmenopausal women with sleep disturbance. Climacteric. 2015;18(4):559-67.
  54. Da YM, Niu KY, Liu SY, et al. Does Cimicifuga racemosa have the effects like estrogen on the sublingual gland in ovariectomized rats?. 2017 Mar 14;50(1):11.
  55. Dai X, Liu J, Nian Y, Qiu MH, Luo Y, Zhang J. A novel cycloartane triterpenoid from Cimicifuga induces apoptotic and autophagic cell death in human colon cancer HT-29 cells. Oncol Rep. 2017 Apr;37(4):2079-2086.
  56. Einbond LS, Soffritti M, Esposti DD, et al. A transcriptomic analysis of black cohosh: Actein alters cholesterol biosynthesis pathways and synergizes with simvastatin. Food Chem Toxicol. 2018 Oct;120:356-366.
  57. Wang C, Huang Q, Liang CL, et al. Effect of Cimicifuga racemosa on menopausal syndrome caused by LHRH-a in breast cancer. J Ethnopharmacol. 2019 Jun 28;238:111840.
  58. Hoban CL, Byard RW, Musgrave IF. Analysis of spontaneous adverse drug reactions to echinacea, valerian, black cohosh and ginkgo in Australia from 2000 to 2015. J Integr Med. 2019 Sep;17(5):338-343.
  59. Blitz MJ, Smith-Levitin M, Rochelson B. Severe Hyponatremia Associated with Use of Black Cohosh during Prolonged Labor and Unsuccessful Home Birth. AJP Rep. 2016 Mar;6(1):e121-4.
  60. Bernstein N, Akram M, Yaniv-Bachrach Z, Daniyal M. Is it safe to consume traditional medicinal plants during pregnancy? Phytother Res. 2020 Nov 8. doi: 10.1002/ptr.6935.
  61. Yalçın M, Oğuz A, Beştepe EE, Sağlam NGU, Ergelen M. Black cohosh associated mania in a patient with unipolar depression. Int J Psychiatry Med. 2021 Mar;56(2):67-72.
  62. Castelo-Branco C, Gambacciani M, Cano A, et al. Review & meta-analysis: isopropanolic black cohosh extract iCR for menopausal symptoms - an update on the evidence. Climacteric. Apr 2021;24(2):109-119.
  63. Patel R, Alavi F, Ortega S, et al. Herb-Induced Liver Injury by Cimicifuga racemosa and Thuja occidentalis Herbal Medications for Fertility. Case Rep Gastrointest Med. 2021;2021:8858310.
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