Black cohosh

Related Terms

• Actaea macrotys, Actaea racemosa L., actee a grappes (French), amerikanisches Wanzenkraut (German), baneberry, BCE, black cohosh roots, black snakeroot, botrophis serpentaria, bugwort, cimicifuga, Cimicifugae racemosae rhizoma, cimicifugawurzelstock (German), cohosh bugbane, ethanolic aqueous extract, herbe au punaise (French), hydroxytyrosol, isoferulic, isopropanolic black cohosh extract, macrotys, Macrotys actaeoides, phytoestrogen, Ranunculaceae (family), rattle root, rattle snakeroot, rattle top, rattle weed, rhizoma actaeae richweed, rhizome of black cohosh, rich weed, schwarze Schlangenwurzel, snakeroot, solvlys, squaw root, squawroot, Thalictrodes racemosa, Traubensilberkerze, Wanzwnkraut (German).
• Note: Do not confuse black cohosh (Cimicifuga racemosa) with blue cohosh (Caulophyllum thalictroides), which contains chemicals that may damage the heart and raise blood pressure. Do not confuse black cohosh (Cimicifuga racemosa) with Cimicifuga foetida, bugbane, fairy candles, or sheng ma; these are species from the same family (Ranunculaceae) with different effects.

Background

• Black cohosh is popular as an alternative to hormonal therapy in the treatment of menopausal (climacteric) symptoms such as hot flashes, mood disturbances, diaphoresis, palpitations, and vaginal dryness. Several studies have reported black cohosh to improve menopausal symptoms for up to six months, although the current evidence is mixed.
• The mechanism of action of black cohosh remains unclear and the effects on estrogen receptors or hormonal levels (if any) are not definitively known. Recent publications suggest that there may be no direct effects on estrogen receptors, although this is an area of active controversy. Safety and efficacy beyond six months have not been proven, although recent reports suggest safety of short-term use, including in women experiencing menopausal symptoms for whom estrogen replacement therapy is contraindicated. Nonetheless, caution is advisable until better-quality safety data are available. Use of black cohosh in high-risk populations (such as in women with a history of breast cancer) should be under the supervision of a licensed healthcare professional.

Evidence

*Key to grades:

A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

For full grading rationale, click here.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy. Consult a healthcare professional immediately if you experience side effects.

Allergies

• Avoid if allergic to black cohosh or other members of the Ranunculaceae (buttercup or crowfoot) family. In nature, black cohosh contains small amounts of salicylic acid (which is found in aspirin), but it is not clear how much (if any) is present in commercially available products. Black cohosh should be used cautiously in people allergic to aspirin or to other salicylates.

Side Effects and Warnings

• Black cohosh is generally well tolerated in recommended doses and has been studied for up to six months. High doses of black cohosh may cause frontal headache, dizziness, perspiration, or visual disturbances. Several side effects have been noted in studies including constipation, intestinal discomfort, loss of bone mass (leading to osteoporosis), irregular or slow heartbeat, low blood pressure, muscle damage, nausea, and vomiting. Dysphoria and "heaviness in the legs" may occur.
• It is not clear if black cohosh is safe in individuals with hormone-sensitive conditions such as breast cancer, uterine cancer, or endometriosis. There is controversy as to whether black cohosh is similar to estrogen in its mechanism, although recent studies suggest that it may not be. The influence of black cohosh on anti-estrogen drugs (like tamoxifen) or hormone replacement therapy is not clear. It is not known if black cohosh possesses the beneficial effects that estrogen is believed to have on bone mass or the potential harmful effects such as increased risk of stroke or hormone-sensitive cancers.
• A few gynecologic organ-related adverse events have been reported including vaginal bleeding and miscarriage; however, the effects of black cohosh in these events are unclear.
• Hepatitis (liver damage) and liver failure has been reported with the use of black cohosh containing products. Liver transplantation has been required in some patients. These reports are concerning, although the cases have been criticized by some as not being adequately substantiated. Nonetheless, patients with liver disease should consult a licensed healthcare professional before using black cohosh.
• Black cohosh should also be used cautiously in patients with a history of blood clots, seizure disorder, or high blood pressure.

Pregnancy and Breastfeeding

• Safety during pregnancy and breastfeeding has not been established. Black cohosh may relax the muscular wall of the uterus and some nurse-midwives in the United States use black cohosh to stimulate labor. Black cohosh may also have hormonal effects and caution is advised during breastfeeding. There is one report of severe multi-organ damage in a child delivered with the aid of both black cohosh and blue cohosh (Caulophyllum thalictroides) who was not breathing at the time of birth. The child survived with permanent brain damage. However, blue cohosh is known to have effects on the heart and blood vessels and may have been responsible for these effects.
• Tinctures may be ill-advised during pregnancy due to potentially high alcohol content.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy.

Interactions with Drugs

• The potential estrogen-like effects of black cohosh remain debated and the active chemical contents of black cohosh have not been clearly identified. Although recent studies suggest no significant effects of black cohosh on estrogen receptors in the body, caution is warranted in people taking both black cohosh and estrogens due to unknown effects. The influence of black cohosh in combination with tamoxifen is not clear in studies and it is not known if tamoxifen counteracts the effects of black cohosh. Drugs like raloxifene may also interact.
• Black cohosh may lower blood pressure and therefore should be used cautiously with other hypotensive agents such as beta-blockers like metoprolol (Lopressor®, Toprol®) or propranolol (Inderal®) and calcium-channel blockers like diltiazem (Cardizem®, Tiazac®) or verapamil (Isoptin®, Calan®). Black cohosh may contain small amounts of salicylic acid and may increase the anti-platelet effects of other agents such as aspirin.
• Black cohosh may alter the way the liver breaks down or metabolizes certain drugs. In theory, due to possible alcohol content in some tinctures of black cohosh, combination with disulfiram (Antabuse®) or metronidazole (Flagyl®) may cause nausea and vomiting.
• Although not well studied in humans, black cohosh may potentially interact with antidepressants, and antihistamines. It may also interact with agents taken for the treatment of cancer and osteoporosis. Other potential interactions include pain relievers, anesthetics, anti-inflammatories, cholesterol-lowering drugs, and anti-seizure drugs.

Interactions with Herbs and Dietary Supplements

• Black cohosh should be used cautiously in people taking herbs with possible hormonal effects. This is a theoretical concern and it is not clear if the amounts of salicylates present in commercial or processed black cohosh products have significant effects in humans.
• Seizures were reported in a woman taking a combination of black cohosh, chaste tree (berries and seeds), and evening primrose oil for four months who also consumed alcohol. The cause of her seizures is not clear.
• Both black cohosh and blue cohosh (Caulophyllum thalictroides) are used by nurse-midwives in the United States to assist birth. There is one report of severe multi-organ damage in a child delivered with the aid of both black cohosh and blue cohosh who was not breathing at the time of birth. The child survived with permanent brain damage. However, blue cohosh is known to have effects on the heart and blood vessels and may have been responsible for these effects. Pennyroyal and black cohosh should not be used together, as there is a possibility of increased toxicity and death.
• Black cohosh may lower blood pressure and therefore interact with other herbs or supplements that also affect blood pressure.
• In theory, black cohosh may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, garlic, and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
• Black cohosh may alter the way the liver breaks down or metabolizes certain herbs and supplements.
• Although not well studied in humans, black cohosh may potentially interact with herbs and supplements with antidepressant, antihistamine, or antioxidant effects. It may also interact with herbs or supplements taken for the treatment of cancer and osteoporosis. Interactions with pain relievers, anesthetics, anti-inflammatories, cholesterol-lowering therapies, and St. John's wort are also possible.

Authors

• This information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Selected References

Natural Standard developed the above evidence-based information based on a systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

1. Antoine C, Liebens F, Carly B, et al. Safety of alternative treatments for menopausal symptoms after breast cancer: a qualitative systematic review. Climacteric 2007;10(1):23-26.
2. Borrelli F, Mascolo N, Russo A, et al. Cimicifuga racemosa: a systematic review of its clinical and pharmacological effects 8^th Annual Symposium on Complementary Health Care 6-8^th December 2001 Exeter, UK. Focus on Alternative and Complementary Therapies. March 2002 7(1):86.
3. Briese V, Stammwitz U, Friede M, et al. Black cohosh with or without St. John's wort for symptom-specific climacteric treatment-Results of a large-scale, controlled, observational study. Maturitas 2007 Aug 20;57(4):405-14.
4. Chung DJ, Kim HY, Park KH, et al. Black cohosh and St. John's wort (GYNO-Plus) for climacteric symptoms. Yonsei Med J 2007 Apr 30;48(2):289-94.
5. Burke BE, Olson RD, Cusack BJ. Randomized, controlled trial of phytoestrogen in the prophylactic treatment of menstrual migraine. Biomed Pharmacother 2002;Aug, 56(6):283-288.
6. Huntley A. The safety of black cohosh (Actaea racemosa, Cimicifuga racemosa). Expert Opin Drug Saf 2004;Nov, 3(6):615-623.
7. Kronenberg F, Fugh-Berman A. Complementary and Alternative Medicine for Menopausal Symptoms: A Review of Randomized, Controlled Trials. Annals of Internal Medicine, 2002;137(10):805-814.
8. Levitsky J, Alli TA, Wisecarver J, et al. Fulminant liver failure associated with the use of black cohosh. Dig Dis Sci. 2005 Mar;50(3):538-9.
9. Liske E, Hanggi W, Henneicke-von Zepelin HH, 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 Womens Health Gend Based Med 2002;11(2):163-174.
10. Mills SY, Jacoby RK, Chacksfield M, et al. Effect of a proprietary herbal medicine on the relief of chronic arthritic pain: a double-blind study. Br J Rheumatol 1996;35(9):874-878.
11. Osmers R, Friede M, Liske E, et al. Efficacy and safety of isopropanolic black cohosh extract for climacteric symptoms. Obstet Gynecol. 2005 May;105(5 Pt 1):1074-83.
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 Jun 20;24(18):2836-41.
13. 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 2007 Apr 1;120(7):1523-8.
14. Rotem C, Kaplan B. Phyto-Female Complex for the relief of hot flushes, night sweats and quality of sleep: randomized, controlled, double-blind pilot study. Gynecol Endocrinol 2007 Feb;23(2):117-22.
15. Walji R, Boon H, Guns E, et al. Black cohosh (Cimicifuga racemosa [L.] Nutt.): safety and efficacy for cancer patients. Support Care Cancer 2007 Aug;15(8):913-21.

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