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Other common name(s):
black snakeroot, bugbane, bugwort, Remifemin®
Scientific/medical name(s):
Cimicifuga racemosa
Description
Black cohosh is a perennial woodland plant of the eastern
United States and Canada that grows from 4 to 8 feet tall and has
feathery white flowers. The root is used in herbal remedies.
Overview
There is inconsistent evidence regarding whether black cohosh
is effective in relieving menopausal symptoms for women in general. Its
safety and effectiveness for women with menopausal symptoms caused by
treatment of breast cancer is also not clear. Available scientific
evidence does not support claims that black cohosh is effective in
treating cancer. Some studies suggest in might interfere with some
drugs used in chemotherapy. The safety of long-term use is not known.
Serious side effects are rare but have been reported.
How is it promoted for use?
Black cohosh is often referred to as a "woman's remedy"
because it is used mainly to relieve premenstrual problems, menstrual
cramps, and symptoms of menopause such as hot flashes. Commission E
(Germany's regulatory agency for herbs) has approved black cohosh for
these symptoms. Black cohosh is also a source of vitamin A and
pantothenic acid.
In the past, the helpful effects of black cohosh were thought to be due
to chemicals in the plant that resemble and mimic the effects of the
female hormone called estrogen. However, the strength of the plant's
estrogen-like effects has been disputed, and the exact way black cohosh
works in the body is not well understood.
Because some cancers such as breast and endometrial cancer are
stimulated by estrogen, some herbalists state that black cohosh may be
dangerous for people who have cancer. But another view holds that since
the herb does not actually contain estrogen, it is safe for cancer
patients. Some promoters of black cohosh state that the herb reduces
the risk of breast and prostate cancer, although available scientific
evidence does not support these claims.
Other conditions that black cohosh has been used to treat include pain
relief before, during and after childbirth; breast pain; ovarian pain;
and uterine pain. Other reported uses of black cohosh include arthritis
pain relief, lowering blood pressure, sedation, treatment of bronchial
infections, spasms associated with "whooping cough," and diarrhea.
What does it involve?
Black cohosh is the main ingredient in an over-the-counter
German menopausal remedy called Remifemin®.
Black cohosh can be found in several different forms including
capsules, solutions, tablets, and tinctures. There is no standardized
treatment plan for the use of the herb. The typical dose suggested is
20 to 40 milligrams (mg) of Remifemin® twice
daily or 40 to
200 mg of dried root powder.
What is the history behind it?
Cohosh is a Native American word that means "knobby rough
roots," which describes the appearance of the plant's roots. Native
Americans used black cohosh to treat uterine disorders such as
menstrual and menopausal symptoms, as well as other ailments, such as
diarrhea, sore throat, arthritis, and general weakness. The herb has
been approved in Germany for the same purposes for more than 50 years
and is commonly prescribed in other European countries.
What is the evidence?
There is inconsistent evidence of effectiveness from clinical
trials. Some studies report that black cohosh relieves menopausal
symptoms while others do not. Some of the disagreement may be due to
differences in the herbal products tested. A 2005 study of 304 women
found that compared to a placebo, black cohosh helped symptoms of
menopause. It seemed more effective for women whose symptoms have begun
recently than for those who had been postmenopausal for a longer time.
On the other hand, a 2006 study of 351 women found that menopause
symptoms were helped by hormone therapy but not by black cohosh (either
alone or along with other herbs). The North American Menopause Society
recommends considering black cohosh as one of the non-prescription
remedies for mild menopausal symptoms, but points out that the safety
of this herb for women with breast cancer remains uncertain.
A smaller study of 21 women, 13 of whom had breast cancer, also
reported less trouble with sleeping, less fatigue, and less abnormal
sweating after women started taking black cohosh, although this study
did not use a placebo control group. This means that the effects could
have been due to an expectation response ("placebo effect").
A 2001 study of black cohosh and an inactive placebo for breast cancer
survivors found no difference in severity or number of hot flashes,
although there was a slight reduction in sweating. About 2/3 of these
patients were also taking tamoxifen. Two years later, another study of
women with breast cancer being treated with tamoxifen found that hot
flashes were less severe and occurred less often in women taking black
cohosh. However, a 2006 study of 132 cancer survivors found no effect
on hot flashes.
Are there any possible problems
or complications?
This product is sold as a dietary supplement in the
United States. Unlike drugs (which must be tested before being allowed
to be sold), the companies that make supplements are not required to
prove to the Food and Drug Administration that their supplements are
safe or effective, as long as they don't claim the supplements can
prevent, treat, or cure any specific disease.
Some such products may not contain the amount of the herb or
substance that is written on the label, and some may include other
substances (contaminants). Actual amounts per dose may vary between
brands or even between different batches of the same brand.
Most such supplements have not been tested to find out if they
interact with medicines, foods, or other herbs and supplements. Even
though some reports of interactions and harmful effects may be
published, full studies of interactions and effects are not often
available. Because of these limitations, any information on ill effects
and interactions below should be considered incomplete.
Serious reactions to moderate doses of black cohosh are very uncommon.
Common side effects include upset stomach, nausea, and vomiting. A very
high dose may cause slow heart rate, uterine contractions (cramps),
headache, dizziness, tremors, joint pain, and light-headedness. There
have been a few reports of serious liver disease among women who had
recently started using black cohosh. For this reason, some doctors
suggest that people who already have liver problems should not use this
supplement.
Some doctors are concerned that taking black cohosh might affect how
mainstream cancer treatments work. There is some disagreement among
studies of cancer cells grown in laboratory dishes. There seems to be
no impact of black cohosh on the effects of radiation in these cells,
but this herb seems to make some chemotherapy drugs less effective and
others more effective. Some studies found black cohosh may reduce
growth of breast cancer cells in laboratory dishes, but another study
suggests that it can increase spread of breast cancer in mice. Because
of these conflicts and until more is known about this issue, many
oncologists recommend a cautious approach and suggest delaying use of
black cohosh until treatment is over.
Allergic reactions are possible but rarely reported. Those who are
allergic to other members of the buttercup family may be more likely to
react to black cohosh. The herb also contains small amounts of
salicylic acid, and should be used with caution by those allergic to
aspirin.
The German "Commission E" recommends the herb not be taken for more
than 6 months in a row. It should be used with caution in people with
high blood pressure and those taking high blood pressure medications.
Women who are thinking about any form of hormone replacement therapy
should consult their doctors before taking black cohosh. Women who are
pregnant or breast-feeding should not use this herb.
Additional Resources
More Information From Your
American Cancer Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be ordered
from our toll-free number (1-800-ACS-2345).
References
Cohen SM, O'Connor AM, Hart J, Merel NH, Te HS. Autoimmune
hepatitis associated with the use of black cohosh: a case study. Menopause.
2004;11:575-577.
Davis V, et al. Effects of black cohosh on mammary tumor
development and progression in MMTV-neu transgenic mice. Abstract.
Proceedings of the AACR, Vol 44, 2nd ed., July 2003.
Dog TL. Powell KL. Weisman SM. Critical evaluation of the
safety of Cimicifuga racemosa in menopause symptom relief. Menopause.
2003;10:299-313.
Hernandez Munoz G, Pluchino S. Cimicifuga racemosa for the
treatment of hot flushes in women surviving breast cancer. Maturitas. 2003;44,
Suppl 1:S59-65.
Jacobson JS, 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;19:2739-2745.
Lynch CR. Folkers ME. Hutson WR. Fulminant hepatic failure
associated with the use of black cohosh: a case report. Liver Transplantation.2006;
12:989-992.
Memorial Sloan-Kettering Cancer Center. Black cohosh.
Available at:
http://www.mskcc.org/mskcc/html/11571.cfm?RecordID=405&tab=HC.
Accessed April 6, 2007.
MD Anderson Cancer Center. Black cohosh. Available at:
http://www.mdanderson.org/departments/cimer/display.cfm?id=454642F6-FA6F-4259-9CC981E93779D461&method=displayFull&pn=6EB86A59-EBD9-11D4-810100508B603A14.
Accessed April 6, 2007.
Neff, MJ. NAMS releases position statement on the treatment of
vasomotor symptoms associated with menopause. American Family Physician.
2004;70:393-394, 396, 399.
Newton KM, Reed SD, LaCroix AZ, et al. Treatment of vasomotor
symptoms of menopause with black cohosh, multibotanicals, soy, hormone
therapy, or placebo: a randomized trial. Annals of Internal Medicine.
2006;145:869-879.
Osmers R, Friede M, Liske E, et al. Efficacy and safety of
isopropanolic black cohosh extract for climacteric symptoms. Obstetrics & Gynecology.
2005;105:1074-1083.
Pockaj BA, Gallagher JG, Loprinzi CI, et al. Phase III
double-blind, randomized, placebo-controlled crossover trial of black
cohosh in the management of hot flashes: NCCTG Trial N01CC1. Journal of Clinical Oncology.
2006; 24:2836-2841.
Pockaj BA, Loprinzi CL, Sloan JA. et al. Pilot evaluation of
black cohosh for the treatment of hot flashes in women. Cancer Investigation.
2004;22:515-521.
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 Research & Treatment. 2005; 90:233-239.
Stoll W, et al. Phytopharmacon influences atrophic vaginal
epithelium. Double-blind study: Cimicifuga vs. estrogenic substances. Therapeuticum.
1987;1:23.
The North American Menopause Society. Treatment of
menopause-associated vasomotor symptoms: position statement of The
North American Menopause Society. Menopause. 2004;
Jan-Feb;11(1):11-33.
Wuttke W, Seidlova-Wuttke D, Gorkow C. The Cimicifuga
preparation BNO 1055 vs conjugated estrogens in a double-blind
placebo-controlled study: effects on menopause symptoms and bone
markers. Maturitas. 2003;44(Suppl 1):S67-S77.
Note: This information may not
cover all possible claims, uses, actions, precautions, side effects or
interactions. It is not intended as medical advice, and should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Revised: 06/26/2007
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