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| Black Cohosh (flower) |
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| Black Cohosh (root and rhizomes) |
- originated in North America; gynecological disorder remedy by a Native Americans tribe (Algonquia). [2]
- believed cohosh = pregnancy in Algonquians. [2]
- first described in 1705 in botanist Leonard Plukenet [2]
- many early settlers adopted; long tradition of use in the United States and Europe [2]
2. Medicinal and non-medicinal use
- roots and rhizomes → tx menopausal sx (hot flashes & sleep and mood disturbance) [4]
- 19th century america home remedy → rheumatism and fever,as a diuretic that brings on menstruation [1]
- colds, cough, constipation, hives, backaches, and induce lactation [1]
- majority document reports on analgesic effects both men and women [2]
- no protective effect on developing osteoporosis [4]
3) Active ingredient(s)
There are more than 50 secondary metabolites identified, in which the main proposed bioactive constituents are N-ω-methylserotonin which is a metabolite of serotonin [2], 23-epi-26-deoxyactein and cimicifugoside which are triterpene glycosides (steroid precursors) [2] [4] [8], and fukinolic acid [1]. Ultimately, it is unclear what the active ingredients really are in black cohosh [9].
4. Theorized mechanism of Action
- fukinolic acid, compound identified, → estrogenic activity (in vitro)[1]**2,4,8
- no conclusive studies on its effect on LH, FSH, or uterus functions. (no significant)[1]
- possible agonist and competitive ligand to opioid receptors [2]
- Positron electron tomography imaging of the brains → binding in the nucleus accumbens (the placebo effect area)
- possible partial serotonin agonist and not phytoestrogen (plant-derived xenoestrogen) [7]
5) Clinical Issues The standard dose of black cohosh is two 20 mg tablets two times daily (Remifemin). It has been proposed that the 20 mg tablet two times daily may be equally effective. The standard dose for the tincture is 2 mL two times daily for a 1:1 tincture in 90% alcohol. However, the standard dosage may vary depending on the indication. The maximum effect usually occurs in four to eight weeks.
Overdose symptoms are not well known, but may include nausea, dizziness, seizures, visual disturbances, reduced pulse rate, and increased perspiration [3] Adverse reactions include allergic reactions, which are rare [3], gastric complaints [1] [12], headaches [1] [12], dizziness [12], hypotension [12], osteoporosis [12], weight problems [1], possible uterine and breast tissue effects with long-term use [1], and hepatotoxicity. While several case studies exist in regards to hepatotoxicity, there is insufficient data to determine a conclusive correlation [1] [2]. The USP however, does suggest including a cautionary statement on the label of black cohosh products: "Discontinue use and consult a healthcare practitioner if you have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice."
In regards to pregnancy use, the general consensus is to avoid use due to the potential ability to stimulate uterine contraction [3] and potential adverse outcomes to neonates [1]. However, black cohosh use in pregnancy has not been rigorously studied [1]. In regards to lactation, the degree of transmission is unknown. Breast cancer is another controversial area remains; some sources suggest black cohosh as a potential treatment and other suggest that the cancer is exacerbated [3]
Overdose symptoms are not well known, but may include nausea, dizziness, seizures, visual disturbances, reduced pulse rate, and increased perspiration [3] Adverse reactions include allergic reactions, which are rare [3], gastric complaints [1] [12], headaches [1] [12], dizziness [12], hypotension [12], osteoporosis [12], weight problems [1], possible uterine and breast tissue effects with long-term use [1], and hepatotoxicity. While several case studies exist in regards to hepatotoxicity, there is insufficient data to determine a conclusive correlation [1] [2]. The USP however, does suggest including a cautionary statement on the label of black cohosh products: "Discontinue use and consult a healthcare practitioner if you have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice."
In regards to pregnancy use, the general consensus is to avoid use due to the potential ability to stimulate uterine contraction [3] and potential adverse outcomes to neonates [1]. However, black cohosh use in pregnancy has not been rigorously studied [1]. In regards to lactation, the degree of transmission is unknown. Breast cancer is another controversial area remains; some sources suggest black cohosh as a potential treatment and other suggest that the cancer is exacerbated [3]
Drug-drug interactions are also not rigorously studied. Possible interactions include anti-estrogens, estrogens, HRT, birth control pills, BP agents, and agents that increase bleeding risk. Examples include cyclosporine, azathioprine, warfarin, and tamoxifen
6. Efficacy vs Safety
- caution with women with personal or strong family history of breast cancer [4]
- case reports of hepatotoxicity [1]
- studies down in mostly in Germany of 2,000 women show black cohosh has same efficacy as estrogen-containing product for treating menopausal symptoms[4]
- open trial, lack blinding, and long term follow-up
7) Information about the standard of the various preparations available
Extracts are standardized to 27-deoxyactein [1], in which the dosage is based on its content of triterpenes [12]. Commercially available preparations usually contain 1 mg of total 27-deoxyactein in each 20 mg dose (Remifemin) [1] [3]. Black cohosh is also available as liquids and teas [3].
8. Cost (compare to prescription medicine)
- inexpensive (<$25) [3] price from $12 to $15 (quantity or dose)
- menopausal medication [5] [6]
- oral, hormonal (estradiol replacement) many generics available, <$15 per month
- transdermal unit price > oral unit price
- non-hormonal (SSRI, MAOI, Gabapentin, alpha adrenergic agonist) most expensive
9) Prevalence of use
In the late 20th century, black cohosh gained popularity as a remedy for the hot flashes associated with menopause [2]. This was escalated by women abandoning HRT to look for safe and effective non-hormonal solutions for menopausal symptoms [10] However, the natural stands of black cohosh are threatened [2] by habitat destruction, by excessive wild harvest that is greater than the plant's natural replacement rate, and an increasing global demand. Currently, wild-harvested plant materials supply nearly all commercial sales of black cohosh, placing a strain on the natural source of the plant.
10) Evidence-based medicine
Studies have been done to determine black cohosh's effects on menopausal symptoms. Most studies assessed symptoms using the Kupperman index, a scale that combines measures of hot flashes, insomnia, and depression [1].Two randomized, double-blind, placebo-controlled trials have been performed to study the efficacy of black cohosh [1]. The results, however, are conflicting due to a lack of rigorous study design, short study duration, and difficulties in interpretation (e.g. different amounts of black cohosh from different sources used, different measurement outcomes) [1] [4]
11. Comparable prescription of non prescription medicines
- inconclusive information on its efficacy against hormonal and nonhormonal therapy for menopausal symptoms. [7]
12) View of a pharmacist
Kenneth Newman, BS Pharmacy , “I have attended a women’s health seminar recently in which they recommended using black cohosh for night sweats and other menopausal symptoms. I think its a safe place to start for some women that are having difficulty managing the symptoms but a situation has not yet arrived where someone came in to specifically look for this product. I would feel comfortable talking to someone about this, I do not know if i would be able to answer all their questions but I am certainly willing to look them up”
Nhi Pham, PharmD, “From my own look at the available literature, black cohosh would never be something I would recommend; Soy products are known to be more effective and would be the alternative that I would suggest.”
Nhi Pham, PharmD, “From my own look at the available literature, black cohosh would never be something I would recommend; Soy products are known to be more effective and would be the alternative that I would suggest.”
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