Black Cohosh - How Black Cohosh Works
? - Side Effects of Use

Taxonomic Class

Ranunculaceae

Common Trade Names

Agnukliman, Black Cohosh, Cefakliman mono, Cimisan, Cirkufemal, Femilla N, Feminon C, Klimadynon, Menofem, Remifemin

Multi-ingredient preparations: Biophylin, Bronchicough, Bronchicum, Bronchicum SB (FM), CX, Dong Quai Complex, Esten (FM), Estrocare, Estroven, Female Balance, Femisana N, Femtrol, GNC Menopause Formula, Harpagophytum Complex, Helonias Compound, Herbal PMS Formula, Husten-Tee Bronchiflux (FM), 10docafedrina (FM), Lifesystem Herbal Formula 4 Womens's Formula, Ligvites, Medinat Esten, NewPhase, One-A-Day Menopause Health, Perpain (FM), PMT Complex, Proesten, Remifemin Plus, Salagesic, Super Mega B+C, Vegetable Cough Remover, Vegetex, Viburnum Complex, Women's Formula Herbal Formula 3

Common Forms

Caplets: 40 mg, 400 mg, 420 mg Capsules: 25 mg, 525 mg

Source

The crude drug is extracted primarily from the dried rhizomes and roots of Cimicifuga racemosa (Actaea racemosa). Other sources include other Cimicifuga species and Macrotys actaeoides. These plants are native to eastern North America.

Chemical Components

Several chemical compounds have been extracted from the black cohosh plant, including acteina, cimigoside, steroidal terpenes, and 27-deoxyactein . Other constituents include tannins, salicylic acid, and an isoflavone, formononetine.

Actions

Physiologic effects of black cohosh include vascular and estrogenic activity. The vascular action is attributed to acteina, which in animals produces a hypotensive effect through vagal nerve activity .

Most research has focused on the plant's estrogenic activity. In studies with rats, active constituents of the plant were found to bind directly to estrogen receptors and suppress luteinizing hormone (LH) release . A commercial extract reduced LH secretion without affecting folliclestimulating hormone in a group of menopausal women. A study of hysterectomy patients failed to show any advantage of using black cohosh over conventional hormone replacement therapy . Black cohosh improved bone mineral density in rats that were administered a low-calcium diet , but this effect has not been demonstrated in human studies.

Reported Uses

Black cohosh has been used primarily for gynecologic-related conditions, such as dysmenorrhea, menopausal symptoms, osteoporosis, and uterine spasms. It has also reportedly been used to treat arthritis, diarrhea, diuresis, dyspepsia, kidney problems, malaise, malaria, snakebite, and sore throat and as an insect repellent.

Dosage

Dosages vary and are not standardized. In studies, dosages ranged from 8 to 2,400 mg P.O. daily.

Adverse Reactions

• CV: bradycardia, hypotension.

• GI: nausea, vomiting.

• Other: increased perspiration, miscarriage or premature birth.

Interactions

• Anesthetics, antihypertensives, sedatives: May increase hypotensive effect. Avoid administration with black cohosh.

• Estrogen supplements, oral contraceptives: May increase effects. Avoid administration with black cohosh.

Contraindications And Precautions

Black cohosh is contraindicated in patients with a history of estrogen dependent tumors (such as estrogen receptor-positive breast cancer), uterine cancer, or thromboembolic disorders and in pregnant or breast­feeding patients. Hypotensive effects of acteina may be additive when taken with anesthetics, antihypertensives, o r sedatives.

Special Considerations

• Inform the patient taking an antihypertensive or a sedative of the potential additive effects of black cohosh. Monitor blood pressure closely in hypertensive patients to avoid hypotension.

• Discontinue black cohosh 2 weeks before surgery to avoid hypotensive reactions with anesthetics.

• Caution the pregnant patient that black cohosh, if taken in large doses, may cause spontaneous abortion.

• Overdose may cause CNS and visual disturbances, dizziness, headache, and tremor.

• Use of black cohosh should be limited to 6 months' duration because long-term studies on toxicity are lacking.

points of Interest

Historically, black cohosh was one of several natural ingredients in Lydia Pinkham's Vegetable Compound in the early 1900s.

Commentary

Animal and human studies on the use of black cohosh are limited. Data from these studies suggest that the herb's hormonal effects may be beneficial primarily in controlling hot flashes associated with menopause. Most clinical data regarding this plant are derived from German studies that evaluated only a small number of women. The full estrogenic activity of black cohosh has not been conclusively demonstrated in humans, and therefore, it should not be recommended as a substitute for conventional forms of hormone replacement therapy. Additional, well­controlled trials are needed to clearly define the role of black cohosh as a natural form of hormone replacement therapy.