Physiological Investigation of a Unique Extract of Black Cohosh (Cimicifugae racemosae rhizoma): A 6-Month Clinical Study Demonstrates No Systemic Estrogenic Effect

Abstract

The higher dose did not exert a significantly greater effect on any end point. Thus, the currently recognized standard dose of the isopropanolic aqueous C. racemosa extract should be preferred over the higher dose. Despite the absence of a placebo group, this study suggests that C. racemosa extract is associated with improvement in menopause symptoms without evidence of estrogenlike effects.

Critical evaluation of the safety of Cimicifuga racemosa in menopause symptom relief

“…18,23 Although early reports indicate the effectiveness of Cimicifuga for a variety of indications, Cimicifuga extracts are used today primarily for the treatment of menopausal symptoms. Clinical evaluations [24][25][26][27][28][29][30][31] support early reports suggestive of Cimicifuga use for relief of menopausal complaints. 32 Since its introduction as a medicinal agent, clinical effects of Cimicifuga have been noted in various preparations, including rhizome powders, tinctures, infusions, and fluid or solid extracts.…”

“…To confirm the safety of the commercially accepted doses of isopropanolic Cimicifuga extract, Liske and colleagues 31 conducted a 24-week controlled, randomized, double-blinded parallel-group study of two doses of the isopropanolic Cimicifuga preparation [Remifemin (standard dose: 39.0 mg/day; high dose: 127.3 mg/day)] in 152 perimenopausal and postmenopausal women. Both the standard-and high-dose groups reported "good" and "very good" tolerability ratings (standard: 94.7% at 12 weeks and 100% at 24 weeks; high: 82% at 12 weeks and 100% at 24 weeks), and adverse-event reports for both dose groups were comparable.…”

“…87 Therefore, estrogenic activity would likely result in decreased levels of LH and FSH. A clinical trial of perimenopausal and postmenopausal women that investigated the effects of Cimicifuga on the female reproductive system over a 24-week period evaluated the physiologic effects of the medicinal herb based on vaginal cytology measures (degree of cell proliferation in the vaginal epithelium, the karyopyknotic index, and the eosinophilic index) and reproductive hormone lev- 31 The vaginal cytology measures demonstrated that Cimicifuga did not induce cell proliferation or other adverse effects nor cause significant alterations in E 2 , LH, FSH, prolactin, and sex hormone-binding globulin levels after treatment with the standard (39.0 mg/day) or high (127.3 mg/day) dose of Cimicifuga. On the basis of vaginal cytology and hormone findings from this clinical study, it appears that the beneficial effects of Cimicifuga extracts on menopausal symptoms are not associated with systemic estrogenagonistic effects.…”

“…On the basis of clinical experiences with commercial products, the currently recommended dose of Cimicifuga is a 40% to 60% ethanol or isopropanol extract in a daily dose of 40 to 80 mg herbal drug that is quality controlled for quantity of triterpene glycosides. 35 A recently published study 31 demonstrated that there is no superiority of a high dose of Cimicifuga (127 mg/day) over the currently recognized 40 mg/day dose, thus supporting the current recommended extract dose. Despite these findings, many have advocated the use of a higher daily dose (80 mg) on the basis of the safety profile of Cimicifuga.…”

The Cimicifuga preparation BNO 1055 vs. conjugated estrogens in a double-blind placebo-controlled study: effects on menopause symptoms and bone markers

“…Thus, the compliance of patients for HRT decreases. Experiments in rodents as well as clinical studies in postmenopausal women demonstrated that CR extracts do not have uterotrophic effects [14,15], which was the basis for the assumption that they do not contain estrogenic compounds [16]. Yet, in ovariectomized rats, the aqueous/ethanolic extract BNO 1055 exerted estrogenic effects in the hypothalamus, in the bone and in the vagina (Wuttke et al, and Seidlová-Wuttke et al, this volume).…”