| clinical studies of cimicifuga racemosa have almost all utilized remifemin®, a standardized extract containing triterpene glycosides, 1 mg/ablet, calculated as 27-deoxyactein. the usual dose had been 2 tablets twice daily (equivalent to 4 mg triterpene glycosides per day). dosages twice this amount have been used in some studies. recent information from the makers of remifemin¨ has documented that half of this standard dose, i.e., 1 tablet 2x/ay or a total of 2 mg triterpene glycosides, is as effective as 2 tablets 2x/ay for the relief of climacteric symptoms. [note: 40 drops of the standardized remifemin¨ liquid extract is equivalent to 40 mg of herbal drug, or 2 tablets containing a total of 2 mg triterpene glycosides. the study to support the revised dosage claim is currently in press (schaper & brümmer 1997).)
Because the revised recommended dose for Black Cohosh, equivalent to 40 mg of herbal drug/day of an extract (i.e., Remifemin®) standardized to contain 2.5 % triterpene glycosides (or 2 mg of triterpene glycosides/day) is supported by clinical data, we recommend that this dosage guideline should be followed in most instances. For liquid extracts, the total daily dose should be 40 drops of standardized extract containing 5% triterpene glycosides, and for solid extracts, the dose should be equivalent to 40 mg extract containing 5% tritrepene glycosides. The actual weight and number of tablets or drops administered may vary depending on how the product is standardized. Additional dosage information (see below) is available from other sources and is included here in the interest of thoroughness.
The British Herbal Compendium (1992) recommends a dose of 40 - 200 mg dried rhizome, or 0.4 - 2 ml of a 1:10 60% ethanol tincture (Bradley 1992). However, Newall et al. (1996) report a dose range of 2-4 ml of this tincture (BPC 1934). They further describe a dose range of a liquid extract (BP 1898) of 1:1 in 90% alcohol as 0.3-2.0 ml. Rhizome decoction dose is given as 0.3-2.0 g, 3X/day.
Overdoses may produce nausea, vomiting, and dizziness and may reduce pulse rate and induce perspiration. Overdosing during pregnancy can cause premature birth (Duke 1985). Although not listed as toxic, it is classified by the FDA as an herb of undefined safety.
Overdosing of Cimicifuga species used in Shengma (CTM) causes lassitude, vertigo, tremor, severe headache, slow pulse, and collapse (Chang & But 1986).
Toxicity assessments for the chloroform extract (Minimum lethal dose, MLD) range from as low as >3.0 mg/kg (s.c, 30 days) in the rabbit to as high as >1 g/kg (oral, 30 days) in the rat (NAPRALERT, 1997). In Wistar rats given up to 5000 mg Remifemin® granulate/kg for 26 weeks, no conspicuous chemical or organ toxicities were observed (Korn, 1991). In human studies with the fluid extract, up to 890 mg/day was given with no evidence of toxic effects (Novitch & Schweiker, 1982)
Ames test (in vitro Salmonella microsomal assay) results showed no evidence of mutagenic potential of the isopropanolic extract of C. racemosa (Liske 1998). Dosages of 0.32 to 1000 micrograms per plate were used with negative and positive controls. (Schaper & Brümmer 1997).
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