I did a little internet research on this, and found this on clinical pharmacology
"NOTE: In the US, nutraceuticals are marketed under the Dietary Supplement and Health Education Act of 1994 (DSHEA). Consequently, scientific data supporting claimed benefit(s) are not always available for nutraceuticals as they are for traditional pharmaceuticals since nutraceuticals are not regulated as drugs. Consumers should also note that rigid quality control standards are not required for nutraceuticals and substantial variability can occur in both the potency and the purity of these products. Monographs on nutraceuticals are included in CP when reliable clinical data are available. The information presented below is condensed from the best clinical data we could find.
In herbal lore, Cimicifuga racemosa is described as an 'emmenagogue', an agent used to stimulate menstrual and uterine flow, tone, and activity. Cimicifuga racemosa is commonly known as black cohosh, and is sometimes referred to as black snakeroot, squaw root, or bugbane. It has several historical uses in women's health. Native Americans used black cohosh dried rhizome and roots to aid childbirth, and treat female complaints and snakebites; black cohosh was an official drug in the US Pharmacopoeia from 1830—1926. Currently, the FDA does not recognize black cohosh as 'GRAS' (generally safe and effective). In the US, sales of black cohosh exceed 6.3 million dollars annually.
Black cohosh was one of the ingredients in the patent combination herb product known as Lydia E. Pinkham's Vegetable Compound of the late 1800's and early 1900's; the compound may be still be found in some drugstores in the US. Lydia Pinkham claimed the compound could treat a multitude of female health problems, including infertility. A popular advertisement of the day proclaimed 'there is a baby in every bottle'. No scientific evidence exists from which one can evaluate this claim. A similar combination herb formulation is also now marketed in the US under the name of Olivia's Secret™ for the relief of symptoms related to premenstrual syndrome and menopause. Other preparations include Estroven™, a combination product containing black cohosh, soy isoflavones, kava kava, vitamins, and minerals. Remifemin™ contains only black cohosh, and has been one of Germany's top proprietary herbs since the 1960's. Germany's Commission E has found this extract of black cohosh effective for the treatment of dysmenorrhea, PMS, and climacteric neurovegetative ailments since 1989. No other uses or formulations have the Commission's approval.
Black cohosh is commonly found in many proprietary herbal or homeopathic remedies used in the practice of midwifery (e.g., Pregnancy-6™, PN-6, and Combination 5W™). Black cohosh (Cimicifuga racemosa) is typically combined with blue cohosh (Caulophylum thalictroides), a very different herb, to stimulate term labor. Recent surveys indicate that roughly 45% of midwives use black cohosh for this purpose. In February 2000, the FDA released a warning letter to dietary supplement manufacturers that advised against making any claims related to pregnancy. The letter was released following concerns of the potential for birth defects from the use of untested products."
"Black cohosh should be considered to be classified in pregnancy category X for use during the first, second, and the majority of the third trimester of pregnancy. The potential effects on the endocrine cycle, particularly on luteinizing hormone (LH), could potentially harm the fetus. In addition, the effects of black cohosh on uterine contractions could be detrimental to the maintenance of the pregnancy (i.e., may contribute to spontaneous abortion risk). Black cohosh has received widespread use historically as a part of combined herbal regimens used to augment labor and obstetric delivery in normal term pregnancies; however, no controlled clinical trials have evaluated black cohosh's use for this purpose. In February 2000, the FDA released a warning letter to dietary supplement manufacturers that advised against making any claims related to pregnancy on their products. The letter was released following concerns of the potential for birth defects from the use of untested products. Complications in neonates have been reported (see Adverse Reactions). Maternal complications have also been noted in select cases. When used in the last 5 weeks of gestation, black cohosh may induce precipitous labor. Black cohosh would be contraindicated for use during any complication of pregnancy such as: abnormal fetal position, preeclampsia and eclampsia, fetal distress, fetal prematurity, incomplete abortion, intrauterine fetal death, multiparity, placenta previa, and premature rupture of membranes (PROM)."
HTH! Good luck in your journey. I'm curious to see if anyone else has taken this... what did you think?