Blue cohosh

Blue cohosh is from the Berberidaceae, or barberry, family. The plant has dark blue berries and small, white flowers. Blue cohosh is generally classed as a uterine tonic which has both stimulating and relaxing properties which facilitate childbirth, similar to raspberry (Rubus idaeus) and black cohosh (Actaea racemosa) which is not related despite the similar name. Blue cohosh produces contractions which are regular and effective, interspersed with a good relaxation period. It is said to be most helpful when delay in childbirth is due to weakness, fatigue or ‘lack of uterine power’. It was a favourite remedy amongst Native American women for false pains and after pains. Historically it was used to prepare the uterus for labour (partus praeparator), for period pain and for various ‘inflammations’ of the uterus. It also acts as a relaxant and tonic to the nervous system. Traditionally, blue cohosh has been used as a diaphoretic, diuretic, expectorant and for arthritis, but it is used most commonly in pregnancy and gynaecology, most specifically as a way to avoid conventional methods of induction. 

Case reports of adverse events in recent years, however, have called for an evaluation of the plant’s pharmacological and safety data. Reports of toxicity associated with blue cohosh, combined with its continued popularity as a natural birthing aid, prompted The American Herbal Pharmacopoeia (AHP) to publish a monograph. “Blue cohosh has been implicated in a few cases of toxicity that include neonatal cardiac toxicity and maternal toxicity,” said AHP Executive Director Roy Upton. “Because blue cohosh was the primary herb used in birthing practices of herbalists, integrated medical doctors, and midwives for more than 100 years, we felt it was important to address this concern.” The AHP monograph notes that Eclectic physicians in the latter part of the 19th and early part of the 20th centuries almost always used the herb in combination formulas, “which inherently limits the exposure to potentially toxic substances.” Upton says, ”it may still prove to be a safe and effective induction agent when used by highly trained and experienced birthing professionals, but concern regarding potential toxicity has limited its use in birthing.” A review of the data suggests that blue cohosh is indeed associated with certain adverse events reported, but confounding factors make it impossible to establish a causal relationship. The monograph stressed the “need to use the herb within the context of those most experienced with it and in the context of how it was most widely used traditionally, in combination with other botanicals.” 

A combination of blue and black cohosh has been shown to be effective in ripening the uterus for augmenting labour. There were claims of neurological toxicity in a newborn after using this combination however they were formally disputed on the grounds that the toxic effects suggested would only occur if much higher doses than reported were consumed. Caution is therefore advised with this herb during pregnancy. 

References

McIntyre A. The Complete Woman’s Herbal. Gai Books Limited:London. 1994. p. 26

Blue Cohosh Root & Rhizome monograph. American Herbal Pharmacopoeia. 2012.

Smith T. American Herbal Pharmacopoeia Publishes Blue Cohosh Monograph. HerbalGram Winter 2012;96:18. https://www.herbalgram.org/resources/herbalgram/issues/96/table-of-contents/hg96-orgnews-blkcohosh/

Trickey R. Women, Hormones and the Menstrual Cycle. 3rd edn. Fairfield: Melbourne Holistic Health Group. 2011. p. 293