Black Cohosh Adverse Effects

Black cohosh is an herb that has been used for centuries as a natural remedy for a variety of ailments in men and women but has grown to become a popular alternative treatment to counter menopause symptoms in women. Black cohosh's popularity as a cure has also brought attention to its adverse effects. Those negative reports, along with conflicting results from scientific studies, have raised a cloud of controversy over use of the herb.

Effects

• According to the American Cancer Society, possible negative effects of using black cohosh include vomiting, nausea and upset stomach. Excessive doses can cause cramps, slower heart rate, dizziness, tremors, headache, joint pain or light-headedness (Reference 4).

Warning

• There have been a small number of cases where black cohosh users have developed liver disease and for that reason, people with liver conditions are discouraged from using the herb (Reference 1). The Women's Encyclopedia of Natural Medicine states that Australia, Canada and some European countries require black cohosh products to carry a warning label about potential liver damage but in the U.S., The National Institutes of Health don't require this labeling, citing the lack of scientific evidence to show cause for concern (Reference 3).

Theories/Speculation

• Most of the scientific studies that have been performed on black cohosh have been short term; six months or less, therefore, long term effects of usage are unknown. The National Institutes of Health, however, suggest that extended use of the herb-which contains phytoestrogens-could increase risk of breast or uterine health problems (Reference 1).

Conflicting Research

• A decision is pending on whether the use of black cohosh by cancer patients interferes with traditional treatments like chemotherapy. Contradictory results have come from conducted studies; some showing the herb to retard growth of cancer cells in lab dishes but others showing black cohosh to speed growth of cancer cells in mice. Due to the confusion, cancer patients are advised to avoid use of the herb until their cancer treatment is complete (Reference 4).

Risk Groups

• Other at-risk categories are: pregnant or nursing women, who are advised to avoid black cohosh since the herb's effects on babies and fetuses is unknown. It is suggested that hypertension sufferers and women undergoing hormone replacement therapy consult their doctors prior to use. Also, individuals allergic to aspirin should avoid the herb because it contains trace amounts of salicylic acid, which chemically resembles the acetylsalicylic acid found in aspirin (Reference 4).

Considerations

• The studies that have been conducted and the adverse results that have been reported about black cohosh all stem from use of herbal dietary supplements and not from use of the natural plant, suggests Mary Tagliaferri, author of "The New Menopause Book". She indicates that black cohosh root is getting a bad rap based on medical studies that have largely based their findings on use of Remifemin the leading prepared brand which, in addition to containing pure black cohosh extract, also contains cellulose, lactose, magnesium stearate, potato starch and peppermint flavor Reference 2, 5).