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Black Cohosh for Hot Flashes:
Does it Work or Doesn't it?

Review of Herbalist Uses and Scientific Studies

Black cohosh for hot flashes. Is it effective? Is it safe? You don't have to search very far on the internet to find some confusing information about it.

The more I study black cohosh the more I love it. It is so much in the spotlight, and appears so controversial.

Before the baby-boomers hit menopause, it was just a well-regarded, often-used herb by those who love plants, and those who prefer an “alternative” approach to health and healing.

But now, it's in the news. Now, it's a commodity. Now, the plants are not nearly as abundant as they once were.

Black cohosh is a very useful herb for women. It can help with hot flashes, insomnia and irritability in perimenopause and menopause.

It can help lower blood pressure. It helps your brain think you have more estrogen than you do, so it provides the benefits of that without the risks.

Women have been using this herb for hundreds of years. It's native to this country, and was used by American Indians, early European Americans, and the Eclectic Doctors (American physicians who practiced between the early 1800's through the early 1900's).

According to Holmes (1998),

“After John King began publicizing it's properties in 1844, and right up to the early twentieth century, black cohosh was routinely used as an obstetrical remedy by thousands of midwives and doctors throughout the U.S.”

It was introduced into the US Pharmacopoeia in 1830 (it was later removed). It continues to be used worldwide by many cultures without incident.

But now that mainstream medicine has gotten involved, the confusion about whether or not we should use black cohosh for hot flashes and other menopausal issues is everywhere.

As is often the case when studying the effects of herbs, the latest scientific studies seem to contradict each other.

Think about it...you take 100 women of varying ages, varying hormonal levels, varying stages of health, with different diets, different life situations, different stress levels and different constitutions, and then try to make one statement about one component of an herb (that comes in varying formulas and qualities) as to whether or not it has an effect on, say, hot flashes.

How can you do that? But that is what we try to do, and it explains some of the different outcomes obtained when studying black cohosh for hot flashes.

Black Cohosh for Hot Flashes: The Plant

The botanical name is Cimicifuga racemosa or Actaea racemosa (a synonym), is a beautiful plant native to woodlands areas in eastern North America.

Other common names are Black Snakeroot and Black Bugbane, Squaw root, Macrotys. Parts used are the rhizome and roots.

Black Cohosh for Hot Flashes, Black Cohosh for Menopause

Use of this herb can reduce the amount and/or intensity of hot flashes and night sweats, relieve joint pain and headaches, and reduce water retention.

It can help with insomnia, irritability and fatigue. According to Weed (2002), it can help with vaginal lubrication and conditions of uterine or bladder prolapse. For these issues, dosage is 30 drops of the tincture once a day for one to three months. (Weed, 2002).

It has a bitter taste, so can increase digestive juices which can reduce indigestion and bloating. It moistens dry eyes (my current favorite use). It is a central nervous system depressant, and is anti inflammatory.

There are some side effects in high doses, and some people who should not take black cohosh for hot flashes or other uses. See black cohosh side effects for detailed information.

Understanding Study Reports: The HALT Study

The most recent news (February, 2012) about using black cohosh for hot flashes tends to read something like this:

“No evidence it works.”

“Uncertain efficacy.”

“Most rigorous study shows no evidence it works.”

“The evidence is mixed.”

The authors of these statements are referring to the HALT study, published in the Annals of Internal Medicine December 19, 2006. This was a year-long, randomized, double-blind, placebo-controlled trial. The trial used two different black cohosh products.

One was an extract, and the other had black cohosh along with some other herbs. The outcome did not show any evidence of reduction of hot flashes using either of the black coshosh products.

The study, however, had some limitations, which were acknowledged by the authors. One was the small size of each group of women being studied.

The study included 351 women, but they were split into five different groups. The number of women in each group “drops to a point where the statistical significance of the outcomes (whether positive or negative) are greatly diminished.” (American Botanical Council, 2006).

Another limitations was, “The trial had set a criteria for inclusion at a minimum of 2 hot flashes per day, a relatively low level at which reductions are more difficult to produce and/or monitor in a trial like this (although the actual median level was actually 6).” (American Botanical Council, 2006).

The dose studied in this group was 160mg, versus the 40mg in the studies on Remifemin, a German-produced version of the herb.

Another concern about the study was the potency of the herb used. The medical director of the company that produces Remifemin, Fredi Kronenberg, Ph.D. noted that the products used in the study did not come in blister packs, and could have been degraded during the study.

Also noted by Dr. Kronenberg was the fact that, “The media does a disservice to the public by using catchy headlines and not taking the time for the in-depth analysis so needed in reporting on what are complex issues.” (American Botanical Council, 2006).

A Meta-Analysis

Shams, Setia, Hemmings, McCusker, Sewitch, & Ciampi (2010), recently conducted a meta-analysis to review the evidence on the efficacy of black cohosh for treating menopausal symptoms.

From the abstract: “A systematic search of three databases (PuhMed. Embase, and Cochrane library) was conducted to identify relevant literature... nine randomized placebo-controlled trials were included.

Using data from seven trials, we calculated a combined estimate tor the change in menopausal vasomotor symptoms. Preparations containing black cohosh improved these symptoms overall by 26% (95% confidence interval ll%-40%); there was, however, significant heterogeneity between these trials.”

How To Use Black Cohosh for Hot Flashes and Menopausal Symptoms

The best product according to herbalists is the fresh root tincture, 10 – 30 drops, up to 4 times/day. You can make a tea and drink up to 3 cups/day, made by simmering 1 ounce of the root in a pint of water for 20 minutes.

As a bitter to stimulate digestion: 3-5 drops of tincture on your tongue (you need to taste it for it to work), a few minutes before eating.

The best way to take black cohosh is in tincture form, but the capsules below will also work if you don't like the taste.

These are the highest quality brands. The product with the most studies showing it's effectiveness is Remifemin.


American Botanical Council (2006). Black cohosh clinical trial not representative of previous research showing positive results. HerbalEGram, Volume 4. Retrieved February 26, 2012 from http://cms.herbalgram.org/heg/volume4/page47.html

Holmes, P. (1998). The Energetics of Western Herbs: Treatment Strategies Integrating Western and Oriental Herbal Medicine, Revised Third Edition, Volume 2. Boulder, CO: Snow Lotus Press.

Shams, T., Setia, M., Hemmings, R., McCusker, J., Sewitch, M., & Ciampi, A. (2010). EFFICACY OF BLACK COHOSH-CONTAINING PREPARATIONS ON MENOPAUSAL SYMPTOMS: A META-ANALYSIS. Alternative Therapies In Health & Medicine, 16(1), 36-44. Retrieved from EBSCOhost.

Weed, S. (2002). The New Menopausal Years: The Wise Woman Way. Woodstock, NY:Ash Tree Publishing.

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