Black cohosh is a plant that is native to eastern North America and has a long history of use in traditional medicine.
Native Americans used this plant as a medicine more than two hundred years ago for gynecological issues, sore throat, and depression.
Today, the rhizomes and roots of this flowering perennial are used mainly for menstrual cramping and symptoms associated with menopause. In Germany, it is an approved medicine for treating PMS (premenstrual syndrome) and dysmenorrhea (painful menstruation).
Research shows it can benefit mood swings, hot flashes, irritability, and sleep disturbances associated with menopause. [2]
This herb is also being studied for cardiovascular disease, cancer, infertility, osteoarthritis, and more. [1, 2, 3]
This article will discuss what black cohosh is, how it works, health benefits, how this supplement should be used, side effects and possible drug interactions.



- Source of natural phytoestrogens
- May modulate estrogen receptors
- Supports hormone balance & bone health
Black Cohosh Plant Description
Black cohosh (Actaea racemosa, synonym Cimicifuga racemosa) is an angiosperm from the Ranunculaceae botanical family. [2]
It is also commonly called black snakeroot, black bugbane, and fairy candle. [2]
This herb grows up to 8 feet tall and produces a long plume of small white flowers. It grows from the southern border of Ontario, Canada into central Georgia, USA, and from the east coast westward to Arkansas. [2]
Black cohosh is often found growing in small openings in a variety of woodland habitats. The word “black” in the name describes the plant’s dark-colored rootstalk.
“Cohosh” is an Algonquin word meaning “rough,” which refers to the woody texture of the plant’s roots and rhizomes. [2]
How Does Black Cohosh Work in the Body?
The University of Maryland Medical Center (UMM) states that black cohosh contains several bioactive chemicals.
These include sugar-based compounds called glycosides, plant-based estrogen-like compounds (phytoestrogens), and an anti-inflammatory compound called isoferulic acid. [1]
According to the Natural Medicines Comprehensive Database (NMCD), the active constituents include:
- Phytosterin
- Isoferulic Acid
- Fukinolic Acid
- Caffeic Acid
- Salicylic Acid
- Sugars
- Tannins
- Long-Chain Fatty Acids
- Triterpene Glycosides (Acetein, Cimicifugoside, 27-Deoxyactein [5]
The National Center for Complementary and Integrative Health (NCCIH) is currently funding research to identify other bioactive compounds in this plant. Researchers are also examining their effects in the body. [2]
One of the purported mechanisms of action for black cohosh extract is anti-inflammatory activity.
When inflammation occurs, macrophages and neutrophils (two types of white blood cells) secrete a serine proteinase called neutrophil elastase. This enzyme can destroy harmful bacteria, but it can also destroy healthy tissues in its host organism.
Black cohosh contains the compound fukinolic acid. This phytochemical is known to inhibit the inflammatory activities of neutrophil elastase. [5]
Black cohosh has been observed to cause estrogenic effects by a currently unknown mechanism. In laboratory research, it does not bind with estrogen receptors, promote growth of estrogen-dependent tumors, or increase estrogen-dependent genes. [5]
In clinical studies, black cohosh has not been seen to alter levels of sex hormones including luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (estrogen), or prolactin.
There is some evidence from animal studies suggesting it may inhibit secretion of LH from the pituitary gland. [5]
Some preliminary evidence suggests that black cohosh could act as a partial agonist at various serotonin receptors. Serotonin is a chemical messenger in the brain and central nervous system (neurotransmitter).
This means that it may interact with these receptors and activate them in the same way as the body’s natural serotonin neurotransmitter. It is hypothesized that this effect may play a role in reducing menopausal symptoms. [5]
Some preliminary evidence suggests that black cohosh may increase osteoblast activity. [5] An osteoblast is a cell that secretes the matrix necessary for bone formation.
There is conflicting evidence on the effects of black cohosh on cancer. There is a concern that because it has estrogenic effects that it may promote the growth of certain cancers.
Some in vitro evidence research has found that certain constituents of black cohosh (actaealactone and cimicifugic acid G) slightly increase breast cancer cell growth. [5]
However, according to the NMCD, “In vitro research suggests that black cohosh or its constituents can inhibit the growth of breast cancer cells or other estrogen-responsive cancer cell lines.” [5]
Results from animal research suggests that it neither increases nor decreases the risk of developing breast cancer. [5] But some studies have found that it can increase metastasis (tumor growth) in animals with existing cancer. [5]
The NMCD states that women who have existing breast cancer, or those with a high risk for developing breast cancer, should not use black cohosh suplements. [5]
In in vitro studies, black cohosh seems to slow down the proliferation (rapid replication and spread) of prostate cancer cells. The mechanism of action for inhibiting tumor growth is not known. It does not seem to alter testosterone levels. [5]
In vitro research suggests that this herb may increase the toxicity of commonly-prescribed chemotherapy agents such as Taxotere (docetaxel) and Adriamycin (doxorubicin). [5]
In animal models, black cohosh seemed to decrease cytotoxicity commonly associated with another chemotherapy drug called Platinol (cisplatin). [5]
In in vitro studies, it appears to work against HIV (human immunodeficiency virus) by slowing down the replication of the virus inside immune system cells called lymphocytes. [5]
Preliminary in vitro studies suggest that triterpene compounds in this plant may slow down the activities of cytochrome P450 3A4 enzymes by as much as 44%. However, this effect has not been duplicated in humans. [5]
Black Cohosh Uses and Health Benefits
The NMCD reports that people take black cohosh capsules orally for a number of different uses, including:
- Anxiety
- As a mild sedative
- Breast cancer
- Cardiovascular disease
- Cognitive function
- Coughs
- Dysmenorrhea
- Fever
- Indigestion
- Infertility
- Inducing labor
- Menopause symptoms
- Osteoporosis
- Osteoarthritis
- Premenstrual syndrome (PMS)
- Rheumatoid arthritis
- Sore throat [5]
It is also used topically as a cream for acne, as an insect repellent, mole and wart removal, rattlesnake bites, and improving skin appearance. [5]
The NMCD rates black cohosh extracts as Possibly Effective for reducing menopausal symptoms such as hot flashes. [5]
This supplement is being studied for use in a number of other conditions as well. Promising results have been seen in clinical research on breast cancer, infertility, osteoarthritis, osteoporosis, and rheumatoid arthritis. [5]
This research is limited though, and more clinical studies are needed to determine the therapeutic efficacy of black cohosh for these and other conditions.
Black cohosh is regulated a dietary supplement and the FDA has not approved it as a drug to prevent or treat any medical conditions.
Black Cohosh for Menopausal Symptoms
1]
According to UMM, some studies have found that black cohosh improves menopause symptoms, but other studies have not shown positive results. [Variability in preparations of products used in clinical trials may affect results. [5]
Consistent results have been seen in clinical trials that use the standardized commercial product Remifemin produced by Phytopharmica/Enzymatic Therapy.
This extract contains 1 mg of triterpene glycosides (measured as 27-deoxyactein content) in each 20 mg tablet. [5]
In multiple clinical trials, this specific product has been observed to reduce menopause symptoms such as hot flashes, sweating, anxiety, and insomnia. [5]
Some studies have compared black cohosh to conventional treatment plans such as hormone replacement therapy (HRT) and fluoxetine (Prozac).
One study compared this supplement to low-dose transdermal (absorbed through the skin) estrogen. It was found that both treatments similarly reduced hot flashes per day, depression, and anxiety. [5]
In one study involving 120 menopausal women, black cohosh significantly decreased hot flashes and night sweats and was more effective than the common antidepressant medication Prozac.
However, greater improvements were seen on depression scale ratings in the Prozac group. [1]
According to UMM, some experts think black cohosh may be a safe and effective alternative for women who are unable to use hormone replacement therapies for combating menopause symptoms. [1]
However, other experts believe that there is insufficient evidence to support the use of this herbal extract for menopause symptoms.
Guidelines from the American College of Obstetricians and Gynecologists state that the available data does not show this supplement to be effective for treating hot flashes and night sweats. [6]
Some doctors recommend limiting the use of black cohosh for relieving hot flashes to 6 months. They believe early safety studies may have been flawed and are waiting for new data before recommending longer usage periods. [1]
Research trials are on-going to better understand the potential therapeutic efficacy of black cohosh for menopause symptoms and hormone balance.
If you are going through menopause and are interested in black cohosh as an alternative to traditional treatment then it is recommended that you speak with your doctor for more information.
Black Cohosh and Breast Cancer
Research results on the use of black cohosh for breast cancer prevention are conflicting.
According to NMCD, one population study found that taking black cohosh supplements routinely may decrease the long-term risk of breast cancer.
In another population study in women diagnosed with breast cancer, black cohosh extract was associated with an increased period of disease-free survival. [5]
However, other epidemiological studies failed to find an association.
One long-term study measured the risk of breast cancer development in postmenopausal women who took a variety of supplements including black cohosh, fish, oil, St. John’s wort, soy, and dong quai.
It was found that fish oil use may be associated with a decreased risk of breast cancer. However, no decrease in risk was seen with the other supplements. [5]
The UMM states that certain herbal supplements, including black cohosh, might alter the effects and/or side effects of common breast cancer treatment options, like chemotherapy and radiation. [1]
In a case-control study with 1524 controls and 949 cases of breast cancer, using black cohosh was found to induce significant protective effects against developing breast cancer. [1]
It is recommended that you speak with your doctor or oncologist before beginning to use any herbal supplements if you have cancer.
According to the UMM, “Patients with a history of breast cancer, risk factors for breast cancer, or who are actively engaged in breast cancer treatment, should talk to their doctor before taking black cohosh.” [1]
Cardiovascular Disease
According to the NMCD, preliminary evidence shows that 40 mg/day of a black cohosh extract called CR BNO 1055 does not significantly decrease the risk of cardiovascular disease in postmenopausal women. [5]
One study found a slightly increased risk of coronary heart disease when black cohosh supplementation was combined with exercise. This effect was also seen in the control group, but not in the exercise alone group or the black cohosh alone group. [3]
Research in this area is very limited. More research is needed to tell if and how black cohosh may affect cardiovascular disease risk factors.
Cognitive Function
The NMCD reports on one preliminary study that used 128 mg/day doses of black cohosh extract for 12 months. In this study, the extract used was standardized to contain 7.27 mg of triterpene glycosides per dose.
Researchers concluded that the extract did not significantly improve memory or attention performance relative to a placebo agent. [5] Research is ongoing in this area.
Infertility and Labor Induction
In one preliminary clinical trial, taking black cohosh along with clomiphene citrate increased pregnancy rates in infertile women by 23% compared to taking clomiphene citrate alone. [5]
This supplement is sometimes used to induce labor in pregnant women. The NMCD states that black cohosh may have uterine stimulant effects. It is estimated that as many as 45% of midwives use this herb to induce labor in pregnant women at term. [5]
Observational reports suggest that taking this supplement to induce labor does not negatively affect the mother or baby. However, no clinical trials have been conducted to determine the safety of this use. [5]
At this time both the UMM and the NMCD recommended women avoid using black cohosh extracts for any purpose during pregnancy because of the lack of reliable safety data. [5]
Osteoarthritis
Preliminary evidence suggests that twice daily doses for 2 months of a supplement called Reumalex may improve osteoarthritis pain. However, it did not seem to improve joint function. [5]
Osteoporosis
Evidence on black cohosh effects for osteoporosis is conflicting.
In one preliminary trial, postmenopausal women using CR BNO 1055 for 12 weeks had increased bALP (bone-specific alkaline phosphatase) levels. This is a positive marker for bone development. [5]
In another clinical trial, bone mineral density was found to be the same in the CR BNO 1055 treatment group compared to two control groups.
More research is needed to understand how black cohosh extract might affect bone structure and formation, or reduce the risk for bone fractures in patients with osteoporosis. [5]
Black Cohosh Supplements and Dosage
The UMM states that black cohosh supplements are available in tablet, capsule, tincture, liquid extract, and whole root/rhizome forms. [1]
The NMCD reports that the following dosages have been used in clinical research:
- Menopause symptoms: 20-40 mg Remifemin per day, containing 1 mg 27-deoxyactein
- Migraine headaches: 25 mg per day, containing 8% triterpenes
- Osteoarthritis: 35 mg per day
- Osteoporosis: 40 mg per day
- Rheumatoid arthritis: 35 mg per day [5]
For adults, recommended dosages range between 20 and 80 mg/day. UMM states that these tablets should be standardized to contain 1 mg of 27-deoxyactein. [1]
Most black cohosh supplements on the market provide between 40-540 mg per serving size. The large range in dosages is due to differences in standardization and the form of the supplement (whole herb versus extract).
Most supplements are standardized to triterpene glycoside content, specifically 27-deoxyactein content. [5]
Some supplements provide 400 mg black cohosh containing 1 mg of triterpene glycosides. Other supplements contain 40 mg herbal extract with 1 mg of triterpene glycosides and are made at a different standardization level.
Regardless of the dosage amount, look for supplements that have been standardized to contain between 1-2 mg of triterpene glycosides (as 27-deoxyactein) per dose. Read the label of any product you are interested in to determine the amounts of these active compounds.
Those using a liquid black cohosh tincture should consume amounts that equal between 2 and 4 mL, included 1 to 3 times daily in water, tea, or other liquids. [1]
When using whole dried root or rhizome, the plant material is normally steeped in hot water to make a tea. It has been suggested to steep 20 grams of whole dried root or rhizome in 34 ounces of purified water.
Steep the roots or rhizome in hot, but not boiling, water for at least 15 minutes. Strain discard plant pieces and then drink hot or store in refrigerator for up to 48 hours. Drink up to 3 cups daily. [1]
Users report that black cohosh extracts can take up to 2 weeks to begin causing effects. According to the NCCIH it can take up to 8 weeks for full effects to be experienced. [2]
Black Cohosh Side Effects
The Natural Medicines Comprehensive Database rates black cohosh as Possibly Safe when used orally and appropriately. Use during pregnancy and lactation is rated as Possibly Unsafe and should be avoided. [5]
The UMM states that black cohosh is not currently recommended for pediatric use. Children should not be given this herb unless their doctors prescribe it. [1]
The NCCIH states that this plant extract has been used in clinical trials for as long as 12 months without causing any serious side effects. [2]
Black cohosh is generally well tolerated in most users. Minor side effects have been reported and commonly include gastrointestinal upset and skin rash. [5]
The UMM states that some users have also reported abdominal pain, labored breathing, headaches, joint pains, weight gain, tremors, and vomiting. [1]
According to Drugs.com, black cohosh overdose can cause perspiration, slow pulse, disturbed vision, dizziness, nausea, and/or alterations of nervous system activities. [4]
There is some concern that this supplement may cause liver disease or toxicity due to several case reports in women who took products either alone or with other ingredients. [5]
However, it is unknown if the black cohosh caused these effects or if the adverse reactions were linked to other ingredients in these supplements. Research is needed to determine the potential hepatic effects of black cohosh. [5]
Drug Interactions and Contraindications
The UMM states that black cohosh should not be used in those with hormone-sensitive cancers, such as breast, prostate, endometrial, uterine, and testicular cancer.
Be careful using black cohosh supplements if you have liver disease/dysfunction, or if you use medications that are hepatotoxic. This herb might alter the effects and/or side effects of drugs that are metabolized inside the liver. [1]
This supplement may interact with some medications including atorvastatin (Lipitor), Cisplatin (Platinol-AQ), and Cytochrome P450 2D6 substrates such as imipramine (Tofranil), paroxetine (Paxil), and risperidone (Risperdal).
It is recommended that you speak with your doctor before you begin using a black cohosh supplement. This is especially important if you are currently taking any prescription drugs, herbs, or supplements, or have any health conditions.
- University of Maryland Medical Center. Black Cohosh. Accessed Feb.14, 2017
- NCCIH. Black Cohosh. NCCIH Publication No.: D268 Updated: September 2016
- Examine. Black Cohosh. Accessed Feb. 14, 2017
- Drugs.com. Black Cohosh. Accessed Feb. 14, 2017
- Natural Medicines Comprehensive Database. Black Cohosh Monograph. Accessed Feb. 13, 2017
- National Institutes of Health Office of Dietary Supplements. Black Cohosh Fact Sheet for Health Professionals.
Article last updated on: June 23rd, 2018 by Nootriment