Black Cohosh

Black cohosh is said to be useful for menopausal symptoms (eg, hot flushes, mood lability, tachycardia, vaginal dryness), for menstrual symptoms, and for arthralgias in rheumatoid arthritis or osteoarthritis.

Evidence regarding benefit of black cohosh in relieving menopausal symptoms is conflicting. There are few reliable data on its effectiveness for other disorders and symptoms.Evidence regarding benefit of black cohosh in relieving menopausal symptoms is conflicting. There are few reliable data on its effectiveness for other disorders and symptoms.

Data from several randomized trials do not support the efficacy of black cohosh for reducing menopausal symptoms. For example, a systematic review including 16 randomized trials with 2027 perimenopausal or postmenopausal women found no significant difference in the frequency of hot flushes (3 trials; 393 women) or in menopausal symptom scores (4 trials; 357 women) when comparing oral preparations of black cohosh (average dose 40 mg) with placebo (Data from several randomized trials do not support the efficacy of black cohosh for reducing menopausal symptoms. For example, a systematic review including 16 randomized trials with 2027 perimenopausal or postmenopausal women found no significant difference in the frequency of hot flushes (3 trials; 393 women) or in menopausal symptom scores (4 trials; 357 women) when comparing oral preparations of black cohosh (average dose 40 mg) with placebo (1). Another meta-analysis of randomized trials of botanical products that included black cohosh also found no benefit for menopausal symptoms (). Another meta-analysis of randomized trials of botanical products that included black cohosh also found no benefit for menopausal symptoms (2).

By contrast, findings from randomized trials suggest there may be a favorable effect of black cohosh for reducing vasomotor symptoms. For example, a network meta-analysis in women with an intact uterus found that, compared to placebo, By contrast, findings from randomized trials suggest there may be a favorable effect of black cohosh for reducing vasomotor symptoms. For example, a network meta-analysis in women with an intact uterus found that, compared to placebo,black cohosh decreased vasomotor menopausal symptoms. However, black cohosh was not as effective as hormonal treatments (3). In addition, another large systematic review found benefit of isopropanolic black cohosh extract compared to placebo for psychological and neurovegetative symptoms (eg, sleep, concentration, fatigue) of menopause (4). The product appeared to be more effective in higher doses or when combined with St. John's wort. Nonetheless, these findings are limited based on the lack of standardization of the supplement product used between studies. A subsequent large meta-analysis of 22 randomized trials including 2310 menopausal women comparing black cohosh monotherapy or combined with other herbal extracts reported that compared to placebo, menopausal symptoms, hot flushes, and somatic symptoms significantly improve, but depressive and anxiety symptoms do not (). The product appeared to be more effective in higher doses or when combined with St. John's wort. Nonetheless, these findings are limited based on the lack of standardization of the supplement product used between studies. A subsequent large meta-analysis of 22 randomized trials including 2310 menopausal women comparing black cohosh monotherapy or combined with other herbal extracts reported that compared to placebo, menopausal symptoms, hot flushes, and somatic symptoms significantly improve, but depressive and anxiety symptoms do not (5).

Adverse effects are uncommon. The most likely are headache, rash, and gastrointestinal distress. Dizziness, diaphoresis, and hypotension (if high doses are taken) may occur.

Black cohosh is contraindicated in patients with aspirin sensitivity, liver disease, hormone-sensitive cancers (eg, certain kinds of breast cancer per animal data), stroke, or high blood pressure. The U.S. Pharmacopeia (USP), based on a few case reports (is contraindicated in patients with aspirin sensitivity, liver disease, hormone-sensitive cancers (eg, certain kinds of breast cancer per animal data), stroke, or high blood pressure. The U.S. Pharmacopeia (USP), based on a few case reports (6), has recommended that black cohosh products be labeled with a warning declaring that they may be hepatotoxic.), has recommended that black cohosh products be labeled with a warning declaring that they may be hepatotoxic.

Additionally, a woman developed bradycardia due to reversible complete heart block after taking an herbal supplement containing black cohosh (7).

There is little clinical evidence that black cohosh interferes with medications. However, an in vitro study suggested that black cohosh may inhibit the biotransformation or effectiveness of tamoxifen and irinotecan, both chemotherapy agents (may inhibit the biotransformation or effectiveness of tamoxifen and irinotecan, both chemotherapy agents (8). Hepatotoxicity may occur when used concomitantly with medications that can adversely affect hepatic function (9).

1. 1. Leach MJ, Moore V. Black cohosh (Cimicifuga spp.) for menopausal symptoms. . Black cohosh (Cimicifuga spp.) for menopausal symptoms.Cochrane Database Syst Rev. 9:CD007244, 2012. doi: 10.1002/14651858.CD007244.pub2

2. 2. Franco OH, Chowdhury R, et al. Use of plant-based therapies and menopausal symptoms: a systematic review and meta-analysis. JAMA. 315(23):2554-63, 2016. doi: 10.1001/jama.2016.8012

3. 3. Sarri G, Pedder H, Dias S, et al. Vasomotor symptoms resulting from natural menopause: a systematic review and network meta-analysis of treatment effects from the National Institute for Health and Care Excellence guideline on menopause. BJOG. 124(10):1514-1523, 2017. doi: 10.1111/1471-0528.14619

4. 4. Castelo-Branco C, Gambacciani M, Cano A, et al. Review & meta-analysis: isopropanolic black cohosh extract iCR for menopausal symptoms - an update on the evidence. . Review & meta-analysis: isopropanolic black cohosh extract iCR for menopausal symptoms - an update on the evidence.Climacteric. 24(2):109-119, 2021. doi:10.1080/13697137.2020.1820477

5. 5. Sadahiro R, Matsuoka LN, Zeng BS, et al. Black cohosh extracts in women with menopausal symptoms: an updated pairwise meta-analysis. . Black cohosh extracts in women with menopausal symptoms: an updated pairwise meta-analysis.Menopause. 2023;30(7):766-773. doi:10.1097/GME.0000000000002196

6. 6. Lim TY, Considine A, Quaglia A, et al. Subacute liver failure secondary to black cohosh leading to liver transplantation. . Subacute liver failure secondary to black cohosh leading to liver transplantation.BMJ Case Rep. Published online: 5 July 2013. doi:10.1136/bcr-2013-009325

7. 7. McKenzie SC, Rahman A. Bradycardia in a patient taking black cohosh. . Bradycardia in a patient taking black cohosh.Med J Aust.193(8):479-481, 2010. doi:10.5694/j.1326-5377.2010.tb04006.x

8. 8. Gorman GS, Coward L, Darby A, et al: Effects of herbal supplements on the bioactivation of chemotherapeutic agents. J Pharm Pharmacol. 65(7):1014-1025, 2013. doi: 10.1111/jphp.12055

9. 9. Enbom ET, Le MD, Oesterich L, Rutgers J, French SW. Mechanism of hepatotoxicity due to black cohosh (Cimicifuga racemosa): histological, immunohistochemical and electron microscopy analysis of two liver biopsies with clinical correlation. . Mechanism of hepatotoxicity due to black cohosh (Cimicifuga racemosa): histological, immunohistochemical and electron microscopy analysis of two liver biopsies with clinical correlation.Exp Mol Pathol 2014;96(3):279-283. doi:10.1016/j.yexmp.2014.03.003

The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.

1. National Institutes of Health (NIH): Black cohosh