Black cohosh (Cimicifuga spp.) for menopausal symptoms

  • Review
  • Intervention




Menopause can be a distressing and disruptive time for many women, with many experiencing hot flushes, night sweats, vaginal atrophy and dryness. Postmenopausal women are also at increased risk of osteoporosis. Interventions that decrease the severity and frequency of these menopausal symptoms are likely to improve a woman's well-being and quality of life. Hormone therapy has been shown to be effective in controlling the symptoms of menopause; however, many potentially serious adverse effects have been associated with this treatment. Evidence from experimental studies suggests that black cohosh may be a biologically plausible alternative treatment for menopause; even so, findings from studies investigating the clinical effectiveness of black cohosh have, to date, been inconsistent.


To evaluate the clinical effectiveness and safety of black cohosh (Cimicifuga racemosa or Actaea racemosa) for treating menopausal symptoms in perimenopausal and postmenopausal women.

Search methods

Relevant studies were identified through AARP Ageline, AMED, AMI, BioMed Central gateway, CAM on PubMed, CINAHL, CENTRAL, EMBASE, Health Source Nursing/Academic edition, International Pharmaceutical Abstracts, MEDLINE, Natural medicines comprehensive database, PsycINFO, TRIP database, clinical trial registers and the reference lists of included trials; up to March 2012. Content experts and manufacturers of black cohosh extracts were also contacted.

Selection criteria

All randomised controlled trials comparing orally administered monopreparations of black cohosh to placebo or active medication in perimenopausal and postmenopausal women.

Data collection and analysis

Two review authors independently selected trials, extracted data and completed the 'Risk of bias' assessment. Study authors were contacted for missing information.

Main results

Sixteen randomised controlled trials, recruiting a total of 2027 perimenopausal or postmenopausal women, were identified. All studies used oral monopreparations of black cohosh at a median daily dose of 40 mg, for a mean duration of 23 weeks. Comparator interventions included placebo, hormone therapy, red clover and fluoxetine. Reported outcomes included vasomotor symptoms, vulvovaginal symptoms, menopausal symptom scores and adverse effects. There was no significant difference between black cohosh and placebo in the frequency of hot flushes (mean difference (MD) 0.07 flushes per day; 95% confidence interval (CI) -0.43 to 0.56 flushes per day; P=0.79; 393 women; three trials; moderate heterogeneity: I2 = 47%) or in menopausal symptom scores (standardised mean difference (SMD) -0.10; 95% CI -0.32 to 0.11; P = 0.34; 357 women; four trials; low heterogeneity: I2 = 21%). Compared to black cohosh, hormone therapy significantly reduced daily hot flush frequency (three trials; data not pooled) and menopausal symptom scores (SMD 0.32; 95% CI 0.13 to 0.51; P=0.0009; 468 women; five trials; substantial heterogeneity: I2 = 69%). These findings should be interpreted with caution given the heterogeneity between studies. Comparisons of the effectiveness of black cohosh and other interventions were either inconclusive (because of considerable heterogeneity or an insufficient number of studies) or not statistically significant. Similarly, evidence on the safety of black cohosh was inconclusive, owing to poor reporting. There were insufficient data to pool results for health-related quality of life, sexuality, bone health, vulvovaginal atrophic symptoms and night sweats. No trials reported cost-effectiveness data. The quality of included trials was generally unclear, owing to inadequate reporting.

Authors' conclusions

There is currently insufficient evidence to support the use of black cohosh for menopausal symptoms. However, there is adequate justification for conducting further studies in this area. The uncertain quality of identified trials highlights the need for improved reporting of study methods, particularly with regards to allocation concealment and the handling of incomplete outcome data. The effect of black cohosh on other important outcomes, such as health-related quality of life, sexuality, bone health, night sweats and cost-effectiveness also warrants further investigation.






閉経期および閉経後の女性を対象に、更年期障害の治療に対するブラック・コホッシュ(Cimicifuga racemosaoまたはActaea racemosa)の臨床的有効性および安全性を評価すること。


AARP Ageline、AMED、AMI、BioMed Central gateway、CAM on PubMed、CINAHL、CENTRAL、EMBASE、Health Source Nursing/Academic edition、International Pharmaceutical Abstracts、MEDLINE、Natural medicines comprehensive database、PsycINFO、TRIP database、臨床試験登録データベースおよび対象試験の参考文献リストから2012年3月までの関連研究を同定した。研究内容の専門家およびブラック・コホッシュ抽出物製造業者に問い合わせを行った。






閉経期および閉経後の女性計2027例を募集した16件のランダム化比較試験を同定した。いずれの研究でもブラック・コホッシュ単一製剤を経口投与し、1日用量中央値は40 mg、平均投与期間は23週間であった。対照介入はプラセボ、ホルモン療法、レッドクローバーおよびフルオキセチンであった。報告されたアウトカムは血管運動神経症状、外陰膣症状、更年期障害スコア、有害作用などであった。ブラック・コホッシュとプラセボの間でホットフラッシュの頻度(平均差[MD]0.07回/日、95%信頼区間[CI]-0.43〜0.56回/日、P = 0.79、参加者393例、試験数3件、中等度の異質性、I2 = 47%)および更年期障害スコア(標準化平均差[SMD]-0.10、95%CI -0.32〜0.11、P = 0.34、参加者357例、試験数4件、低い異質性、I2 = 21%)に有意差は認められなかった。 ホルモン療法は、ブラック・コホッシュと比較して1日あたりのホットフラッシュの回数(試験数3件、データは統合せず)および更年期障害スコア(SMD 0.32、95% CI 0.13〜0.51、P = 0.0009、参加者468例、試験数5件、きわめて高い異質性、I2 = 69%)を有意に低下させた。 研究間に異質性が認められるため、これらの知見は慎重に解釈すべきである。 ブラック・コホッシュと他の介入の有効性を比較した結果、結論に達しない(きわめて高い異質性または研究数の不足が原因)かまたは統計学的有意差が認められなかった。同様に、研究報告の質が劣っているため、ブラック・コホッシュの安全性に関する決定的なエビデンスは得られなかった。データが不足していたため、健康に関連した生活の質、性的能力、骨の健康、外陰膣萎縮症および寝汗に関する結果を統合できなかった。いずれの試験でも費用対効果に関するデータは報告されていなかった。研究報告が不十分であったため、対象試験の質は概して不明であった。




《注意》この日本語訳は、臨床医、疫学研究者などによる翻訳のチェックを受けて公開していますが、訳語の間違いなどお気づきの点がございましたら、eJIM事務局までご連絡ください。なお、2013年6月からコクラン・ライブラリーのNew review, Updated reviewとも日単位で更新されています。eJIMでは最新版の日本語訳を掲載するよう努めておりますが、タイム・ラグが生じている場合もあります。ご利用に際しては、最新版(英語版)の内容をご確認ください。

Plain language summary

Black cohosh (Cimicifuga spp.) for menopausal symptoms

Menopause is the period of time in a woman's life when menstruation ceases. These changes in menstruation are often accompanied by troublesome symptoms, including hot flushes, vaginal dryness and night sweats. Interventions that decrease the severity and frequency of these menopausal symptoms are likely to improve a person's well-being and quality of life. The herb black cohosh was traditionally used by Native Americans to treat menstrual irregularity, with many experimental studies indicating a possible use for black cohosh in menopause. This review set out to evaluate the effectiveness of black cohosh for controlling the symptoms of menopause. The review of 16 studies (involving 2027 women) found insufficient evidence to support the use of black cohosh for menopausal symptoms. Given the uncertain quality of most studies included in the review, further research investigating the effectiveness of black cohosh for menopausal symptoms is warranted. Such trials need to give greater consideration to the use of other important outcomes (such as quality of life, bone health, night sweats and cost-effectiveness), stringent study design and the quality reporting of study methods.





《注意》この日本語訳は、臨床医、疫学研究者などによる翻訳のチェックを受けて公開していますが、訳語の間違いなどお気づきの点がございましたら、eJIM事務局までご連絡ください。なお、2013年6月からコクラン・ライブラリーのNew review, Updated reviewとも日単位で更新されています。eJIMでは最新版の日本語訳を掲載するよう努めておりますが、タイム・ラグが生じている場合もあります。ご利用に際しては、最新版(英語版)の内容をご確認ください。