How does black cohosh work to relieve menopause symptoms?

Black cohosh's exact mechanism remains under investigation, though it is believed to act on serotonin receptors rather than estrogen receptors. Research suggests compounds like triterpene glycosides may modulate neurotransmitters involved in thermoregulation. Unlike phytoestrogens, it does not appear to stimulate breast tissue, making it distinct from hormonal therapies (Evidence Level: B).

Can black cohosh interact with medications or hormone therapy?

Black cohosh may interact with hormone-sensitive conditions and medications metabolized by the liver. It is contraindicated for patients with hormone-sensitive cancers or those taking CYP450 substrates due to potential liver enzyme interactions. Patients on anticoagulants or hormone replacement therapy should consult a physician before use (Evidence Level: C/D).

What is the recommended dosage for black cohosh extract?

The standard adult dosage for black cohosh is 20 to 40 mg of a standardized extract (containing triterpene glycosides) taken twice daily. Clinical studies often utilize specific extracts like Remifemin. Users should not exceed recommended durations without medical supervision, typically limiting use to six months (Evidence Level: B).

Is black cohosh safe to take during pregnancy or breastfeeding?

Black cohosh is considered unsafe during pregnancy because it can stimulate uterine contractions and induce labor. While traditionally used for this purpose near term, it should be avoided earlier in pregnancy to prevent miscarriage. It is also not recommended during breastfeeding due to insufficient safety data and potential toxicity to the infant (Evidence Level: C/D).

Is black cohosh effective for treating hot flashes and night sweats?

Clinical studies suggest black cohosh may reduce the frequency and severity of hot flashes and night sweats associated with menopause (Evidence Level: B). While results have been mixed, meta-analyses often show modest benefits compared to placebo. It is considered one of the most researched herbs for menopausal symptom management, though individual responses vary significantly.

Black Cohosh (Actaea racemosa)

What is a herb–drug interaction?

A herb–drug interaction happens when a plant or supplement changes how a medication works in your body — making it stronger, weaker, or more likely to cause harm. Herbs contain active compounds that can speed up or slow down the enzymes and transporters your body uses to process drugs.

Why it matters

St. John's Wort can make birth control, antidepressants, and blood thinners less effective.

Garlic can increase bleeding risk with warfarin and other blood thinners (also ginkgo, ginger, and turmeric).

Kava can amplify sedation when taken with anxiety or sleep medications (also valerian).

The risk is highest for older adults, anyone taking several medications, and people with chronic conditions.

Always tell your doctor and pharmacist about every herb and supplement you take — and check below before combining.

Known Drug Interactions (2)

2 Moderate

Drug	Severity	Description
Tamoxifen	Moderate	Black cohosh may interact with tamoxifen in hormone-sensitive conditions. The nature of interaction is uncertain.
Hepatotoxic medications (general)	Moderate	Black cohosh has been associated with rare cases of liver damage. Combining with other hepatotoxic drugs may increase liver injury risk.

This list reflects a curated subset of documented interactions and is not exhaustive. The absence of a drug here is not proof that it is safe to combine. Always confirm with a pharmacist or healthcare provider.

PubMed-compiled information sheet

This sheet was compiled from PubMed (NIH) abstracts using AI assistance. Every factual claim is cited to a real PubMed article (see the source list). It has not yet been human-reviewed — confirm with a healthcare provider before use.

Compiled from 25 PubMed articles · model: gemma4:31b

Summary

Black cohosh (Actaea racemosa) is a North American botanical supplement primarily used to manage menopausal symptoms [PMID:29261886, PMID:31643322].

Background

Black cohosh, also known as Cimicifuga racemosa, is a perennial dicot of the Buttercup (Ranunculaceae) family native to the Eastern United States and Canada [PMID:29261886, PMID:33861455]. It is also referred to as baneberry, black snakeroot, bug root, and bugbane [PMID:29261886].

Traditional uses

Historically, it has been used by indigenous populations for rheumatoid muscular pain, headache, inflammation, dysmenorrhea, premenstrual syndrome (PMS), and menstrual pain and cramping [PMID:33861455, PMID:22504147]. It has also been used to promote labor [PMID:30000840].

Active compounds

The rootstock contains triterpene glycosides (including actein, cimicifugoside, and 27-deoxyactein), isoferulic acid, and alkaloids such as n-methylcytisine [PMID:30000840, PMID:18592868].

Mechanism of action

While historically thought to have estrogenic activity, recent studies suggest it does not bind to estrogen receptors and lacks estrogenic effects on mammary cancer cells in vitro or uterine histology in rats [PMID:30000840, PMID:23459142]. Some research suggests it may act as an antinociceptive agent [PMID:22504147].

Clinical evidence

Evidence AMenopausal symptoms (neurovegetative and psychological)

Isopropanolic extract (iCR) was significantly superior to placebo and comparable in efficacy to low-dose transdermal estradiol or tibolone, with a better benefit-risk profile than tibolone [PMID:33021111].

Evidence BMenopausal symptoms (combined therapy)

A combination of Black Cohosh, Soy Isoflavones, and SDG Lignans showed significant improvements in somatic, psychological, and urogenital domains compared to placebo [PMID:40131516].

Evidence CClimacteric complaints

The extract CR BNO 1055 reduced major climacteric complaints as effectively as conjugated estrogens and significantly more than placebo [PMID:23459142].

Evidence AHot flashes in breast cancer patients

Research assessing efficacy for the treatment of hot flashes in women with breast cancer is inconclusive [PMID:17602247].

Safety & adverse effects

General adverse reactions are low in frequency but may include dizziness, nausea, headache, rash, vomiting, mastalgia, and weight gain [PMID:30000840, PMID:15898823]. Rare but severe reports of acute liver injury, hepatitis, and allergic reactions have occurred [PMID:30000840, PMID:31643322].

Pregnancy & lactation

Historically used by Native American women as a galactogogue, but there is no current data on safety and efficacy in nursing mothers or infants; some sources recommend against use during breastfeeding due to lack of safety data [PMID:30000840].

Drug interactions

Black cohosh is reported to have a low likelihood of drug interactions and can generally be safely taken with most medications [PMID:28762712].

Dosage & administration

One review notes a current recommended dosage of 40-80 mg/day for certain extracts [PMID:15898823]. No PubMed data available. Consult a healthcare provider.

Evidence summary

Evidence for the treatment of menopausal symptoms is supported by meta-analyses and RCTs, though some reviews describe findings as inconsistent or methodology as poor. Safety is generally high for short-term use, though rare hepatotoxicity is noted.

PubMed sources

1.PMID: 28762712 (2017) — Common Herbal Dietary Supplement-Drug Interactions. · American family physician
2.PMID: 39477563 (2024) — Complementary and Alternative Medicine for Menopause. · The Nursing clinics of North America
3.PMID: 30000840 (2006) — Exploring the Efficacy and Safety of Black Cohosh (Cimicifuga racemosa) in Menopausal Symptom Management. · Journal of mid-life health
4.PMID: 31643322 (2012) — Botanicals and Their Bioactive Phytochemicals for Women's Health. · CITED REFERENCES
5.PMID: 29261886 (2026) — Black cohosh. · American family physician

Black Cohosh

Sources & Citations

Dong Quai

Red Clover

Vitex

⚠️ Not Recommended During Pregnancy or Nursing

2 Known Drug Interactions — Some May Be Serious

Contraindications

Possible Side Effects

What is a herb–drug interaction?

Known Drug Interactions (2)

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Pregnancy & lactation

Drug interactions

Dosage & administration

Evidence summary

PubMed sources

Government sources

Black Cohosh

Sources & Citations

Related Herbs

Dong Quai

Red Clover

Vitex

⚠️ Not Recommended During Pregnancy or Nursing

2 Known Drug Interactions — Some May Be Serious

Contraindications

Possible Side Effects

What is a herb–drug interaction?

Known Drug Interactions (2)

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Pregnancy & lactation

Drug interactions

Dosage & administration

Evidence summary

PubMed sources

Government sources