How Much Black Cohosh Can You Take In One Day?

Black cohosh is a perennial North American herb related to the buttercup. Preparations of the root are sold in the United States as dietary supplements and used in Europe to treat unpleasant symptoms associated with premenstrual syndrome and menopause. How much black cohosh you can take in one day depends on the formula and the condition it is intended to treat. However, always consult a physician experienced in the use of this herb for specific recommendations.

Black Cohosh Preparations

Black cohosh preparations are made using the rhizomes and roots of Cimicfuga racemosa. The "Physicians' Desk Reference for Herbal Medicines" lists the active constituents of the plant as a variety of triterpene glycosides. According to the Office of Dietary Supplements of the National Institutes of Health, or ODS, black cohosh extracts are standardized to contain 1 mg of total triterpenes in each 20 mg dose.

The most studied preparation is Remifemin, a commercial product that originally contained the equivalent of 20 g of root in each tablet, extracted by a 60 percent solution of ethanol. However, the manufacturer changed the extraction process by using a 40 percent solution by volume of isopropyl alcohol instead. This, says the ODS, makes it difficult to compare results between studies on the pharmacological effects of black cohosh extract.

Black Cohosh Effects

In the Nov. 1, 2007 issue of the International Journal of Cancer, researchers from Columbia University reported that actein activates certain transcription factors that induce apoptosis, or death, in human breast cancer cells with an exposure of 20 or 40 microg/mL for 6 or 24 hours.

The ODS cites a study that involved 60 women who underwent hysterectomies but kept one or both ovaries and were given either black cohosh extract or one of three estrogen therapies. The researchers found that a black cohosh extract equivalent to 8 mg of drugs per day, taken as 2 mg tablets, was as effective in reducing physical discomfort as the estrogen therapies.

Adult Dosage

According to the University of Maryland Medical Center, the most black cohosh you can take in one day as an adult is between 40 and 80 mg in the form of tablets or capsules standardized to contain 1 percent triterpene glycosides. This generally equates to two tablets or capsules in a 24-hour period.

If you're using black cohosh tincture, the maximum daily dose is 4 ml mixed with water or tea, taken three times per day.

Although not as effective as standardized preparations, a decoction of black cohosh may be made by simmering 20 g of the dried root in 32 oz of water for 30 minutes. Strain and store the decoction in the refrigerator for up to 48 hours. This strong tea may be taken in doses of 1 cup, three times a day.

Pediatric Dosage

Since the pediatric use of this herb has not been studied, black cohosh should not be given to children under the age of 12.

Safety Considerations

Side effects may include nausea, vomiting, diarrhea or dizziness. This herb should not be used during pregnancy since it may promote uterine contracts. In addition, there is evidence that black cohosh may stimulate growth in breast cancer cells despite reports to the contrary. Be sure to talk to your doctor before taking this herb if you have undergone or are being treated for a hormone-driven disease, such as breast cancer.