Black Cohosh has been traditionally used to manage menopause symptoms such hot flashes, and preferred by many to hormone replacement therapy. Although the results of clinical studies are conflicting, its effectiveness has never been in question, and those that use it are convinced of its beneficial effects. While it does appear to exhibit weak estrogen properties more work is needed before a biochemical explanation for its effects can be firmly established.



Black cohosh, also known as black snakeroot and fairy candle, is a member of the ranunculaceae (buttercup) family, and is native to the eastern parts of North America. It prefers a woodland setting, and is frequently found in small open areas in woodland. The preparations are produced from the roots and rhizome of the plant. Its name is derived from the color of the rhizome, and the native Algonquian 'cohosh' referring to the roughness of the rhizome surface.

Native Americans have used black cohosh throughout history for the treatment of gynecological conditions and also various other disorders ranging from sore throats to depression, malaria, rheumatism and constipation. It has also been used as a home remedy for fever and also to promote menstruation, and has been prescribed by herbal therapists for infertility and inflammation of the womb and ovaries.

The way that it works is not fully understood, although it is believed to compensate for the estrogen loss that a woman suffers during menopause. Black cohosh contains phytoestrogens, which simply means that it contains plant derived estrogen substances, although it is not certain that is the mechanism by which it works. There is now some evidence that it acts by blocking serotonin receptors, including those that help to regulate body temperature. It is known that these are important in regulating the hot flashes experienced during menopause. This effect on serotonin receptors can also help to reduce depression and mood swings.

In spite of this lack of understanding, the active ingredients contained in black cohosh are known to be triterpene glycosides, particularly actein, 27-deoxyactein (23-epi-26-deoxyactein) and cimicifugoside. Non-terpenoid components include tannins, flavonoids, fukinolic acid, volatile oils and salicylic acid. Due to the presence of the salicylic acid, you should consult with your doctor before using black cohosh if you are also taking aspirin or herbs with blood thinning qualities such as gingko biloba and ginseng.

It has been established in Germany that black cohosh can give rise to a reduction in luteinizing hormone. Since hot flashes have been associated with sudden increases in this hormone, then this was believed to provide a method of measuring the effects of the herb. However, other studies have indicated no effect on luteinizing hormone, so the situation here is still obscure. In fact no single component was found to be responsible, and its effect is now believed to be due to a synergism of several of the components of the rhizome that compete with estradiol for the receptor protein binding sites.

Subsequent clinical studies have indicated black cohosh to be a suitable alternative to estrogen replacement therapy for the treatment of problems caused by the menopause. Its use within Europe and Asia is rising, and even in North America it is becoming more acceptable as a menopause treatment. It is used as a dietary supplement and so is not regulated by the FDA, and does not require proof that it will be effective or that it will be safe to anybody consuming it.

Although clinical studies are not conclusive, and although the herb appears to help reduce some of the symptoms of menopause and pre-menstrual syndrome (PMS), there are some relatively minor side effects. Among these are dizziness and vomiting, and black cohosh has also been known to cause a lowering of blood pressure. For that reason it should not be used by people under treatment for high blood pressure since their blood pressure could be lower below a safe level. It is also best not used by pregnant women since there is a possibility of it inducing a miscarriage due largely to its effect on luteinizing hormone.

Part of the reason why clinical studies have been unsuccessful in proving the effectiveness of black cohosh is that they have mainly been of short duration: generally six months or less. In addition to this, black cohosh suffers the same problem that most natural or herbal remedies face: doses were not standardized since the active ingredients were unknown. Different plant sources could have varying quantities of the identified active substances, and it was not known on which to standardize the dose. Although this is still a problem, standardization is now generally carried out on the terpene glycosides, particularly on the 27-deoxyactein content.

Although the side effects listed earlier have been experienced by patients who used black cohosh, there is no definite evidence that they were caused by the substance, and extensive testing has shown a low incidence of such effects. The main adverse effects reported in many studies have been headaches, stomach problems and weight problems. However, it is wise to seek expert medical advice when taking any herbal remedy, and it should be borne in mind that tests on black cohosh have been relatively short.

It is usually necessary to carry out tests over a period of years in order to establish long-term effects, and six months is certainly too short a period from which to draw a definitive conclusion. There have been no studies carried regarding the long term safety of the substance. Until its effects are better understood, pregnant women and those with breast cancer are advised not to use it.

Black cohosh has not been shown to have interactions with any other drugs, although there have been very few studies carried out to establish this. However, there are as yet no reasons to suggest a healthy person should not use it for the treatment of menopausal symptoms. The native Americans even used it to induce labor when the child was late in coming. The American College of Obstetricians and Gynecologists state black cohosh to be safe to use for at least six months. After that nobody knows, but here are a few cautionary words about its use:

1. Do not confuse black with blue cohosh. The latter is far more toxic and is an entirely different herb.

2. Do not use it if you are pregnant: its longer term effects on pregnant women are unknown so you are best to play it safe.

3. The same is true if you have breast cancer, or if there is breast cancer in your family. There is not enough evidence yet of its effects on breast tissue.

4. Be careful if you are a nursing mother: for the same reason as above.

5. Seek medical advice first if you are taking blood-thinning drugs such as aspirin.

Other than the above, black cohosh appears an excellent way to manage your menopause symptoms, although make sure that you are using a dose standardized on the terpene glycoside or the 27-deoxyactein content. Some might simply state a dose based upon Cimicifuga Racemosa and that too is acceptable.

Like all herbal extracts or remedies, the dose must be standardized or you have no way of knowing what you are purchasing.