In the early 1960s many medical reports (although not controlled clinical trials) involving over 1,400 women were published in Germany. Health care practitioners documented benefits in premenopausal and menopausal symptoms including reduction in hot flashes and improvement of "depressive moods."

Furthering the advancements, five clinical studies since 1979 have compared Black Cohosh extracts with placebo and estrogen replacement in the treatment of menopausal symptoms. One study that was done in several clinics with information on 629 patients reported favorable results in more than three quarters of the participants after six to eight weeks of treatment. Improvements included relief of stereotypical problems: hot flashes, sweating, headache, dizziness, and rapid heartbeat. Some side effects that were not documented were reported in less than 10% of participants, but were not significant enough to stop taking.

Black Cohosh was actually introduced into medicine by Native Americans, who placed a high value on it. American Indians boiled the roots in water and drank the beverage for a variety of conditions ranging from rheumatism, diseases of women, and the pain of sore throats. It's subsequently used, especially by the Indian medicine man, for all these conditions but mostly for so-called uterine difficulties (regularity of cycles).

Scientific studies have shown that a methanol extract of black cohosh contains substances that bind to estrogen receptors of rat uteri. Cohosh extract also causes a selective reduction in luteinizing (luetinizing is a female hormone produced by the anterior lobe of the pituitary gland) hormone levels in rats. These results are generally universally interpreted to mean that this herb possesses some degree of estrogenic (stimulating and leveling) power.

A 1991 study confirmed an LH secretion inhibitory effect in both ovariectomized rats and in 110 menopausal women, demonstrating that the extract selectively suppresses luteinizing hormone secretion in menopausal women.

A recent Asian study reported positive effects of two Asian Cohosh species, on calcium and phosphate levels plus bone mineral density in rats. The findings concluded that these extracts have potential for the treatment of osteoporosis, particularly in menopausal women. It is recommended in Europe for various conditions, including symptoms associated with premenstrual syndrome (PMS), dysmenorrhea, and menopause. Reported activities include an estrogen-like action, binding to estrogen receptors, and suppression of luteinizing hormone. Occasional stomach pain or intestinal discomfort has been reported.

In North America, it is thought that Black Cohosh balances estrogen by stabilizing it. In European herbalism it is thought to have an estrogenic action, which actively works to reduce progesterone and promote estrogen levels in the body. It is therefore used where there is a lack of estrogen and an excess of progesterone. In the musculoskeletal system it is used as an anti-inflammatory in arthritic conditions. Its sedative qualities have applications in other systems, for example in lowering blood pressure, in reducing spasm and tension, and in the respiratory system.

Native Americans used the rhizome of this cohosh as a cure for rattlesnake bites (hence its common name, rattle root) and for menstrual and labor pain. The root was also chewed as a sedative and to alleviate depression. A tea made with the herb was sprinkled in rooms to prevent evil spirits from entering. In herbalism, the root is still used as a diuretic, a cough suppressant, and to reduce inflammation and rheumatic pain.

Black Cohosh is native to Canada and the eastern states of the US, growing as far south as Florida. This herb prefers shady spots in woods and shrubby areas. The herb is now grown in Europe and can be found in the wild, having self-seeded from cultivated plants. It is grown from seed, and the root is harvested in autumn.

Female applications - Native Americans have long used Black Cohosh for female problems, for which it was also known as "squawroot." It is used today for menstrual pain and problems where progesterone production is too high and for menopausal symptoms, especially hot flashes, debility, and depression.

Inflammation - Black Cohosh is useful for inflammatory arthritis, especially when it is associated with menopause, and it is also an effective remedy for rheumatic problems, including rheumatoid arthritis.

Sedative properties - the sedative action makes it valuable for treating a variety of conditions, including high blood pressure and tinnitus (ringing in the ears). It is also valuable for whooping cough and asthma. More and controlled studies are warranted on Black Cohosh. A health care practitioner should be consulted prior to administering any herbal products.