This is all greatly exagerrated. The medical profession will tell you the herbs are drugs. Or that they make drugs out of herbs so the herbs are really drugs and they are dangerous. This is meant to scare people into not taking herbs. And it works very well with many people.
The side effects that are described in that site are greatly exaggerated. If it was that dangerous, there would be warnings in the quality health sites, such as Dr. Mercola, and there are none.
"Black cohosh can depress heart rate, anyone with any type of heart disease should not use this herb. Other possible side effects include dizziness, diarrhea, nausea, headaches, shakes, low pulse, vomiting."
As I said in my last post, this can happen only if Black Cohosh is taken in conjunction with prescription drugs that interefere with it or if taken in extreme doses. And it should not be taken if pregnant, or breastfeeding. I have never heard of the other side effects you mention at all.
Furthermore, I know ladies, and I am one of them, that did not need to take black cohosh for a very long period of time at all. It seemed to get rid of my hot flashes for good, as with other friends I have. I do not know if this is common in other women.