Others have tried the herbal preparation called black cohosh for hot flashes. There are only very few studies done regarding the safety and benefits of this option. All the same, the North American Menopause Society has recommended the short-term use of this herb for treating menopause. The North American Menopause Society did, however, recommend using black cohosh only up to six months at a time.
Interestingly, there was one large study call the Herbal Alternatives for Menopause Trial done to test the effectiveness of various kinds of herbal and alternative treatments. These were contrasted with not only estrogen but a placebo as well. The results revealed that these preparations, which included black cohosh, were no better than the placebo.
https://www.empowher.com/reproductive-system/content/are-alternative-or-natural-treatments-menopause-worth-it