Black Cohosh has definitely been shown to improve the sense of well-being at menopause. Whether or not black cohosh will be shown to protect the bones and heart is still uncertain. Typical doses include 250-500 mg of the dry powder extract three times a day. Or you can use 20-40 mg of the standardized extract twice a day. Do not confuse black cohosh with blue cohosh.
Blue cohosh is potentially toxic.
This is not a natural hormone replacement like phytoestrogens. Menopause is complicated. Physical changes from estrogen loss are mixed with psychosocial changes from empty nest syndrome, fear of aging, and other common daily occurrences. If you want to help yourself, concentrate on protecting your bones and heart and avoid useless products that have not been proven to be either effective or safe. Hot flashes are very annoying and can usually be treated with or without hormones.