"Possibly one of the best uterine nervines, Crampbark is remarkably effective for relaxing the uterine muscles. It is among my favorite remedies for menstrual cramps. I've also found it invaluable in cases of threatened miscarriage due to nerve stress and uterine tension. As Dr. John Christopher, one of the famous herb doctors of this century, writes in The School of Natural Healing, Crampbark is "possibly the best female regulator-relaxant that we have for the uterus and ovaries, and is especially useful for painful and difficult menstruation and for nervous afflictions during pregnancy that threaten abortion.
Rich in valerianic acid, the same constituent found in valerian, Crampbark's sedating and relaxing actions are specific to the reproductive system. A high tannin content makes it beneficial in cases of excessive menstrual bleeding. It is often recommended as a tonic and remedial herb for women who bleed excessively during their menstrual cycle. It is an invaluable herb for use during menopause by women who find themselves bleeding excessively due to changes in hormones. I've also found it helpful for women who have double menstrual cycles each month.
Though a strong medicinal herb, Crampbark can be safely used over an extended period of time. There are no known side effects or reported toxicities."