This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Emmenagogues are medicinal substances which promote the menstrual discharge, or restore it when entirely suppressed. The particular emmenagogue required depends upon the cause of the amenorrhea; for example, when anemia is the cause, the preparations of iron prove most effectual; when from plethora, blood letting and cathartics or evacuants are resorted to. Certain medicinal substances excite the pelvic circulation, and stimulate the parts in direct connection with the uterus, and thereby increase or promote the menstrual discharge.