A study appearing in Zentralblatt für Gynäkologie (1989;111:755-760) looked at 50 women with primary dysmenorrhea. The women were randomly divided and received either magnesium supplementation or a placebo for six months. At the end of the study, 21 of the 25 supplemented women demonstrated a reduction in symptoms. Magnesium may reduce the production of prostaglandin F2a, a substance which may be responsible for the symptoms of dysmenorrhea. The subjects receiving the magnesium had 45% less prostaglandin F2a in the menstrual blood. Other research appearing in the German medical journal, Schweizerische Rundschau für Medizin Praxis (April 17, 1990;79(16):491-494) looked at the effect magnesium supplementation had on dysmenorrhea. The subjects in the double-blind trial were 32 patients suffering with dysmenorrhea, between the ages of 16 and 42. The women were randomly divided to receive either a placebo or a dose of magnesium for three days, beginning on the day before menstruation. There was little difference in symptomatology between the two groups on the first day. On the second and third day, however, the magnesium group experienced less back pain, lower back pain or other symptoms.

An article appearing in Clinical Obstetrics and Gynecology (1978;21(1):139-145) discusses the role of prostaglandin F2a and how it increases the amplitude and frequency of uterine contractions—creating cramping. This is demonstrated by the fact that when injected, prostaglandin F2a can produce uterine cramping. The author of the study recommends a combination of magnesium and vitamin B6 to treat dysmenrrhea. He notes that when B6 is given alone, it can increase the magnesium content of red blood cells, because B6 increases the influx of magnesium into the cell. The combination of these two nutrients can reduce the intensity and duration of menstrual cramps.