The Effect of Magnesium Sulfate on Pain Intensity and Menstrual Blood Loss in Students With Primary Dysmenorrhea: A Randomized Controlled Trial

No evidence exists for the lowest effective dose of magnesium on menstrual pain.

To determine and compare the effects of two different doses of magnesium on pain intensity and menstrual blood loss in students with primary dysmenorrhea.

Sixty dysmenorrhea patients were randomly assigned to one of two therapeutic groups and one placebo group (receiving one tablet a day of 300 or 150 mg magnesium sulphate or placebo from the 15th cycle day until no pain existed on the following cycle). Visual analogue scale (VAS) and Hjgham collected data for two cycles before and two cycles after the intervention. The data were analyzed using one-way ANOVA and ANCOVA tests. 

No significant difference was observed between the groups in terms of baseline characteristics. Both intervention groups outperformed the placebo group in terms of pain intensity (adjusted differences of -2.9, 95% confidence intervals of -3.3 to -2.4 and -1.9, -2.4 to -1.5, respectively) and menstrual bleeding (-20.0, -26.0 to -14.0, and -13.0, -19.0 to -7.0, respectively), as well as the secondary outcome, i.e. rest duration and ibuprofen consumption. In terms of pain alleviation and menstrual bleeding, participants in the 300 mg magnesium group outperformed those in the 150 mg magnesium group. No significant difference was observed between intervention groups regarding secondary outcomes.

Both magnesium levels are useful in alleviating pain and reducing menstrual bleeding, although 300 mg of magnesium was more effective.