Materials and Methods: In this double-blind placebo-controlled trial, 60 students with moderate or severe dysmenorrhea were randomly allocated to two intervention groups and one control group (receiving 150 mg and 300 mg magnesium stearate, or placebo from the 15th day of menstruation until the following cycle, respectively). All participants reported their menstrual symptoms according to the Symptom Severity Scale 2 cycles before and 2 cycles after the intervention. The main outcomes included menstrual symptoms such as cramps, headache, foot pain, depression, irritability, general pain, and abdominal pain.

Results: According to the results, although both doses of magnesium could significantly reduce all symptoms of dysmenorrhea compared to the placebo (P < 0.001), magnesium 300 mg was more effective in decreasing symptoms such as cramps, headache, back pain, foot pain, depression, irritability, and abdominal pain.

Conclusions: The results showed that both doses of magnesium stearate (150 and 300 mg) can reduce severity of menstrual symptoms although the effect was greater with magnesium stearate 300 mg.