The study was conducted in a double-blind and randomization method using stratified random allocation, so that according to the severity of PMS, the patients were divided into three categories: very severe, moderate to severe, and mild, and in each category, they were randomly assigned to three groups A and B. and C were divided. A total of 204 female students living in the dormitory of Shahrekord University of Medical Sciences with PMS were divided in terms of physical symptoms and psychological symptoms, and as a result, 66 people were in the mild category, 84 people were in the moderate category, and 54 people were in the severe category. The random sequence was obtained through the online randomization program (program address:
https://www.sealedenvelope.com/simple-randomiser/v1/lists)
And based on the random list, each patient was assigned to one of the groups A, B, and C, respectively. In terms of the severity of premenstrual syndrome, in each group of 68 people, there were an equal number of 22 mild, 28 moderate and 18 severe patients. After filling the consent form, the drugs were prepared by a pharmacologist from Dr. Abedi Pharmaceutical Company and divided into three packages of the same color. And one shape was named with letters A, B and C. Group A contained 1000 mg of calcium, group B contained 300 mg of magnesium, and group C contained selenium as a placebo. The patients and the researcher did not know about the contents of the package.