Students will be given a placebo exercise on a flat yoga/exercise mat on the same days, in the same way and for the same duration as the intervention group.

They will be asked to lie on the acupressure mat for 15 minutes once a day, 3 days a week (Monday, Wednesday, Friday). A reminder message will be sent on the morning of the application so that participants do not forget and are motivated. After each application, participants will be asked to fill out the session monitoring chart.

The Premenstrual Syndrome Scale will be applied and the scale results will be evaluated. Participants who score 132 and above on the scale will be considered to be experiencing PMS. The intervention will be made in the second phase of the study.This practice will continue for three menstrual cycles.

It was developed by Gençdoğan (2006) to measure the severity of premenstrual symptoms. The scale consists of 44 questions that measure the severity of premenstrual symptoms based on DSM-III and DSM-IV-R. It is a five-point Likert-type scale. In the scoring of the scale, the option "Never" is given 1 point, the option "Very little" is given 2 points, and the option "Sometimes" is given 3 points.

The scale was developed by Cohen et al. in 1983 to measure the stress a person perceives in a given situation and was adapted to Turkish by Eskin et al. (2013). The 5-point Likert-type scale (Never (0)-Very often (4)) contains a total of 14 items. 7 items with positive expressions are scored in reverse. The minimum score from 0 to a maximum of 56 points can be obtained from the scale. A high score indicates that the person is highly stressed.

Students will be asked to evaluate their sleep quality with the Visual Analog Scale. VAS-sleep quality is a 10 cm long tool. "My sleep quality is very poor" is written on the left end of the scale and "My sleep quality is very good" is written on the right. A score of 10 from the scale indicates that sleep quality is high, while a score of 0 indicates that sleep quality is very poor.