A double-blind controlled crossover study to investigate the efficacy of salix extract on primary dysmenorrhea

Objectives: Primary dysmenorrhea in the absence of pelvic pathology is a common gynecologic disorder affecting the quality of life of women of reproductive age. This study evaluates the effect of salix extract on primary dysmenorrhea. Design: This study was a randomized crossover clinical trial. Setting: The study population included 96 female students with level two or three of primary dysmenorrhea: 48 students in the treatment group (sequence I) followed by control (sequence II) and 48 students in control group (sequence I) followed by treatment (sequence II). Interventions: The intervention was salix capsule (400 mg daily) and the active control was mefenamic acid capsule (750 mg daily) as. Main outcomes: Pain intensity, measured by the visual analog scale (VAS), amount of bleeding, and severity of dysmenorrhea symptoms were outcomes. Generalized estimating equations were used for data analysis. Results: The demographic and menstrual characteristics of the students were homogenous between the groups. The results showed that the students in mefenamic acid group had a significantly higher level of VAS than the students in the salix group over time (1.61 +/- 0.06, P < 0.001). The estimated odds of the bleeding level in the salix and mefenamic acid group were not significantly different (P = 0.31). In average, 77.39% +/- 16.18 of the students in salix group showed no symptoms followed by 22.18% +/- 14.08 of the students who experienced mild symptoms. Averagely, 44.58% +/- 20.16 of the students in the mefenamic acid group had mild symptoms followed by moderate symptoms (28.12% +/- 15.29). Conclusions: Salix extract significantly decreased dysmenorrhea in comparison to mefenamic acid, as the standard treatment of dysmenorrhea.