Background: Primary dysmenorrhea, sometimes with one or more systemic symptoms and is associated with severe bleeding. Objective: We conducted a double-blind randomized placebo controlled clinical trial to evaluate the impact of Valerian on the bleeding and systemic manifestations of menstruation. Methods: A total of 100 students were randomly assigned to treatment (51 subjects) or placebo group (49 subjects). The treatment was 255 mg of Valerian 3 times a day over 3 days at the onset of menstruation. Bleeding and systemic manifestations were evaluated with a menstrual pictogram and multidimensional verbal scale before and during 2 consecutive menstrual cycles respectively. Results: Statistical tests showed that severity and duration of bleeding between the two groups were not significantly different (p=>0.05).after treatment in two groups the mean total score for intensity of systemic than before treatment can be reduced (p <0.001), but this decreased statistically between valerian and placebo groups was not significant. Except on fainting variable intensity difference between groups was significant (p <0.05). Conclusion: This study showed that valerian doesn’t increase severity of bleeding and systemic manifestations. Valerian and placebo reduce severity of systemic manifestations but the difference between the two groups was not statistically significant. It seems more research is need. Valerian can reduce faint with dysmenorrheal.