Background & Aim: Premenopausal syndrome affects daily activities of many women. This study aimed to compare the effects of Vitexagnus and Flaxseed on premenstrual symptoms in women referred to health centers of Tabriz from October 2013 to September 2014 .

  Methods & Materials: This randomized controlled trial was conducted among 159 women suffered from premenstrual syndrome (PMS). The PMS was measured using the premenstrual assessment form (PAF) . The participants were allocated into three groups (n=53 per group) using block randomization. The group I received 25 grams/d Flaxseed powder and placebo of the Vitexagnus group II received 3.2-4.8 mg/d Vitexagnus tablets and placebo of the Flaxseed and the control group received both placeboes. The PAF was completed at baseline and 1 and 2 month after the intervention. Data were analyzed using the general linear model . 

  Results: The PMS improved significantly in both intervention groups during the first and the second month after the intervention. In the Vitexagnus and Flaxseed groups, the mean total PMS score were significantly lower than that in the control group at the first months after the intervention (adjusted mean difference: -3.3 (95% CI: -4.0 to -2.1) -4.3 (-5.5 to -3.0), respectively). In the second month after the intervention, the mean total PMS score was -5.8 (-7.0 to -4.7) in the Vitexagnus group and -6.6 (-8.1 to -5.7) in the Flaxseed group. There was no significant difference between the Vitexagnus and Flaxseed groups in terms of the PMS score .

  Conclusion: According to the results of this study, Flaxseed and Vitexagnus are effective in improving PMS .