The main aim of this study is to evaluate the effect of alfalfa (Medicago Sativa) on platelet counts in patients with idiopathic thrombocytopenic purpura. This study will be done as a randomized, double-blind, placebo-controlled, clinical trials phase 2 and single-center. 40 patients with ITP who would like to participate in the study and have the Inclusion criteria will be enrolled with convenience sampling and randomly will be divided into two groups of intervention and control. The intervention group will be received Medicago Sativa syrup and daily intake of patients is 5 ml every eight hours and the control group will be received placebo syrup 5 ml every eight hours for 15 days. Laboratory blood test for platelet count, CBC and BT will be done before and after the intervention. Inclusion criteria are definitive diagnosis of ITP by hematologist, aged 15-50 years with platelet count between 50,000 to 150,000, lack of spontaneous bleeding, lack of systemic diseases such as lupus erythematosus and other blood diseases. The patients with an active and spontaneous bleeding, thrombocytopenia below 50,000, need for hospitalization and pregnancy are excluded. The study intervention is Medicago Sativa syrup containing 650 mg of extract of alfalfa in each 5 ml and daily intake of patients is 5 ml every eight hours. The control group will be received placebo syrup 5 ml every eight hours. Variables for main outcomes are measurment of platelet count, CBC and BT before and after the intervention.