en تخصصي Special پژوهشي Research Objective: There are some studies about the good effects of herbal medicine on blood glucose. This study was designed to evaluate the synergism effect of Peganum Harmala (P.harmala), Quercus Infectoria (Q.i), Vaccinium Myrtillus (V.myrtillus), Citrullos Colocynthis (C.colocynthis), Securigera Securidaca (S.s) on blood glucosein type 2 diabetic patients. Materials and Methods: Twenty four type 2 diabetic patients were enrolled in this cross over double- blinded clinical trial for receiving two months herbal medication and placebo. The subjects divided into two groups randomly. One group received herbal medication (the doses of 25mg/person of V.myrtillus, S.s and Mazoj and 62.5mg C.colocynthis, P.harmala) and the other group received placebo for 8 weeks. After washout period the herbal medication and placebo were replaced for the next 8 weeks. T-test and Chi-square were used for the comparison of variables between two groups. Results: After two months, mean fasting blood glucose was 135±27.1 and 139±36.8 mg/dl, (P-value=0.64), and mean glycosylated hemoglobin was 6.5±0.75 and 6.6±0.97 percent, with herbal medication and placebo, respectively (P-value=0.51). About 15.4%of patients after herbal medication and 15.4 % after placebo consumption had 0.8% reduction in HbA1C (P-value=1/0). The mean HOMA IR index, after two months intervention with herbal medication or placebo, was 2.9±1.95 and 3.9±1.97, respectively (P-value=0.05). Conclusion: low dose combination of P.harmala, Q.i, V.myrtillus, C.colocynthis, S.s improve the insulin sensitivity.Also low dose of this combination did not have significant effect on blood glucose. Diabetes mellitus, Herbal medication, Insulin sensitivity, Glycosylated hemoglobin 67 73 http://ijdo.ssu.ac.ir/browse.php?a_code=A-10-30-75&slc_lang=en&sid=1 Zahra Kashi No Endocrinologist, Associate Professor, Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran and Traditional and Complementary Medicine Research Center, Mazandaran University of Medical Sciences , Khadijeh Rabiei No Traditional and Complementary Medicine Research Center, Mazandaran University of Medical Sciences Sari, Iran Seyyed Saeid Mosavidarka No Mazandaran University of Medical Sciences Sari, Iran Adele Bahar Yes Endocrinologist, associate professor, Traditional and Complementary Medicine Research Center, Mazandaran University of Medical Sciences ,Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran. Ozra Akha No Endocrinologist, Associate Professor, Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran and Traditional and Complementary Medicine Research Center, Mazandaran University of Medical Sciences , Mohammad Karami No Associate Professor of Basic Toxicology, School of Pharmacy-Department of Toxico Pharmacology, Mazandaran University of Medical Sciences, Sari, Iran.