Background & Objectives: Different types of diets and several chemical and herbal drugs are used for decreasing the fasting blood glucose, glycosylated hemoglobin and insulin resistance in type II diabetic patients. New herbal medicines including cinnamon have been considered for controlling diabetes. Since few reports have been presented in other countries and many studies have been done in animal models in laboratory condition, this study was aimed to investigate cinnamon supplementation effects on fasting blood glucose, glycosylated hemoglobin and insulin resistance among type II diabetic patients .

 Methods: In a clinical trial study, 60 male and female patients with type II diabetes mellitus (30 patients in control and 30 patients in treatment group) were selected in Tabriz city, during 1388. The intervention group received 1.5 g of cinnamon (as a capsule containing 500 mg powder, three times daily) for 60 days and control group received placebo. Blood samples obtained from patients to determine the levels of fasting blood glucose, the glycosylated hemoglobin and insulin, before and after cinnamon consumption. Insulin resistance was measured by HOMA score and data were expressed as Mean ± SD and analyzed statistically by Student t-test. p<0.05 was considered as significant .

 Results: After 60 days, the fasting blood glucose levels, the glycosylated hemoglobin and the insulin resistance decreased significantly in the intervention group compared to controls (p<0.05). There was no significant change in the fasting blood glucose levels, the glycosylated hemoglobin and the insulin resistance in the control group at the end of 60 days.

 Conclusion: This study showed the consumption of cinnamon can be useful in the fasting blood glucose, the glycosylated hemoglobin and the insulin resistance control among type II diabetic patients .