Background: Cinnamomum zeylanicum J. Presl (cinnamon) have been used as food and herbal drug in Asia and Europe. Although some studies have been shown that cinnamon has blood glucose lowering effect but some reports denied it.

Objective: This study was designed to investigate the efficacy of cinnamon on blood glucose level in patients with type 2 diabetes.

Methods: This study was a double blind randomized controlled trial study. 61 type 2 diabetic patients with fasting blood glucose of 140 to 250 mg/dl were randomly divided in to two groups. The patients in cinnamon groups received two 500mg cinnamon capsules and patients in placebo group received two 500mg placebo capsules daily.

  The patients fasting blood glucose, HbA1c, cholesterol, triglyceride, LDL and HDL were determined at starting and after 8 weeks at the end of the study.

Results: There was no significant difference in patients fasting blood glucose, HbA1c, cholesterol, triglyceride, LDL and HDL between intervention groups compared with placebo on starting of the trial. Further results indicated that there were no significant difference between two groups regarding lowering of blood glucose, HbA1c, and blood lipids after 8 week of cinnamon and placebo treatment.