This study was performed to figure out the effects of I-razin in overweight children without any exercise or specific diet. Methods Twenty-eight children those who were diagnosed overweight have been recruited. They were randomly assigned treatment or control group under block randomization. Treatment group were treated with I-razin for 8 weeks, and control group were treated with placebo medication under same conditions. Anthropometry, fat computed tomography and blood test have been done before and after the treatment. Results Eleven subjects in treatment group and seventeen in control group were evaluated. BMI, waist circumference, glucose, total cholesterol, and triglyceride were decreased in the treatment group. And reduction of BMI, glucose, and triglyceride in the treatment group were greater than control group. But there was no statistically significance. No side effects have been notice during the study period and no adverse effect on liver has been observed. Conclusion This study could not demonstrate effect of I-razin compared with control group. However, treatment group has a tendency of weight loss without side effect. Additional studies with large population are thought to be necessary to clarify the effect of I-razin.