The effect of mixed onion pills on body composition, blood pressure, and concentrations of blood glucose and lipids were studied in 10 men ($38.11{pm}2.82$ years old). The mixed onion pills was produced by mixing quercetin, onion, mulberry leaves and buckwheat. Ten volunteers (male, BMI 23.0~35.4 kg/$m^2$) were chosen for this study. The volunteers consumed 1.2 g of mixed onion pills (containing about 30 mg of quercetin) per day for 2 months. The administration of the mixed onion pills did not produce any weight and BMI changes in the subjects. The systolic blood pressure and the level of blood glucose were slightly lowered by the supplementation of the mixed onion pills. After 2 months both the concentration of plasma triglycerides and total cholesterol of the subjects were lowered by 12.4% and 5.0%, respectively (triglyceride; pre $251.67{pm}45.63$ mg/dL vs. post $220.44{pm}44.67$ mg/dL and total cholesterol; pre $207.25{pm}10.39$ mg/dL vs. post $196.63{pm}10.47$ mg/dL, p<0.05). These results suggest that the mixed onion pills may possibly lower the level of plasma lipids in overweight or obese men (BMI greater than 23 kg/$m^2$).