Monascus Garlic Fermented Extract (MGFE) is a unique material produced from garlic fermented using Monascus pilosus, which contains characteristic compounds such as dimerumic acid and monacolin K. In this study, we examined the effect of MGFE on hyperlipidemic subjects. Fifteen subjects aged 33-59 years (11 men and 4 women) participated. All the subjects had either hypercholesterolemia (> or = 220 mg/dl) or hyper-low-density lipoprotein cholesterolemia (> or = 140 mg/dl), but only 4 of the 15 (27%) were hypertriglycemic (> or = 150 mg/dl). All subjects received two capsules of MGFE (225 mg/capsule) after breakfast and dinner for 4 weeks. After an overnight fast, blood was taken 0, 2 and 4 weeks after the start of MGFE intake, and 2 weeks after MGFE withdrawal. MGFE significantly reduced serum total cholesterol (TC) and low-density lipoprotein cholesterol levels 2 and 4 weeks after the start of MGFE intake as compared with the baseline. Although the level of high-density lipoprotein cholesterol (HDL-C) was unaffected at any time, the atherogenic index calculated from the value of TC and HDL-C was significantly reduced 2 and 4 weeks after the start of MGFE intake. These effects of MGFE tended to disappear within 2 weeks after withdrawal. Triglyceride (TG) and lipid peroxide levels were not reduced dramatically, but TG levels in hypertriglycemic subjects tended to reduce as compared with the baseline value. No abnormal changes in blood biochemical parameters or adverse effects were observed in any of the subjects. Our present results indicate that MGFE attenuates hyperlipidemia, suggesting that MGFE is a potent agent for preventing arteriosclerotic diseases.