Objectives: The objective of this study is to demonstrate the effect on blood lipids in humans, of a supplement which contained peptides and amino acids originating from oyster meat. Methods: Proteins in oyster meat were hydrolyzed by enzymes, followed by preparing oyster meat extract powder containing the peptides and free amino acids as a supplement. We performed the following 2 clinical trials in which male and female adults with dyslipidemia received the oyster meat supplement for specified periods; in the first open label trial, the oyster meat supplement was given to 14 subjects (average age 48.7 years old) for 8 weeks, while in the second crossover controlled trial, the oyster meat supplement and its placebo were taken by 19 subjects (average age 52.4 years old) for 4 weeks, respectively. In these trials, the effect of the supplement on blood lipids was evaluated by conducting serum chemistry and body composition measurement before and after taking the supplement. Results: In the open label trial, at the end of Week 4 from the start of taking the supplement, a decrease of very low-density lipoprotein (VLDL) and an increase of high-density lipoproteins (HDL) in blood lipoproteins were observed with statistically significant difference (P<0.01). In the crossover placebo-controlled study, we confirmed the reduction of the ratio of VLDL in lipoproteins (P=0.04), the increase of HDL cholesterol (P=0.02), and the suppression of the elevation of triglycerides (TG) (P=0.02) Week 4after the start of taking of the supplement. Conclusion: The oyster meat extract powder was most likely to have potential utilities in the management of dyslipidemia.