This study evaluates the time-dependent effects of EPA-PL from Cucumaria frondosa on lipid metabolism. EPA-PL strongly suppresses the hepatic TG accumulation (3 days) and the white adipose tissue mass (7 days). The mechanism of EPA-PL relies on upregulation of the β-oxidation in the liver and WAT. EPA-PL group remains higher hepatic DHA concentration during reversal.