The volunteers are screened through medical history, physical exam, laboratory tests etc. within 4 weeks (-28d~-2d) prior to the day scheduled for taking the investigational product (1d). The final subjects determined eligible for this clinical trial through screening tests are randomized to the dose groups with Belviq 10 mg and 20 mg. Twelve subjects are assigned to each group (9 subjects to study drug and 3 subjects to placebo), and the study drug or placebo are administered to the corresponding administration group. The subjects are discharged on the morning of 4d after completing the set study schedule at 72 hours after administration. The subjects then visit for the final tests on the last out-patient visiting day. Belviq is progressed sequentially from the low-dose group to the high-dose group.