The study is considered research because efficacy (how well a drug works) information is needed in healthy, 25-45 year-old, female subjects with moderate caffeine intake. The investigational product is available in the United States without a prescription (over-the-counter) as a nutritional supplement. The purpose of this study is to assess whether One-A-Day Weightsmart Advanced is safe and can increase metabolism and perceived energy in female subjects compared with caffeine or placebo (inactive drug). Participation in this study will last approximately 4 weeks and require about 4 outpatient visits to St. Luk's-Roosevelt Hospital Center. About 21 subjects are expected to participate in this study.