Effects of Sucralose on Drug Absorption and Metabolism (The SweetMeds Study)

Background: Artificial sweeteners like sucralose are found in many foods and drinks. Sucralose might affect hormones and cause health changes. Objective: To see if sucralose changes how medicines are absorbed and processed, how hormones are secreted, gut bacteria, and how fat cells are metabolized. Eligibility: People ages 18-60 who: * Are black or Hispanic * Weigh more than 110 pounds * Have a body mass index of 25-40 * Do not have a condition that requires drug treatment Design: Participants will be screened with: * Medical history * Physical exam * Blood, heart, and urine tests Participants must not eat or drink anything with artificial sweeteners throughout the study. Over 7 days, Participants will answer questions, and give daily urine samples and 1 stool sample. Participants will repeat these throughout the study. Overnight Visit 1: participants will fast starting the night before. They will get breakfast at the visit. The visit includes: * An IV will be placed in the arm. Participants will get 2 tablets of medicines. Blood will be drawn several times over 24 hours. * A piece of fat tissue may be taken from the abdomen (biopsy). * Participants will have a sweet drink. Blood samples will be taken over 2 hours. Then participants will be randomly assigned to take either a sucralose capsule or placebo. They will take it twice a day for 2 weeks. They will complete two 24-hour food diaries. Overnight Visit 2 repeats Visit 1 except the biopsy. Then participants will take the capsules for another 2 weeks. Overnight Visit 3 repeats Visit 1. Participants may be contacted by phone within 4 weeks after they finish.