When combined with changes to behavior, including eating and physical activity habits, prescription medications may help some people lose weight. On average, people who take prescription medications as part of a lifestyle program lose between 3 and 9 percent more of their starting body weight than people in a lifestyle program who do not take medication. Research shows that some people taking prescription weight-loss medications lose 10 percent or more of their starting weight. Results vary by medication and by the person. Weight loss of 5 to 10 percent of your starting body weight may help improve your health by lowering blood sugar, blood pressure, and triglycerides.