Prescription Weight Loss options available at Lotus Health in Brunswick GA. 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.