It depends. Some medications will be unaffected by changing your diet while on Nutrisystem and losing weight. Other medications may need to be adjusted simply due to a change in the foods you eat, even before you start to lose weight (insulin, for example). Still other medications may interact with ingredients in our food, or with other changes to your diet. You should talk to your doctor before beginning Nutrisystem, or any weight loss or exercise program, to determine if your medications need to be adjusted prior to starting.