Many adults over 40 take more than one prescription, over-the-counter medicine, or supplement every day. While these can help control blood pressure, cholesterol, pain, or other conditions, they sometimes interact with each other—or with everyday foods and drinks—in ways that reduce effectiveness or increase side effects. Grapefruit juice, dairy products, leafy greens, alcohol, and even common pain relievers can change how a medicine works in your body. The good news is that most of these interactions are predictable and avoidable once you know what to look for. This quiz covers practical, everyday situations involving common medications and foods. The questions are based on well-established medical guidance from sources such as the FDA, major medical associations, and pharmacy resources. No specialized knowledge is required—just common sense and careful reading. Take your time, choose the best answer for each question, and use the explanations to build safer habits. Knowing these basics can help you stay independent and feel more confident managing your health.