Supplements are commonly used to enhance our overall health by filling in nutritional gaps in our diet. However, it is essential to be aware of potential interactions when combining certain supplements or medications. In this article, we will discuss 13 supplement or medication combinations that should be avoided for optimal health. These combinations include magnesium and calcium, zinc and copper, iron and green tea, fish oil and ginkgo biloba, melatonin and sedating herbs, red yeast rice and niacin, vitamins A, D, E, and K, potassium and calcium, St. John’s Wort and antidepressants, CoQ10 and diabetes medication, garlic and blood thinners, vitamin K and blood thinners, echinacea and blood thinners, and antibiotics and iron. It is crucial to consult with a healthcare professional before starting any new supplement regimen or combining supplements with medications to ensure personalized guidance and safety.