Several factors, including age and genetics can affect how your body will respond to certain medications.

According to an article published by Harvard Medical School, things like food, vitamins and over-the-counter medicines can change how medicine works in the body. For example, supplements like calcium can impact blood pressure medication while St. John’s Wort and turmeric have known interactions with certain heart medications.

Grapefruits are also known to interact with statins, as they contain a compound that interferes with an enzyme in your gut. If this enzyme is blocked, it may result in higher levels of the medication in the bloodstream.

To lower your risk for interactions, you should use the same pharmacy for all prescriptions and inform your provider of medications you are taking including supplements. And any time you’re prescribed something new, ask your doctor how the drug works, possible side effects and if there’s anything you should avoid while taking the drug.