Request Appointment Media Pass Login News Network By Shawn Bishop, Mayo Clinic - Senior Communications Specialist Supplements to Avoid when Dealing with High Blood Pressure March 12, 2010 Supplements to Avoid when Dealing with High Blood Pressure March 12, 2010 Dear Mayo Clinic: What are the dangers of taking over-the-counter supplements? I am on blood pressure medication and have heard that there are some supplements that may interfere. Answer: You 've heard correctly. Some supplements should be avoided when you are dealing with high blood pressure. Yet, preliminary evidence shows that a couple of supplements may be beneficial in your situation. While supplements may be labeled "natural" and don 't require a prescription, they can affect the body in many ways. Supplements can interact with medications, change the body 's metabolism and cause side effects. Baseline advice for any supplements is to talk...