I too was having problems getting my pressure down, on 3 drugs with different mechanisms of action and still not getting my pressure down to where my doctor or I wanted it to be. Heard about zona on radio, looked it up, talked to guys at company and ordered it. It took a couple of weeks for me to notice a difference, but I started out at 155/95, with drugs down to 130's/80's, with zona down to 110's/60's. Now am down to 2 drugs and hoping to come off them at some point. Hope this helps. I am a believer.

We (my husband and I ) both tried this product and found it to be very difficult to use and stay in the proper zone. After months of use, it did NOTHING to lower our blood pressure. Also the company refused the money back guarantee because we were a little over the 90 day guarantee and they were RUDE and unprofessional. This product is not what it seems.

Sorry you had a poor experience, but the staff was extremely helpful to me when I purchased the device and has provided ample ongoing support.
I do not believe it is difficult to remain the target range as it based on your own level of exertion. I think this simple device could help many people who struggle on drugs as I did, you just have stay with it.