I Have A Problem With PVC's. I've Had Stress Tests.

I have a problem with PVC's. I've had stress tests. My doctor assures me I am not at risk for anything major. However, i am looking at a vitamin supplement that has saw palmetto, collagen and haulyronic acid in it. (sorry for spelling) I am loathe to take anything that might set my heart racing.
I am an otherwise healthy 60 yr old female who watches what she eats and does 30 minutes of exercise a day.