I have been using one drop of Goldenseal on my toothbrush, two times daily. I have had issues of gum recession and am concerned about thinning enamel. I have a few very good things to say about this product. First of all, it is a subjective statement, but my husband thinks that my teeth look better. Less subjective, at my dental cleaning this past week, the hygienist said that my teeth looked very clean and that she could barely find anything to clean. I have typically had this said to me in the past, but at recent visits the comments had not been quite as positive. I had also changed, during this period, from a glycerine-containing toothpaste, to a homemade one without. Thirdly, I had several days when a bleeding gum issue had me quite concerned, to the point that I scheduled an emergency appointment w/ a dental provider. I decided to try putting the goldenseal on my floss and then flossed the area gently. The issue resolved. It came back briefly and then went away again and so far hasn't returned. I am thankful. One caution: the product can burn or sting your lips a bit, particularly if they are chapped.