I paste here the answer of a very knowledgeable friend of mine when I asked him about goldenseal:
"First of all I wish companies would stop using goldenseal. Goldenseal has been over harvested for a long time and there has been talk for years about putting it on the Endangered Species list. There are other plants with the same constituents, such as barberry and Oregon grape root, that are much more plentiful. But many companies will not use them because they are less known and these companies know people are more likely to buy something they have heard of and therefore feel more comfortable with."