Quality Ingredients
Ninety-nine percent of the herbs used by American companies do not come from the US. They are imported from Eastern Europe and from many third-world countries such as India, China, and Mexico.
Unfortunately, these countries use large amounts of insecticides and pesticides in the growing of their herbs. DDT is still commonly used in Asia and Mexico, whereas organo-phosphate nerve-gas based insecticides are commonly used throughout Eastern Europe.
It's also worth noting that most of the areas in which these herbs are grown in these countries are heavily polluted. The herbs are inundated by polluted rain and irrigated by polluted rivers. In Eastern Europe, for example, there have been no environmental laws for decades. Rivers have been used as open sewers. Everything from chemical toxic waste to radioactive waste(no joke) has been dumped into these rivers.
The reason most American companies use these herb sources, regardless of the problems just mentioned, is that they are cheap. Good quality organic and wildcrafted herbs cost as much as 20 times more. Before you use any company's herbal formulations, you should learn where their herbs come from.