Herbs should be free of side effects within their therapeutic window and when used by a person whose constitution is complimented, not antagonized by the herbs. Whether or not you accept any value to Botanical Medicine, this is Conventional Wisdom amongst herbalists. Side effects from herbs are unwanted, both by herbalists wishing to strengthen, not denigrate homeostasis, and by skeptics who doubt any value to herbs except from placebo or accidental drug effects. On the other hand, a careful evaluation of potential drug therapy starts with the basic understanding that drugs HAVE side effects at the proper dose, and the value must be weighed against the detriment. We all tend to be too isolated in our peer groups, always preaching to our particular choir.
Some physicians feel any self-treatment with biologically active agents is dangerous.
Many people consider this either professional arrogance or the attempt to stifle competition. By extension, docs may rightly presume that any agent capable of promoting change probably has similar potential for side effects. This, of course, leaves any alternative approach in a Catch-22 bind. There is little intrinsic danger in using herbs, since few have the potential for DRUG side effects. The side effects are usually idiosyncratic or idiopathic, and not predictable by drug standards.