It is definitely true that some of our modern medicines came from herbs or barks that were used in folk medicine. (Digitalis, aspirin, and quinine come to mind.) It is also true that there are some fairly decent studies of some other herbal preparations, such as echinacea, which fail to demonstrate any benefit. Vitamin C is another one where clinical efficacy for anything other than scurvy has been difficult to prove.
The majority of herbal preparations are at least harmless, but some are not. The ephedra contained in a number of herbal diet preparations causes arrhythmias. Valerian in higher doses or over time can be significantly toxic to the liver.
I don't have any problems with people augmenting traditional medical care with herbal medicine or other alternatives, so long as they have done their homework about what's in what they are taking, and what the risks and benefits are (and this information, today, is fairly easily available) and so long as they don't abandon evidence-based treatment modalities in favor of things for which the data are not nearly as solid.
The majority of herbal preparations are at least harmless, but some are not. The ephedra contained in a number of herbal diet preparations causes arrhythmias. Valerian in higher doses or over time can be significantly toxic to the liver.
I don't have any problems with people augmenting traditional medical care with herbal medicine or other alternatives, so long as they have done their homework about what's in what they are taking, and what the risks and benefits are (and this information, today, is fairly easily available) and so long as they don't abandon evidence-based treatment modalities in favor of things for which the data are not nearly as solid.