Quality control
Most herbal preparations and some of the substances
listed above are categorised by the Register of
Therapeutic Goods as 'listed drugs'. These drugs
are not checked as rigorously as 'registered drugs'
such as antidepressants, for standards of preparation
or evidence of their effectiveness. Some of these
compounds have been shown to be contaminated with
other substances, and to vary in the dosage contained
in each tablet.
