In New Zealand, herbal medicines are dealt with in two ways according to the Medicines Act of 1981. On the one hand, any herbal remedy may be manufactured and sold if requested for the expressed purpose of treating a particular person. This remedy must not contain a scheduled medicine and must be supplied under a designation that specifies the plant and the process of manufacture of the remedy, without any other name and without any written recommendation as to the use of the remedy. In these cases, no licensing and no assessment is required.
On the other hand, for any herbal medicine not covered by the above-mentioned conditions, marketing approval is required. The assessment of herbal medicines is carried out in the same way as for proprietary medicines by the Therapeutics Assessment and Utilization Section of the Department of Health. The application includes control of active ingredients and excipients, method of manufacture, control tests of the finished product, labelling, stability etc.
The efficacy of herbal medicines is not evaluated critically. Often there are hardly any clinical data for efficacy, since most of these remedies are prescribed on a patient basis. Supporting evidence for efficacy may include references in standard books, unless this information has been superseded by more recent research data. Indication claims are restricted to self-limiting conditions. In some cases, where there is concern about safety, toxicity data have to be provided; if not, a withdrawal from the market may be the consequence .