Herbal medicines are regulated as drugs in Canada and must therefore conform to labelling and other requirements as set out in the Food and Drugs Act and Regulations, which means that, in contrast to the USA, large numbers of herbal medicines with indication claims are legally on the Canadian market. Prior to assignment of a registration or drug identification number, scrutiny of the composition and the labelling of medicine is required.
On 13 August 1987, following a long discussion between interested parties and experts, an Information Letter was issued by the Canadian Health Protection Branch containing a list of herbs considered hazardous or requiring cautionary labelling. It was reported that products may be sold as foods, drugs or even cosmetics depending on their properties, claims and the manner in which they are used. At that time, herbs and botanicals were acceptable as drugs on the basis of acknowledged claims and quantitative statements of the active ingredient. As a general practice, herbal remedies used for minor self-limiting conditions may be allocated Drug Identification Numbers (DIN), based on a logical pharmacological rationale and bibliographic references which include verified traditional uses that have not been superseded by more recent research and study. Furthermore, the need to provide a specific framework for the registration of herbs and botanical preparations has been identified, and a concept of review involving "Standardized Drug Monographs (SDM)" has been proposed to facilitate registration of those drugs containing herbs that meet the requirements of the monographs. Products making reference to such an SDM would require less individual pre-market scrutiny on a product-by-product basis and would result in more rapid issuance of DIN, but would be balanced with additional post-market compliance monitoring and activity. Combinations of herbs outlined in such monographs would be accepted if justified on sound therapeutic principles. Claims in respect of prevention or treatment of serious diseases and those which are inappropriate for self-diagnosis and treatment are prohibited within this procedure .
On 5 January 1990, another Information Letter was issued to clarify the policy of the Health Protection Branch on herbal medicines, to outline the regulatory requirements, and to advise on the mechanisms for applications for DIN for these products. It was clearly stated that the most important factors in determining whether a herbal product is considered to be a food or a drug are the pharmacological activity of the ingredients, the purpose for which the product is intended, and the representations made regarding its use. Herbal medicinal products are in this Information Letter classified into two major groups:
- Herbs listed in pharmacopoeias and major pharmacological reference works; they generally have their properties, dosage, indications, and contra-indications for a well established use. Products containing such herbal ingredients are reviewed in the same manner as other drug products and are widely available on the market either on prescription or as non-prescription drugs.
- Herbs which have received relatively little attention in scientific literature and therefore may not be well known in Canada. Nonetheless, there is literature available on their traditional use on an empirical basis, and these references are considered to be useful in supporting the acceptability of herbal drug products. It was expected that herbal medicines from this group would be used for minor self-limiting conditions. These products which are based on traditional or folkloric use should be designated as traditional medicines, and some details for application for DIN have been announced.
The review of DIN applications involving standardized drug monographs (SDM) should enable a manufacturer to certify that products meet the conditions outlined in the SDM .
In October 1990, guidelines on "Traditional Herbal Medicines" were published by the Health Protection Branch, by authority of the Minister of National Health and Welfare, to assist manufacturers in completing applications for a DIN and in labelling products that fall within the category of Traditional Herbal Medicine (THM), as outlined in the Information Letter of 5 January 1990. Applications must include a draft version of the label with a clear claim or indication for the use of the traditional herbal medicine. The claim should be supported by references. If an SDM is available for a herb, and if the proposed claims are within the scope of the monograph, a statement to this effect is an acceptable replacement for other references. Terms such as "tonic, supplement, purifier, depurative" and other similar wordings are not accepted. Some combinations of herbs that seem illogical e.g., diuretics combined with laxatives and those with contradictory effects are regarded as questionable.
The assessment is primarily based on traditional references for efficacy and dosage. The claims are restricted to those that are acceptable for self-monitoring. If there are safety concerns, modern research will be taken into account instead of traditional references .