As mentioned, WTO Members have a certain leeway to determine what is patentable, notably with regard to the patentability of natural products and therapeutic methods.

Countries concerned with “bio-piracy” may wish to exclude from patentability substances found in nature, as well as the use of known products, in order to prevent misappropriation. In addition, it would seem logical that a country that broadly excludes methods of medical treatment, also broadly exclude new therapeutic uses for known products. Nevertheless, given the territoriality of the patent system, a country that prevents the patenting of uses under its national law cannot force other countries to follow the same approach. In the absence of international rules on the matter, nothing will prevent a country from declaring patentable (if the legal requirements are met) what is not deemed patentable in another country.

From the perspective of public health, the granting of patents over methods of therapeutic treatment seems undesirable, since it would reduce access to health care, particularly for the poor, while it is unlikely to promote in any manner the development of new TRM-based therapeutic methods.

Though WTO Members may limit the scope of patentability, some developing countries may worry that it could hinder investment in local bio-prospecting or research activities that may lead to patents on TRM-based products and successful commercialization. It must be borne in mind, however, that developing countries possessing TRM knowledge often lack the financial resources and the research and industrial capabilities to scientifically identify and isolate the compounds that explain the therapeutic effects of certain traditional medicines. In addition, TRM healers and local/indigenous communities generally lack the skills and resources necessary to follow the complex patent procedures and, in particular, to face the costs of registration and enforcement of IPRs both locally and abroad. Even with a wide scope of patentability, these factors seriously limit the practical utility of such an approach.