Different models for medicines regulation exist across the world, and in many countries medicines regulatory procedures are still largely ineffective, due to chronic shortages of human and technical resources. Regulatory agencies in developing countries are resource constrained in terms of staffing, standards, systems, and training. As part of the normative role that WHO plays, most of the standards, norms and guidelines have been developed, and the extent of implementation varies from one region to the other. There are a number of factors that explain observed weaknesses of medicines regulation, and these differ from country to country and depend also on the health system. Countries may vary regarding their registration system and not all of them can implement a comprehensive medicine evaluation and registration system. The WHO Medicines Regulatory Package is a collection of tools aimed at supporting the work and decision making processes of National Medicines Regulatory Authorities (NMRAs).