Access to medicines and the fight against emerging diseases constitute challenges in terms of public health and scientific research. These challenges are all the more important as they involve scientific innovation, the recognition of which is subject to intellectual property rights. However, when there is a solution to these problems, there is often the question of price and competition as well as that of accessibility. The TRIPS declaration, which recognizes the patent for pharmaceutical solutions, creates a gap between the developed countries and the least developed countries. With the Doha declaration, it was thought that the flexibilities would have made it possible to close this gap. On the contrary, we note rather the pre-eminence of the parallel drug market (street drugs) resulting from smuggling and counterfeiting and sometimes from the diversion of licit products by health officials. The circuit of these products is so important that they flood households. The book questions in a more concrete way, the relationship between PGD and street medicine and how can PGD counter its expansion in favor of local medicines?