The article defines the original drug (OD) and examines the history of the appearance of generic drugs (GD), as well as the evolution of views to prove their bioequivalence to OD. The question is considered to what extent pharmacokinetic equivalence can guarantee the clinical equivalence of OD and GD. The data on the rules of registration of GD in different countries are provided. A brief overview of various types of studies comparing the clinical efficacy and safety of OD and GD (meta-analyses, randomized controlled trials, observational studies, description of clinical cases) and their main results is given. The results of a number of observational studies on the replacement of OD with GD and its consequences are presented. The existing system of current quality control of GD is described, numerous cases of recall of GD due to detected violations during their production are given. It is mentioned about individual cases of clinical inefficiency of GD and their side effects identified by the practical physicians. It is concluded that a qualitatively produced GD with proven pharmacokinetic equivalence to OD is able to provide therapy of the same quality as OD. However, numerous cases of the appearance of GD on the pharmaceutical market, which does not correspond to the quality of OD, make us somewhat wary of therapy based on VP. Both the practitioner and the patient should know which of the drugs prescribed by the international nonproprietary name is OD and which is GD.