DiarioFarma. Scientific societies, at a general level, agree on the great contribution that biosimilars can make to the sustainability of the health system. Some specialists even recognize the advances of some of them in terms of facilitating the route of administration or bioavailability. There is also no lack of clinical voices that highlight the appearance of the biosimilar as a lever for the generation of future innovations. But having said this, and despite the fact that they all show their confidence in the rigor of the European Medicines Agency (EMA) when approving a drug, they cite the uncertainties associated with possible adverse effects or loss of efficacy when exchanging the original for the biosimilar, as well such as the requirements (apparently insufficient, in the opinion of specialists) for the extrapolation of indications, to explain the still low penetration of these products. This was revealed at the conference 'Biosimilar medicines: access to clinical practice', organized by Fuinsa, and in which representatives of up to eight medical specialties participated.