Biological medicines have represented a notable advance in the treatment of diseases that are generally serious and chronic (but not only). In many cases, these are already therapeutically essential medicines, but whose average cost is much higher than that of chemically synthesized medicines. They may require more than 40% of pharmaceutical resources in certain hospitals. It is an upward trend, because it is known that a high percentage of the products currently in clinical development are biotechnological. Biosimilars, equivalent biological products but at a lower price, contribute to savings in pharmaceutical bills without reducing access to quality biological therapies. Biosimilars therefore consolidate the guarantee of quality healthcare coverage for future generations of patients.