Conventional therapeutic models based on the premise of a universal solution are facing a decrease in efficiency, emphasized by the large number of patients who show resistance or who do not respond positively to classic treatments. This perspective highlights the urgency for more precise approaches based on personalized treatments that are adaptable to the specific complexities and unique challenges faced by each patient. Hydrogels are biocompatible and biodegradable systems for well-controlled and targeted administration of therapeutic agents, being formed by 3D reticulated networks of water-soluble polymeric biomaterials, of natural, synthetic, or hybrid origin, with specific intrinsic and extrinsic properties. Due to the easily adjustable porous structure, hydrogels allow the encapsulation of macromolecular drugs, proteins, small molecules, cells, hormones, or growth factors in the gel matrix and their subsequent controlled release. The biomaterials used, the crosslinking methods, the design, and the functionalization strategies in obtaining hydrogels with improved properties are presented. The different possibilities of application are described transdermally, as dressing materials, oral, ocular, spray-able, or injectable, up to the intracellular level. This chapter extensively investigates the advances and unique advantages of hydrogels that enable effective, noninvasive, personalized treatments and provide greater patient comfort for a wide range of applications.