It all depends on the nature of the drug itself. Chondroprotective agents can be divided into two main groups: natural or synthetic drugs, based on hyaluronic acid (Fermatron, Sinvisk, Ostenil, etc.), and hydrogel-based materials, such as NOLTREX. All the products based on hyaluronic acid are prone to very rapid resorption from the articular cavity, so the period of effectiveness is relatively short. The drugs of the second type, injectable hydrogels- based materials, are more effective. They are fragmented inside the joint very slowly, their effect can last for more than 12 months after a single course of treatment.