Background: Currently, one of the main problems that happens in the treatment by extracorporeal methods of hemosorption is systemic shifts in homeostasis. Among these complications the most significant are blood cells traumatization and hemorrhage. Direct physical contact of blood with sorbent surface causes activation of a multistage reaction of thrombosis. Now, new methods of hemosorption using non-traumatic sorbents are being actively developed. Wide introduction of nanotechnological preparations (magnetite nanoparticles) in clinical medicine allows improving methods of hemocorrection, creating a new class magnetically sorbent. The aim of this study is to know the activity of magnet-controlled sorbent inhibiting the aggregation of platelets in an in vitro model. Materials and Methods: 0.9% NaCl, magnetite nanoparticles of magnet-controlled sorbent (MCS-B brand). Object of research: platelets in relatively healthy volunteers. Quantitative determination aggregation of platelets activity by using aggregometer A-1 was carried out by the Bornov's method in the modification of Zachary and Kinah. Results and discussions: The results of the study showed that the use of NaCl saline solution shifts the colloidal suspension equilibrium of platelets towards a significant (P<0.001) increase in the rate and index of their aggregation. For the first time, the effect of 0.9% NaCl on function of platelets makes us reconsider the concept of safety of infusion solutions in patients with initial signs of platelet disorders hemostasis. On the contrary, the use of MCS-B nanoparticles significantly revealed (P<0.05) an increase in the stability of colloidal suspension of platelets. This is an important pathogenetic factor which affects the occurrence of correction of hemostasis in conditions of blood clotting disorders.