An in vitro experimental study was conducted to evaluate the antiradical and immunomodulatory properties of injectable formulations containing 1% and 1.4% hyaluronic acid (HA) for the prevention and correction of conditions associated with excessive free radical activity, as well as the regulation of imbalances in oxidative-reduction processes and energy metabolism. Materials and methods. The experiment utilized model systems generating reactive oxygen species (ROS). To assess immunomodulatory effects, oxygen-dependent metabolism and ROS generation by phagocytes were simulated. Parameters of oxygen-dependent metabolism in blood were analyzed after adding 1% and 1.4% HA preparations, both in unstimulated and zymosan-stimulated conditions. Results. Both HA-containing formulations significantly reduced ROS generation, indicating their ability to neutralize free radicals and protect cells from oxidative stress. The antioxidant and antiradical properties of HA correlated with decreased ROS production, suggesting utility in mitigating oxidative damage. Additionally, the 1.0% and 1.4% HA preparations enhanced immune response efficiency by elevating basal and stimulated phagocyte activity and improving their functional reserve. Conclusion. The findings demonstrate the high efficacy of injectable hyaluronic acid formulations (1% and 1.4%) in preventing and correcting conditions linked to excessive free radical activity and imbalances in redox processes and energy metabolism. © 2025 Elsevier B.V., All rights reserved.