Oxyethylammonium methylphenoxyacetate is an adaptogenic immunomodulator with a complex mechanism of action. It can be successfully used for treatment, prevention and restoration in case of flu and cold, and to improve working capacity in asthenia, including conditions developed following COVID‑19. Clinical investigation of the effect produced by oxyethylammonium methylphenoxyacetate demonstrates its effectiveness under extreme climate and geographic conditions, during physical and mental overload, exercise, viral infections, severe infectious pathology, and all diseases associated with a weakened immune system. Based on conducted clinical trials of oxyethylammonium methylphenoxyacetate, no adverse effects were found and good tolerability was observed. Due to good compatibility of oxyethylammonium methylphenoxyacetate with other agents, it can be included into complex rehabilitation programs as an independent or/and complementary agent. This increases effectiveness of the conducted treatment and improves the diagnosis.