The analysis of the clinical application effectiveness of the drug Liсopid® (the substance is glucosaminylmuramyldipeptide – GMDP), is discussed. Many years of experience using the drug Liсopid in diseases associated with the mucous layers of the body, forming the mucosal immunity system, has shown high efficiency in therapy and prevention. On the example of clinical application showing the systemic use of the drug Licopid® in ophthalmology, the treatment of respiratory diseases, including acute respiratory children and adults infections, tuberculosis; diseases of the gastrointestinal and urogenital tracts, it has been demonstrated that Liсopid® is effective in the immunoprophylaxis of various diseases, prevents relapse of acute respiratory infections, bacterial and herpetic children and adults infections, and is effective in the treatment and prevention of seasonal and allergic diseases. The study of the mechanism of Licopid® action, a wide range activity and the side effects absence are the basis for recommendations on the widespread use of GMDP in medical practice, immunotherapy and immunoprophylaxis. © 2020 Meditsina Publishers. All rights reserved.