Background: Acute viral infections due to widespread, high contagiousness and rapid development of viruses resistance to used drugs (medicines) is one of the greatest challenges of modern medicine. Therefore, the search for new approaches and methods for treatment and prevention of viral etiology is very relevant. The aim of this article was to review one such approach called bio-regulatory, which allows us to solve the above problem. It is carried out through the use of complex bio-regulatory medications. In this article was reviewed complex bio-regulatory medications for viral diseases – Engystol, it is antiviral immunomodulator of German pharmaceutical company “Biologische Heilmittel Heel GmbH” which is widely used in a variety of viral diseases in case of children and adults thanks to its favorable safety profile and proven efficacy. Conclusions: National and foreign doctors in case of many viral diseases have experience of successful long-term use of complex bio-regulatory medications Engystol. Results of scientific and clinical studies show that Engystol is universal antiviral immune-modulator with proven efficacy in a wide range of viral diseases in children and adults. It has a high safety profile. It is used both independently and as part of complex treatment regimens. It goes well with any medicines, reducing their side effects on the body.