Russia is implementing an import substitution program in the pharmaceutical industry, which is especially important against the background of a restrictive policy towards the Russian Federation. Amoxicillin is one of the most popular antibiotics; it is represented on the market by both original and generic drugs. At the same time, the safety issues of produced substances for humans, regardless of the manufacture’s company, are vitally important, since the health of the population depends on their intake. The purpose of the investigation was to study the common toxic properties of domestically produced amoxicillin in comparison with the drug manufactured abroad. Materials and methods. Amoxicillin produced by Barnaul Plant of Medical Preparations LLC was investigated in comparison with the «Hemofarm» amoxicillin (Serbia). Acute toxicity was studied in mice, sub-chronic toxicity was investigated in white male rats. The state of the animals was assessed by integral parameters, indices of peripheral blood and biochemical blood serum analyses, morphological data of the study of internal organs. The results were processed using the program «STATISTICA 10.0». Results. The acute toxicity study did not reveal a difference between the Russian amoxicillin and the comparison drug, the median lethal dose of both drugs exceeded 10,000 mg/kg, which classifies them as low-toxic substances. In a sub-chronic experiment, the presence of a toxic effect on hepatocytes was revealed when large doses of the drug were administered: the activity of AsAT, AlAT was increased (more significantly – by 64 % - when using an imported sample), total and conjugated bilirubin, triglycerides were raised, total serum protein was decreased. There were no significant changes in peripheral blood. Histological studies did not reveal pathological disorders in all the studied internal organs. It is obvious that the identified biochemical abnormalities are not irreversible. Conclusion. The studies have shown that amoxicillin of Barnaul Plant of Medical Preparations LLC and the drug of the «Hemofarm» Company are low-toxic substances. Intragastric administration to rats in doses exceeding a single therapeutic dose for humans did not reveal significant changes in hematological parameters. The nature of the changes in blood biochemical parameters indicates the initial reversible stages of functional disorders of the hepatobiliary system, which were more clearly expressed in the study of the «Hemofarm» amoxicillin.