Introduction Mucosaadhesive gels are applied to mucous membranes. Advantages: 1) presence of the active substance on the mucosal surface is prolonged; 2) it is possible to increase the concentration of active ingredient and implement local therapeutic effect with reduced probability of side effects; 3) the consumption of pharmaceuticals is reduced. Purpose To study the effectiveness of oral injection of quercetincontaining gels on the parameters of the functional state of the liver and fat metabolism in rats against the background of the experimental metabolic syndrome. Methods. Studies were carried out on male Wistar rats, with metabolic syndrome simulated by means of addition to mixed fodder of 15% unrefied sunflwer oil, lincomycin (60 mg/kg) in drinking water for the first 5 days of intraperitoneal administration of cyclophosphane (25 mg/kg) a day later. Every day, 0.5 ml of mucosal gels with quercetin and inulin, with quercetin and imidone or with quercetin and hyaluronic acid were applied onto the mucous membrane of the mouth. Duration constituted 35 days. The content of triglycerides was determined in the liver homogenates, in the serum – the activity of alanine aminotransaminase and alkaline phosphatase, the content of triglycerides, total cholesterol and bilirubin. Results Modeling of metabolic syndrome in rats caused an increase in triglycerides, cholesterol, and “liver” markers. Prophylaxis by daily application of mucosal quercetincontaining gels, with some advantage of “Quertulin” (quercetin + inulin), had a expressed therapeutic and prophylactic effect, preventing metabolic disturbances. Conclusion Local (oral) application of quercetincontaining gels can effectively prevent disorders of fat metabolism and liver function. It is proposed to introduce a dosage form “mucosaadhesive gels” with the introduction of various drugs into medical practice for prevention and treatment of the most common diseases