With obesity-related diabetes, it is possible to use biguanides, which have a slight anorectic effect. The presence of side effects in biguanides often complicates their long-term use, especially in elderly patients who have a history of chronic diseases of the lungs, heart, kidneys, and liver. In such cases, it is advisable to prescribe anorectic drugs that simultaneously affect carbohydrate metabolism.One of these drugs is p-ethyl-a-methyl-3-fluoromethylphenethylamine hydrochloride (minifage, ponderal), which has a stimulating effect on the central nervous system. Fenfluramine reduces the supply and synthesis of monoamines (5-hydroxytryptamine) in the diencephalic regions of the brain, due to which there is a decrease in food requirements and a decrease in body weight.A number of researchers have shown that the hypoglycemic effect of the drug occurs due to peripheral action. Fenfluramine affects the extraneuronal oxidation of monoamins and reduces the level of tryptophan in the blood. T. Pssquire in experiments on rats confirmed that this effect of the drug is achieved by improving the sensitivity of peripheral tissues to insulin, especially muscles.Some researchers observed a decrease in plasma fatty acids and cholesterol levels during treatment with ferfluramine.However, the issue of the effect of the drug on the residual secretion of the C-peptide of b-cells of the pancreas during treatment with fenfluramine is not covered in the literature available to us.In our study, 26 patients with obesity (the control group consisted of 18 healthy subjects who had previously impaired glucose tolerance) showed that fenfluramine restores phase I of insulin secretion on the background of an intravenous load with glucagon or glucose, and compensation for diabetes mellitus during treatment fenfluramine is apparently associated not only with a direct stimulating effect on the -cells of the islets of Langerhans but also with its peripheral effect.