For the fi rst time there have been carried out scientifi c research of the infl uence of medicinal plants extracts from blackberry (Ribes nigrum), fl ax (Linum usitatissimum), corn stigmas (Maydis stigmata) and hawthorn (Crataegus monogira) on endocrine pancreas β-cell function, functional activity of thyroid hormones, that have given a possibility to reveal stimulating of these glands at the incipient stages of experimental diabetes. There was presented the complex study of interdependency of endocrine pancreas, thyroid hormones in alloxan induced diabetes. The paper showed that during experimental diabetes endocrine glands increase their activity, as the adapting reaction to endogen metabolic stress caused by β-cells dysfunction. Experimental groups which without medicinal plants extract administration was determined the decrease of insulin secretor cells function. Medicinal plants extracts manifests biosimulative effects on β-cells from Langerhans isles of endocrine pancreas.