Although carbohydrate-intake and subcutaneous insulin injection in the insulin dependent diabetics are brought to match with one another, there is often an incongruity between the momentary insulin need and the actual insulin supply, because insulin is resorbed relatively slow from the subcutaneous injection site. While the plasma insulin concentration in healthy persons after carbohydrate-intake reaches its maximum after ca. 45 min, the maximum insulin concentration after subcutaneous application of regular insulin is observed only after ca. 2 h. For this reason, we studied whether a faster rise in the insulin concentration can be obtained by intraperitoneal bolus application of insulin. 5 metabolic healthy volunteers received 20 UI regular insulin diluted in isotonic saline solution injected intraperitoneal. The insulin concentration in the peripherovenous system was examined. In order to prevent severe hypoglycaemia the test persons were connected to a Biostator (so-called artificial Beta-cell), which delivered glucose automatically when the blood glucose concentration fell below the 60 mg/dl - level, and thus avoided a drastic fall of the blood glucose. A rapid increase in the plasma insulin concentration was observed within a few minutes after the intraperitoneal bolus injection of insulin. After ca. 20 min the maximal insulin concentration was reached. Already after ca. 2 h the plasma insulin levels fell off and approached the initial values. Consequently, the changes of insulin concentration after intraperitoneal bolus application of insulin correspond widely to the insulin curve characteristic of metabolic healthy persons after carbohydrate-intake. Thus, the intraperitoneal bolus injection of insulin presents a mode of application, which must be pursued further in the treatment of insulin dependent diabetics.