The study of insulin pharmacokinetics must help for a better understanding of clinical phenomenons commonly observed among diabetic patients, when insulin therapy is administered either intra-venously (I.V.), or subcutaneously (S.C.). We realized this work in a population of insulin-dependent diabetics. None of the subjects had significant levels of anti-insulin-antibodies. We analysed the absorption profiles (SC(t] of radio-iodine labelled insulin after a subcutaneous injection, the plasmatic profiles (P(t] after an intra-venous bolus of cold insulin. We demonstrate that, using a convolution calculation, it is possible to predict the plasmatic in insulin kinetics after subcutaneous injection or during S.C. infusion, even if the infusion rates are varying. An estimation of the proportion of insulin which is degraded at the injection site can easily be done. This model may be useful for a better understanding of the kinetics of insulin among diabetics, but also to evaluate new modes of insulin administration.