The porcine-extracted monocomponent insulins and human insulin (Novo) obtained by enzymatic conversion of porcine insulin had similar effects on glycemia balance when compared by means of an artificial pancreas during two 48-h studies 2 or 3 days apart. There was no significant difference between the maximum and minimum blood glucose circadian variations, the glycemic drops, and the Schlichtkrull coefficient. The speed of increase and decrease of glycemia during meals was slightly slower with human insulins than with porcine insulins, but the difference was not significant. Although comparable, the insulin requirements (per gram of ingested carbohydrate) were proportionately greater in the morning than during the rest of the day; the baseline requirements were also similar, but showed a trend toward increase during the day with both insulins.